Detector Components and Methods for Transmitting Computed Tomography Scans

Abstract

This application discloses a detector assembly and method for transmitting computed tomography scans. The detector assembly may include detector micro-blocks, detector blocks, etc. The detector micro-block may include detector units arranged side-by-side along a second direction. Each detector unit may include a crystal element and an optical sensor array. The crystal elements may be arranged in rows along the second direction and in columns along a first direction perpendicular to the second direction. Each crystal element may include a first end and a second end, extending from the first end to the second end along a third direction perpendicular to both the first and second directions. The optical sensor array may include optical sensors arranged along the first direction.

Description

[0001] Cross-references

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 579,949, filed August 31, 2023, and U.S. Patent Application No. 18 / 617,620, filed March 26, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This specification relates to the field of medical technology, and in particular to detector assemblies and methods for use in emission computed tomography (ECT). Background Technology

[0004] Spatial resolution is one of the most important performance indicators of an ECT detector. Spatial resolution is typically improved by reducing the crystal size of the crystal elements in the ECT detector. However, reducing the crystal size leads to an increase in the number of crystal elements in the ECT detector, thereby increasing the complexity of the ECT detector structure, the amount of data processed, and reducing the temporal resolution of the ECT detector.

[0005] Therefore, there is an urgent need to provide an ECT detector assembly and a method for determining the depth of action (DOI) in the ECT detector, so as to improve the spatial resolution of the ECT detector without increasing the number of crystal elements in the ECT detector or reducing the temporal resolution of the ECT detector, thereby improving the accuracy of ECT imaging. Summary of the Invention

[0006] One embodiment of this specification provides a detector microarray for transmitting computed tomography scans. The detector microarray may include detector units arranged side-by-side along a second direction. Each detector unit may include a crystal element and an array of optical sensors. The crystal elements may be arranged in rows along the second direction and columns along a first direction perpendicular to the second direction. Each crystal element may include a first end and a second end, extending from the first end to the second end along a third direction perpendicular to both the first and second directions. The optical sensor array may include optical sensors arranged along the first direction. In each crystal element row, the first end of the crystal element may be optically coupled to an optical sensor in the optical sensor array, and in each crystal element column, the second end of the crystal element may be configured with an optical bridge.

[0007] In some embodiments, for each crystal element column in each detector unit, an optical splitter may be configured between each pair of adjacent crystal elements in the crystal element column. The optical splitter may extend from a first end of the corresponding pair of adjacent crystal elements but not to a second end of the corresponding pair of adjacent crystal elements.

[0008] In some embodiments, the second ends of the crystal elements in each crystal element column are integrated into a single unit as an optical bridge.

[0009] In some embodiments, the optical bridge for each crystal element column may include an optical propagation medium disposed between each pair of adjacent crystal elements in the crystal element column. The optical propagation medium may extend from the second end of a corresponding pair of adjacent crystal elements to an optical separator between the corresponding pair of adjacent crystal elements.

[0010] In some embodiments, for each detector unit, an optical splitter may be configured between each pair of adjacent crystal element columns in the detector unit. The optical splitter may extend from a first end of a crystal element in a corresponding pair of adjacent crystal element columns to a second end of a crystal element in a corresponding pair of adjacent crystal element columns.

[0011] In some embodiments, for each crystal element column of each detector unit, an optical splitter may be configured between each pair of adjacent crystal elements in the crystal element column. The optical splitter may extend from a first end of a corresponding pair of adjacent crystal elements to a second end of a corresponding pair of adjacent crystal elements. The optical bridge may include an optical propagation medium that covers the second end of the crystal elements in the crystal element column.

[0012] In some embodiments, a second optical bridge may be configured between each pair of adjacent detector units in the detector microblock.

[0013] In some embodiments, an optical splitter may be configured between each pair of adjacent detector elements in the detector microblock. The optical splitter may extend from the second end of the crystal element in the corresponding pair of adjacent detector elements, but not to the first end of the crystal element in the corresponding pair of adjacent detector elements.

[0014] In some embodiments, for each detector unit, two crystal elements may be arranged along a first direction in each crystal element column of the detector unit, and two crystal elements may be arranged along a second direction in each crystal element row of the detector unit.

[0015] In some embodiments, each crystal element may include a long side along a first direction and a short side along a second direction. The length of the long side along the first direction may be greater than the length of the short side along the second direction.

[0016] In some embodiments, the ratio of the length of the longer side along the first direction to the length of the shorter side along the second direction may be greater than 1 and less than 5.

[0017] In some embodiments, the crystal element array and the detector microblock may each have a U-shaped structure or an approximately inverted U-shaped structure.

[0018] One embodiment of this specification provides a detector block for transmitting computed tomography scans. The detector block may include multiple detector micro-blocks as described above, and the multiple detector micro-blocks may be arranged in a block array.

[0019] In some embodiments, the short sides of the crystal elements in the plurality of detector microblocks may be parallel to each other.

[0020] In some embodiments, the short side of the crystal element of one or more first detector microblocks in the plurality of detector microblocks may be perpendicular to the short side of the crystal element of one or more second detector microblocks in the plurality of detector microblocks.

[0021] In some embodiments, each pair of adjacent detector microblocks in a plurality of detector microblocks may include a first detector microblock and a second detector microblock to form a checkerboard structure. Each row of detector microblocks in the detector block parallel to the diagonal direction of the block array may have the same orientation, and the orientations of adjacent rows of detector microblocks parallel to the diagonal direction may be perpendicular to each other.

[0022] In some embodiments, a detector block may include a first sub-block and a second sub-block. Each sub-block may include a plurality of detector micro-blocks. The detector micro-blocks of each first sub-block may have a first arrangement, and the detector micro-blocks of each second sub-block may have a second arrangement, which is different from the first arrangement.

[0023] One embodiment of this specification provides a method for identifying the location of photon-gamma interactions. The method can be executed on a computer including one or more processors and one or more storage devices. The method may include acquiring output information of an optical sensor of the aforementioned detector microarray; and determining, based on the output information of the optical sensor, the location information of the photon-gamma interactions occurring in the crystal element of the aforementioned detector microarray.

[0024] One embodiment of this specification provides a method for transmitting computed tomography (ECT) scans. The method can be executed on a computer including one or more processors and one or more storage devices. The method may include acquiring output information from optical sensors in a plurality of detector micro-blocks of a detector block; dividing the output information into a first subset and a second subset, the first subset corresponding to optical sensors in one or more first detector micro-blocks and the second subset corresponding to optical sensors in one or more second detector micro-blocks; generating a first ECT image based on the first subset; and generating a second ECT image based on the second subset.

[0025] In some embodiments, the first image resolution of the first ECT image along the first direction may be greater than the second image resolution of the second ECT image along the first direction, and the first image resolution of the first ECT image along the second direction may be less than the second image resolution of the second ECT image along the second direction.

[0026] In some embodiments, the method may further include generating a third ECT image based on a first subset and a second subset.

[0027] 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 from the following description and the accompanying drawings, or from an understanding of the production or operation of the embodiments. The features of this application can be implemented and obtained by practice or by using various aspects of the methods, means, and combinations set forth in the detailed examples discussed below. Attached Figure Description

[0028] This specification will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting; in these embodiments, the same reference numerals denote the same structures, wherein:

[0029] Figure 1 These are schematic diagrams of exemplary imaging systems according to some embodiments of this specification;

[0030] Figure 2 This is a schematic diagram of an exemplary crystal assembly according to some embodiments of this specification;

[0031] Figure 3A and Figure 3B This is a schematic diagram of exemplary photonic gamma interactions occurring in an exemplary crystal assembly according to some embodiments of this specification;

[0032] Figure 4A This is a schematic diagram of an exemplary crystal assembly according to some embodiments of this specification;

[0033] Figure 4B This is a schematic diagram of an exemplary crystal assembly according to some embodiments of this specification;

[0034] Figure 5A This is a schematic diagram of an exemplary detector micro-block according to some embodiments of this specification;

[0035] Figure 5B This is a schematic diagram of a rear view of an exemplary detector micro-block shown according to some embodiments of this specification;

[0036] Figure 5CThis is a schematic diagram of a right view of an exemplary detector microblock shown according to some embodiments of this specification;

[0037] Figure 5D This is a schematic top view of an exemplary detector micro-block shown according to some embodiments of this specification;

[0038] Figures 6A-6F This is a top view schematic diagram of an exemplary detector block according to some embodiments of this specification;

[0039] Figure 7 This is a block diagram of an exemplary processing apparatus according to some embodiments of this specification;

[0040] Figure 8 This is a flowchart illustrating an exemplary process for determining the location of photon-gamma interactions in a detector microarray according to some embodiments of this specification;

[0041] Figure 9 This is a flowchart illustrating an exemplary process of ECT according to some embodiments of this specification; and

[0042] Figure 10 These are exemplary reconstructed images shown according to some embodiments of this specification. Detailed Implementation

[0043] To more clearly illustrate the technical solutions of the embodiments in this specification, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this specification. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0044] It should be understood that the terms “system,” “device,” “unit,” and / or “module” used herein are one way to distinguish different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0045] As indicated in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0046] It is understood that although terms such as "first," "second," "third," and "fourth" may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element, without departing from the scope of exemplary embodiments of the present invention.

[0047] Spatial and functional relationships between elements (e.g., between crystal elements) can be described using various terms, including “connection,” “engagement,” “interface,” and “coupling.” Unless explicitly described as “direct,” the relationship between a first element and a second element described in this specification includes a direct relationship where no other intervening element exists between the first and second elements, as well as an indirect relationship where one or more intervening elements (spatial or functional) exist between the first and second elements. In contrast, when an element is described as being “directly connected,” engaged, interfaced, or coupled” to another element, no intermediate element exists. Other terms used to describe relationships between elements should also be interpreted similarly (e.g., “between” vs. “directly between,” “adjacent” vs. “directly adjacent,” etc.). In this application, the term “and / or” may include any one or more of the relevant listed items or a combination thereof.

[0048] Flowcharts are used in this specification to illustrate the operations performed by the system according to embodiments of this specification. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the steps can be processed in reverse order or simultaneously. Furthermore, other operations can be added to these processes, or one or more steps can be removed from them.

[0049] For illustrative purposes, the following description is provided to aid in a better understanding of the imaging process. It is understood that this is not intended to limit the scope of this application. For those skilled in the art, certain variations, alterations, and / or modifications can be deducted from the scope of this application. These variations, alterations, and / or modifications do not depart from the scope of this application.

[0050] This specification relates to ECT detector assemblies and methods for determining the location of photon-gamma interactions in ECT detectors. ECT detector assemblies include detector micro-blocks, detector blocks, detector modules, and ECT detectors. In this specification, a detector micro-block refers to the smallest unit or basic unit used to assemble an ECT detector. In some embodiments, multiple detector micro-blocks can form a detector block, multiple detector blocks can form a detector module (e.g., a detector ring), and multiple detector modules can be assembled into a detector for an ECT device (e.g., a PET detector). For example, 64 detector micro-blocks can be arranged in an 8x8 array to form a detector block, 5 detector blocks can form a ring-shaped detector module, and 34 detector modules can form a detector. It should be understood that the number of the above-mentioned components (e.g., detector micro-blocks, detector blocks, detector modules, etc.) can be adjusted according to actual needs. Furthermore, the terms "micro-block," "block," "module," "unit," etc., used herein are used to distinguish different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, other expressions may be used instead of these terms.

[0051] In some embodiments, a detector unit may include detector units arranged side-by-side along a second direction (or from left to right). Each detector unit may include crystal elements and an array of optical sensors. The crystal elements may be arranged in columns along a first direction (or a front-to-back direction) perpendicular to the second direction, and in rows along the second direction. Each crystal element may include a first end and a second end, extending from the first end to the second end along a third direction perpendicular to the first and second directions (or from top to bottom). The optical sensor array may include optical sensors arranged along the first direction. The first end of a crystal element in each row may be optically coupled to an optical sensor in the optical sensor array, and an optical bridge may be configured at the second end of a crystal element in each column. Thus, the detector microblock may have a U-shaped structure (or an approximately inverted U-shaped structure). When photon-gamma interactions occur in the crystal elements, the output information of the optical sensors can be used to determine the depth of the photon-gamma interaction along the direction of extension of the crystal element, thereby improving imaging resolution.

[0052] In some embodiments, each crystal element in the detector microblock may have a long side along a first direction and a short side along a second direction, and the length of the long side along the first direction may be greater than the length of the short side along the second direction. Therefore, multiple detector microblocks in the detector block can be arranged in different orientations and can acquire output information with different resolutions, thereby increasing the richness of the output information and improving the accuracy of the positional information of photon-gamma interactions and the ECT image generated based on the output information.

[0053] Figure 1 This is a schematic diagram of an exemplary imaging system 100 according to some embodiments of this specification.

[0054] like Figure 1 As shown, in some embodiments, the imaging system 100 may include an imaging device 110, a network 120, one or more terminal devices 130, a processing device 140, and a storage device 150. In some embodiments, the components of the imaging system 100 may be interconnected via the network 120. Alternatively or additionally, the components of the imaging system 100 may be directly interconnected.

[0055] Imaging device 110 can scan an object and generate scan data corresponding to the object. The object may include, but is not limited to, one or more organs of a patient, one or more types of tissue, etc. In some embodiments, imaging device 110 may be a medical scanning device, such as a positron emission tomography (PET) imaging system, a single photon emission computed tomography (SPECT) imaging system, a positron emission tomography-computed tomography (PET-CT) imaging system, a positron emission tomography-magnetic resonance imaging (PET-MRI) imaging system, etc.

[0056] Imaging apparatus 110 may include a frame 111, a detector 112, a scanning area 113, and a stage 114. An object may be placed on the stage (examination bed) 114. The stage 114 can transport the object to a target location within the scanning area 113. The detector 112 can detect radiation rays (e.g., gamma photons) emitted from the object in the scanning area 113. In some embodiments, the detector 112 may include multiple detector blocks. Detector blocks may be arranged in suitable configurations, including but not limited to rings (e.g., detector rings), rectangles, triangles, arrays, etc. In some embodiments, the detector 112 may include multiple crystal elements (e.g., scintillation crystals), multiple optical sensors, and one or more optical splitters, as described elsewhere in this specification.

[0057] For ease of description, a coordinate system including the X-axis, Y-axis, and Z-axis is introduced. For example... Figure 1 As shown, the Z-axis direction can refer to the direction along which the object moves into and out of the scan area 113. The X-axis and Y-axis directions can be perpendicular to each other and form the xy plane.

[0058] In imaging applications, a tracer (e.g., a radioactive isotope) can be injected into a subject (e.g., via a patient's blood vessels). Atoms of the tracer can be incorporated into bioactive molecules. These molecules may accumulate in the patient's tissue. When a sufficient amount of molecules is estimated to have accumulated in the tissue (e.g., within one hour), the patient can be positioned on workbench 114. The radioactive isotope can undergo positron emission decay (i.e., beta decay) and emit a positron. The positron can interact with electrons within the tissue (the interaction between a positron and an electron is called annihilation). Each pair of electron-positron annihilation produces a pair of annihilation photons moving in approximately opposite directions. When the annihilation photons strike a crystal element of detector 112, they can be absorbed by the crystal element, producing optical photons (e.g., visible light photons). These optical photons can then be detected by one or more optical sensors. The interaction between the annihilation photons and the crystal element that produces the burst of optical photons may be referred to herein as photon gamma interaction. The depth of photon-gamma interaction along the extension direction of the crystal element where the photon-gamma interaction occurs can be called the depth of interaction (DOI).

[0059] Processing device 140 can generate images based on information associated with annihilated photons. For example, processing device 140 can determine the time-of-flight (TOF) information associated with each pair of annihilated photons. Processing device 140 can also determine DOI information based on the output information of the optical sensor in detector 112. Processing device 140 can also determine the location where annihilation occurs based on the time information and DOI information. After determining the location of annihilation, processing device 140 can generate a projection image (also known as a sinogram) based on the location of annihilation. Processing device 140 can reconstruct an image based on the projection image and reconstruction techniques such as filtered back projection (FBP). The reconstructed image can indicate tissue containing a large number of bioactive molecules (also known as tracer molecules) containing tracers. In some embodiments, the number of tracer molecules in a region can be correlated with the biological function of the tissue in that region. For example, if fluorodeoxyglucose (FDG) is used as a tracer in a PET scan, the number of tracer molecules in a region can be proportional to the rate of glucose metabolism in that region. Since tumors typically consume large amounts of glucose, regions with a high concentration of tracer molecules can be identified as tumor tissue in reconstructed images.

[0060] Network 120 may include any suitable network capable of facilitating information and / or data exchange within imaging system 100. In some embodiments, one or more components of imaging system 100 (e.g., imaging device 110, terminal device 130, processing device 140, storage device 150) may exchange information and / or data with one or more other components within imaging system 100 via network 120. For example, processing device 140 may acquire image data (e.g., TOF information, energy information, DOI information, etc.) from imaging device 110 via network 120. Network 120 may include public networks (e.g., the Internet), private networks (e.g., local area networks (LANs)), wired networks, wireless networks (e.g., 802.11 networks, Wi-Fi networks), Frame Relay networks, virtual private networks (VPNs), satellite networks, telephone networks, routers, hubs, switches, fiber optic networks, telecommunications networks, intranets, wireless local area networks (WLANs), metropolitan area networks (MANs), public switched telephone networks (PSTNs), Bluetooth networks, ZigBee networks, near field communication (NFC) networks, and any combination thereof. 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 which one or more components of imaging system 100 may connect to network 120 to exchange data and / or information.

[0061] Terminal device 130 can communicate and / or connect to imaging device 110, processing device 140, and / or storage device 150. For example, a user can interact with imaging device 110 through terminal device 130 to control one or more components of imaging device 110. In some embodiments, terminal device 130 may include mobile device 130-1, tablet computer 130-2, laptop computer 130-3, etc., or any combination thereof. For example, mobile device 130-1 may include a mobile control handle, personal digital assistant (PDA), smartphone, etc., or any combination thereof. In some embodiments, terminal device 130 may be part of imaging device 110 or processing device 140.

[0062] Processing device 140 can process data and / or information obtained from imaging device 110, one or more terminal devices 130, storage device 150, or other components of imaging system 100. For example, processing device 140 can process image data (e.g., output information, TOF information, energy information, DOI information, etc.) and reconstruct images based on the image data. In some embodiments, processing device 140 can be a single server or a group of servers. The server group can be centralized or distributed. In some embodiments, processing device 140 can be local or remote. For example, processing device 140 can access information and / or data from imaging device 110, one or more terminal devices 130, and / or storage device 150 via network 120. As another example, processing device 140 can be directly connected to imaging device 110, one or more terminal devices 130, and / or storage device 150 to access information and / or data. In some embodiments, processing device 140 can be implemented on a cloud platform. For example, the cloud platform can include private cloud, public cloud, hybrid cloud, community cloud, distributed cloud, inter-cloud cloud, multi-cloud, etc., or any combination thereof. In some embodiments, the processing device 140 or a portion thereof may be integrated into the imaging device 110.

[0063] Processing device 140 may include a processor, a storage module, input / output (I / O) ports, and communication ports. The processor can execute computer instructions (e.g., program code) and perform the functions of processing device 140 as described herein. Computer instructions may include, for example, routines, programs, objects, components, data structures, procedures, modules, functions, etc., that perform specific functions described herein. The storage module may store data / information obtained from imaging device 110, one or more terminal devices 130, storage device 150, and / or any other component of imaging system 100. In some embodiments, the storage module may include mass storage, removable storage, volatile read-write storage, read-only storage (ROM), etc., or any combination thereof. I / O may input and / or output signals, data, information, etc. In some embodiments, I / O may enable user interaction with processing device 140. In some embodiments, I / O may include input devices and output devices. Exemplary input devices may include a keyboard, mouse, touchscreen, microphone, etc., or any combination thereof. Exemplary output devices may include a display device, speaker, printer, projector, etc., or any combination thereof. 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 device 140 and the imaging device 110, one or more terminal devices 130, and / or the storage device 150. This connection can be a wired connection, a wireless connection, any other communication connection capable of data transmission and / or reception, and / or any combination of these connections.

[0064] Storage device 150 may store data, instructions, and / or any other information. In some embodiments, storage device 150 may store data acquired from imaging device 110, one or more terminal devices 130, and / or processing device 140. In some embodiments, storage device 150 may store data and / or instructions used by processing device 140 to perform or use in order to accomplish the exemplary methods described herein. In some embodiments, storage device 150 may store image data acquired from imaging device 110 (e.g., output information, TOF information, energy information, DOI information, etc.). In some embodiments, storage device 150 may include mass storage, removable storage, volatile read-write storage, read-only storage (ROM), etc., or any combination thereof. In some embodiments, storage device 150 may be connected to network 120 to communicate with one or more other components in imaging system 100 (e.g., imaging device 110, one or more terminal devices 130, and processing device 140). In some embodiments, storage device 150 may be part of processing device 140.

[0065] 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. Various changes and modifications can be made by those skilled in the art based on the content of this specification. Features, structures, methods, and other features of the exemplary embodiments described herein can be combined in various ways to obtain other and / or alternative exemplary embodiments. For example, the imaging system 100 may also include other components such as a patient positioning unit, data acquisition electronics, a power supply, and other devices or units. However, these changes and modifications will not depart from the scope of this specification.

[0066] Figure 2 This is a schematic diagram of an exemplary crystal assembly according to some embodiments of this specification.

[0067] In some embodiments, the detector (e.g., detector 112) may include one or more crystal groups 200A. The crystal group 200A may be configured to detect annihilation photons generated by annihilation events during scanning of an object.

[0068] like Figure 2 As shown, the crystal group 200A may include a crystal array 210 and an optical sensor array 220 optically coupled to the crystal array 210 (in Figure 2 The dark region shown), one or more first optical splitters 212, and one or more second optical splitters 213. The crystal array 210 may include a plurality of crystal elements 211 (e.g., crystal elements 211a and 211b), each of which may be configured to receive annihilation photons (e.g., gamma photons) from the object. For simplicity and illustration purposes, as shown... Figure 2 The crystal array 210 shown includes only two crystal elements 211, and this is not intended to be limiting. The crystal group 200A may include any number or count of crystal elements 211. For example, the crystal array 210 may include three or more crystal elements 211. The optical sensor array 220 may include a plurality of optical sensors 221 configured to detect optical photons emitted from a first end of the crystal element 211.

[0069] The crystal elements 211 of the crystal array 210 can be arranged along a first direction to form a structure such that... Figure 2The crystal element array is shown. Correspondingly, a crystal group can be referred to as a crystal element array. Each crystal element 211 may include a first end S1 (e.g., a bottom end) and a second end S2 (e.g., a top end), extending from the first end S1 to the second end S2 along a third direction (e.g., from bottom to top). The first end S1 of crystal element 211 refers to the end through which optical photons exit crystal element 211 and enter optical sensor 221. The second end S2 of crystal element 211 refers to the end through which radiation (e.g., gamma rays caused by annihilation events) enters crystal element 211. The second end S2 of crystal element 211 may be closer to the scanned object than the first end S1 of crystal element 211. In some embodiments, the second end S2 of crystal element 211 may be coated with a light-reflecting material to completely or substantially completely prevent optical photons in crystal element 211 from escaping from the second end S2 of crystal element 211.

[0070] Crystal element 211 can be made of any material capable of absorbing radiation rays and emitting a portion of the absorbed radiation rays as light. For example, crystal element 211 can be made of, for instance, bismuth germanium oxide (BGO), lutetium oxysilicate (LSO), lutetium yttrium oxysilicate (LYSO), lutetium gadolinium oxysilicate (LGSO), gadolinium oxysilicate (GSO), barium fluoride, sodium iodide, cesium iodide, lead tungstate, yttrium aluminate, lanthanum chloride, perovskite lutetium aluminum, lutetium disilicate, lutetium aluminate, lutetium iodide, thallium bromide, etc., or any combination thereof. Different crystal elements 211 can be made of the same material or different materials.

[0071] The sizes and / or shapes of the different crystal elements 211 can be the same or different. For example, the crystal elements 211 of the crystal array 210 can have uniform sizes and shapes. As another example, the different crystal elements 211 can have different lengths. The length of a crystal element 211 can refer to the dimension of the crystal element 211 along its extension direction (i.e., the third direction). In some embodiments, the size and / or shape of the crystal element 211 can vary according to one or more conditions (including, for example, the image resolution of the detector, the size of the detector, etc., or any combination thereof). By way of example only, to obtain different spatial resolutions, the crystal elements 211 can have different lengths in a first direction and a second direction.

[0072] In some embodiments, a single end of each crystal element 211 of the crystal array 210 may be optically coupled to an optical sensor 221. Each of the plurality of optical sensors 221 may be optically coupled to one or more crystal elements 211 of the crystal array 210. Different optical sensors 221 may be coupled to the same number (or count) or different number (or count) of crystal elements 211. When an optical sensor 221 is coupled to a plurality of crystal elements 211, the optical sensor 221 may determine output information corresponding to each of the plurality of crystal elements 211. The output information may reflect the energy of the optical photons excited by photon-gamma interactions in the corresponding crystal element 211 and detected by the optical sensor 211.

[0073] Optical sensor 221 can be coupled to the corresponding crystal element 211 in any suitable manner. For example, optical sensor 221 can directly contact the corresponding crystal element 211. Alternatively, optical sensor 221 can be fixed to the corresponding crystal element 211 by one or more adhesive materials (e.g., light-transmitting adhesive). Yet another example is that optical sensor 221 can be coupled to one end of the corresponding crystal element 211 by a light-transmitting material (e.g., a piece of glass). In some embodiments, one or more optical sensors 221 can be optically coupled to crystal element 211 (e.g., crystal element 211a or 211b) to receive photons from one end (e.g., the first end S1) of crystal element 211. A detector that uses one or more optical sensors 221 to detect photons from one end of each crystal element 211 can be referred to as a detector with a single-end readout structure.

[0074] In some embodiments, the optical sensor 221 may include a phototube, a photomultiplier tube (PMT), a photodiode, an active pixel sensor, a radiation thermal meter, a gas ionization detector, a photoresistor, a phototransistor, an avalanche photodiode (APD), a single-photon avalanche photodiode (SPAD), a silicon photomultiplier (SiPM), a digital silicon photomultiplier (DSiPM), or any combination thereof. Different optical sensors 221 may be of the same type or different types.

[0075] In some embodiments, light sharing between two adjacent (or neighboring) crystal elements 211 belonging to the same crystal group 200A may be permitted, while light sharing between two adjacent crystal groups may be restricted or substantially restricted to facilitate the determination of the location of photon-gamma interactions. If there are no other crystal elements between two crystal elements 211, the two crystal elements 211 may be considered adjacent or neighboring to each other. In some embodiments, two adjacent or neighboring crystal elements may be spaced apart by a void space, an article other than a crystal element (e.g., a film, a coating, a layer of material different from the material of any crystal element of the adjacent crystal element, etc.), or any combination thereof. By way of example only, a space may exist between two adjacent crystal elements of the same crystal group, a portion of which may be filled with an optical splitter (e.g., a second optical splitter 213 described elsewhere in this specification), and a portion of which may be empty. As another example, a space may exist between two adjacent crystal elements of the same crystal group, a portion of which may be filled with an optical splitter (e.g., a second optical splitter described elsewhere in this specification), and another portion of which may be filled with an optical propagation medium. The optical propagation medium can be any material that allows light to pass through (e.g., glass, anti-reflective materials), which enables light sharing between two adjacent crystal elements in the same crystal group. For example... Figure 2 As shown, a portion of the space between crystals 211a and 211b is filled with an optical propagation medium 214, through which photons can propagate between crystals 211a and 211b. The optical propagation medium 214 can be configured between each pair of adjacent crystal elements in the crystal group 200A (or crystal element column), and the optical propagation medium 214 can extend from the second end S2 of the corresponding pair of adjacent crystal elements to the second optical separator 213 between the corresponding pair of adjacent crystal elements.

[0076] In some embodiments, the widths of the second optical splitter 213 and the optical propagation medium 214 can be determined according to actual usage requirements. Taking the optical propagation medium 214 as an example, the width of the optical propagation medium 214 can refer to its dimension along a first direction. For example, the width of the optical propagation medium 214 can be determined based on the length of the crystal element. For example, the width of the optical propagation medium 214 can be positively correlated with the length of the crystal element. By way of example only, the width of the optical propagation medium 214 can be within a certain range, such as 1-5 mm, 1.5-4.5 mm, 2-4 mm, 2.5-3.5 mm, etc. The length of the optical propagation medium 214 can be determined based on the second optical splitter 213. The length of the optical propagation medium 214 can refer to its length along a third direction. For example, in the same crystal group, the sum of the length of the optical propagation medium 214 and the length of the second optical splitter 213 can be equal to the length of any crystal element in the crystal group.

[0077] If there are no other crystal groups between two crystal groups, then the two crystal groups can be considered adjacent or neighboring to each other. In some embodiments, two adjacent or neighboring crystal groups may be separated by a gap space, an article other than crystal elements (e.g., a film, a coating, a layer of material different from the material of any crystal element of the adjacent adjacent crystal group, etc.), or any combination thereof. By way of example only, there may be a space between two adjacent crystal groups, a portion of which may be filled with an optical separator (e.g., a first optical separator described elsewhere in this specification), and a portion of which may be empty. As another example, the space between two adjacent crystal groups may be substantially completely filled with an optical separator (e.g., a first optical separator described elsewhere in this specification).

[0078] To control light transmission between two adjacent crystal elements 211 or two adjacent crystal groups, multiple optical splitters can be used in the crystal group 200A. The optical splitters may include reflective films, reflective foils, reflective coatings (e.g., white reflective coatings), or any other material that can block or substantially block light transmission. Figure 2 The shaded areas shown represent one or more optical splitters configured to block or partially block light transmission between crystal elements 211. For example, a first optical splitter 212 may substantially or completely cover the side surface of crystal element 211a to prevent optical photons in crystal group 200A from traveling from the side facing the adjacent crystal group to the adjacent crystal group (…). Figure 2 (Not shown in the image). The first length of the first optical splitter 212 may be equal to the length of the crystal element 211a.

[0079] The second optical splitter 213 can be located between each pair of adjacent crystal elements in the crystal group (or crystal element column). The second optical splitter 213 can extend from the first end S1 of the corresponding pair of adjacent crystal elements but not to the second end S2 of the corresponding pair of adjacent crystal elements, to partially block optical photon transmission between the corresponding pair of adjacent crystal elements. For example, the second optical splitter 213 can be located between crystal elements 211a and 211b. The second optical splitter 213 can extend from the first end S1 of crystal element 211a or 211b along a third direction. The second length of the second optical splitter 213 can be less than the length of crystal element 211a or 211b, such that the second optical splitter 213 can partially block optical photon transmission between crystal elements 211a and 211b. The first length of the first optical splitter 212 can be greater than the second length of the second optical splitter 213. The length of the optical splitter can refer to the length of the optical splitter along the extension direction of crystal element 211 (i.e., the third direction).

[0080] In some embodiments, the length of the second optical splitter 213 may be equal to or greater than half the length of at least one of the crystal elements 211a and 211b. In some embodiments, the length of the second optical splitter 213 may be equal to N% of the length of either the crystal element 211a or 211b. N may have any suitable positive value (N is less than 100). In some embodiments, N may be within a range, such as 30 to 90, 50 to 85, etc. For example, N may be 30, 40, 50, 60, 70, 80, 85, or 90. N may be a parameter used to determine the location of photon-gamma interactions in the crystal group 200A. In some embodiments, N may be a default parameter stored in a storage device (e.g., storage device 150). Alternatively, N may be manually set or determined by one or more components of the imaging system 100, depending on the circumstances. In some embodiments, the material of the second optical splitter 213 may be the same as or different from the material of the first optical splitter 212.

[0081] It should be noted that, Figure 2 The examples shown are provided for illustrative purposes only and are not intended to limit the scope of this specification. Various changes and modifications can be made based on the description herein by those skilled in the art. However, these changes and modifications do not depart from the scope of this specification. In some embodiments, the crystal array 210 may include any suitable number or count of crystal elements 211. For example, the crystal array 210 may include an even number (e.g., 2, 4, 6, 8, or 12) of crystal elements 211. The crystal elements 211 may be arranged in any suitable manner. For example, the crystal elements 211 of the crystal array 210 may be arranged along a second direction to form rows of crystal elements.

[0082] Figure 3A and Figure 3B This is a schematic diagram of exemplary photonic gamma interactions occurring in an exemplary crystal group according to some embodiments of this specification.

[0083] Photonic gamma interactions occurring in crystal group 200A can excite one or more optical photons, which can be detected by corresponding optical sensors 221a and / or 221b as described elsewhere in this specification. The number or count of optical photons detected by optical sensor 221a or optical sensor 221b can be correlated with the location of the photonic gamma interactions in crystal group 200A. For example, as Figure 3A As shown, photon-gamma interaction 1 occurs at the top of the second optical separator 213 (in Figure 3AThe location is denoted as T) closer to (or lower than) the first end S1. Optical photons generated by photon-gamma interaction 1 can be blocked or substantially blocked by the second optical separator 213, preventing them from traveling into the crystal element 211b. Therefore, all or almost all optical photons excited by photon-gamma interaction 1 can be detected by optical sensor 221a. This is only an example, such as... Figure 3A As shown, photon-gamma interaction 1 can generate multiple optical photons. Some of these optical photons can travel directly along photon travel paths 1a and 1b to optical sensor 221a and be detected by it. Other optical photons can travel along photon travel path 1c, be reflected by the second optical splitter 213, and then be detected by optical sensor 221a.

[0084] For example, such as Figure 3B As shown, photon-gamma interaction 2 occurs at the top of the second optical separator 213 (at... Figure 3B The location is denoted as T) further away from the first end S1 (or higher). Optical photons excited by the photon-gamma interaction 2 can be partially blocked from traveling into the crystal element 211b by the second optical separator 213. Therefore, the optical photons can be detected by both optical sensors 221a and 221b. By way of example only, the photon-gamma interaction 2 can generate multiple optical photons. Some of the multiple optical photons can be directly detected by optical sensor 221a along photon travel paths 2a and 2b, while some optical photons can travel into the crystal element 211b along photon travel path 2c and be detected by optical sensor 221b.

[0085] Figure 4A This is a schematic diagram of an exemplary crystal assembly 200B according to some embodiments of this specification.

[0086] The crystal group (or crystal element array) 200B can be similar to Figures 2 to 3BThe described crystal group 200A, except that the second ends S2 of crystal elements 211a and 211b can be integrated into a single end. In some embodiments, crystal group 200B can be manufactured by partially cutting a single crystal block into crystal elements 211a and 211b. The cut can extend from the first end S1 of the crystal block to its second end S2, and the cut can extend to a depth not reaching the second end S2. That is, the second ends S2 of crystal elements 211a and 211b in each crystal group 200B (or crystal element column) can be integrated into a single piece as an optical bridge. The second optical splitter 213 can be made by filling the cut grooves of the crystal block with one or more reflective materials. In this case, light transmission between crystal elements 211a and 211b can be allowed in the uncut portion near the second end S2, while light transmission between crystal elements 211a and 211b can be blocked in the cut portion near the first end S1. The first optical splitter 212 can be formed by coating other side surfaces of crystal elements 211a and / or 211b with a light-reflecting material. That is, the light-reflecting material can be filled between crystal group 200B and adjacent crystal groups. In this case, it can prevent crystal group 200B from interacting with adjacent crystal groups ( Figure 4A Light transmission between (not shown in the image).

[0087] In some embodiments, the location of photonic gamma interaction 3 in crystal group 200B can be determined based on the output information of optical sensors 221a and 221b. The output information can reflect the energy of optical photons excited by photonic gamma interaction 3 and detected by optical sensors 221a and / or photon sensors 221b. In some embodiments, the depth of photonic gamma interaction 3 in the crystal element (also referred to as the target crystal element) and / or the target crystal element can be determined based on the output information.

[0088] Figure 4B This is a schematic diagram of an exemplary crystal assembly 200C according to some embodiments of this specification.

[0089] The crystal group (or crystal element array) 200C can be similar to Figures 2 to 3B The described crystal group 200A differs in that the length of the second optical splitter 213 is equal to at least one of crystal elements 211a and 211b (i.e., the second optical splitter 213 covers either crystal element 211a or crystal element 211b), and light transmission between crystal elements 211a and 211b in the crystal group 200C is achieved through an optical transmission medium 410 mounted on the second end S2. Figure 4BAs shown, the crystal assembly 200C may include crystal elements (e.g., crystal elements 211a and 211b) and optical sensors (e.g., optical sensors 221a and 221b) optically coupled to the crystal elements. Figure 4B The dark area shown), optical splitters (e.g., first optical splitter 212, second optical splitter 213), and optical bridge.

[0090] The optical bridge may include an optical propagation medium 410 covering the second ends of crystal elements 211a and 211b in the crystal group 200C. Each side (e.g., side 410a and side 410b) and the surface 410c of the optical propagation medium 410 away from the second end S2 of the optical propagation medium 410 facing the adjacent crystal group 200C may be coated with a reflective material to completely or substantially completely prevent optical photons in the crystal group 200C from leaving the optical propagation medium 410 from its sides. The optical propagation medium 410 may be made of any material that allows light to pass through (e.g., glass, scintillation crystal). Optical photons excited by photon-gamma interactions occurring in one crystal element of the crystal group 200C may travel to the optical propagation medium 410, be reflected once or multiple times by the sides of the optical propagation medium 410, and then travel to another crystal element of the crystal group 200C. Figure 4B As shown, optical photons generated by the photon-gamma interaction 4 in the crystal element 211a can travel through the light transmission medium 410 (e.g., along the photon movement path 4b) into the crystal element 211b.

[0091] The location of the photonic gamma interaction occurring in the crystal group 200C can be determined based on the output information of optical sensors 221a and 221b optically coupled to the crystal group 200C. In some embodiments, the location of the photonic gamma interaction can be determined based on the energy detected by optical sensors 221a and 221b. For example, as... Figure 4B As shown, the photon-gamma interaction 4 occurs at a position closer to the second end S2 than the first end S1 of the crystal element 211a. A portion of the optical photons generated by the photon-gamma interaction 4 can travel directly to the optical sensor 221a along photon travel paths 4a and 4c, and be detected by the optical sensor 221a; a portion of the optical photons can travel along photon travel path 4b through the light transmission medium 410 to the crystal element 211b, and be detected by the optical sensor 221b.

[0092] In some embodiments, the location of photonic gamma interaction in crystal group 200C can be determined based on the time it takes for photons generated by the photonic gamma interaction to be received by optical sensors 221a and 221b. Taking photonic gamma interaction 4 as an example, the time difference between a first time point when optical sensor 221a receives a photon (e.g., a photon traveling along photon travel path 4a) and a second time point when optical sensor 221b receives a photon (e.g., a photon traveling along photon travel path 4b) can be determined. The DOI of photonic gamma interaction 4 can be estimated based on the time difference and the speed of light. A shorter time difference can indicate that photonic gamma interaction 4 occurs at a location closer to the second end of crystal element 211a.

[0093] As described above, crystal group 200, crystal group 200B, and crystal group 200C all have a U-shaped (inverted U-shaped) structure, which includes a U-shaped (inverted U-shaped) optical path. A U-shaped optical path refers to a path with a U-shape along which photons can propagate. In this specification, the orientation of the U-shaped optical path is not limited; for example, for each crystal group 200, crystal group 200B, and crystal group 200C, the U-shaped optical path is inverted. Light transmission can be achieved near the second end S2 of the crystal element (i.e., the lower part corresponding to the U-shape), while light transmission cannot be achieved near the first end S1 of the crystal element (i.e., the upper part corresponding to the U-shape or the lower part of the inverted U-shape). In this specification, a crystal group with a U-shaped optical path can be referred to as a U-shaped crystal group. The portion of the U-shaped crystal group that allows light to pass through can be referred to as an optical bridge or an optical window. For example, the uncut ends of crystal elements 211a and 211b in crystal group 200B can be considered as optical bridges, and the optical transmission medium 410 covering the second ends S2 of crystal elements 211a and 211b in crystal group 200C can be considered as an optical bridge. In other embodiments, the optical propagation medium 214 in crystal group 200A can be considered as an optical bridge. It should be understood that a U-shaped crystal group can include more than two crystal elements, as long as the second end of the crystal element can realize optical transmission and the first end cannot realize optical transmission.

[0094] The special structure of the U-shaped crystal set can be used to determine DOI information, that is, to determine the depth of photon-gamma interaction in the extension direction of the crystal element. In some embodiments, an ECT detector assembly (e.g., a U-shaped detector, detector unit, etc.) capable of DOI calculation can be constructed based on the U-shaped crystal set. For further description of the ECT detector assembly, please refer to other parts of this specification (e.g., Figures 5A-6F (and related descriptions).

[0095] Figure 5AThis is a schematic diagram of an exemplary detector microblock 300 according to some embodiments of this specification. Figure 5B This is a schematic diagram of a rear view of an exemplary detector microblock 300 shown according to some embodiments of this specification. Figure 5C This is a schematic diagram of a right view of an exemplary detector microblock 300 shown according to some embodiments of this specification. Figure 5D This is a schematic top view of an exemplary detector microblock 300 shown according to some embodiments of this specification.

[0096] Detector microarray 300 can be configured to detect annihilation photons generated by annihilation events during an ECT scan of an object. In some embodiments, detector microarray 300 may include one or more detector elements. Detector elements may be arranged side-by-side along a second direction. Each of the one or more detector elements may include one or more U-shaped crystal groups (e.g., crystal group 200A, crystal group 200B, crystal group 200C). Similar to U-shaped crystal groups, U-shaped detectors may also have a U-shaped structure and include a U-shaped optical path. Therefore, a detector element may also be referred to as a U-shaped detector element.

[0097] like Figures 5A-5D As shown, the detector micro-block 300 may include a first detector unit 301 and a second detector unit 302. The first detector unit 301 may include a crystal array 310, an optical sensor array 320 optically coupled to the crystal array, one or more optical splitters, and an optical bridge. The crystal array 310 may include a plurality of crystal elements 311 (e.g., crystal elements 311a, 311b, 311c, and 311d), which may be arranged in crystal element columns (e.g., crystal element columns 350a and 350b) (also referred to as crystal groups) along a first direction perpendicular to the second direction, and in crystal element rows along the second direction. For example, two crystal elements may be arranged in each crystal element column of the detector unit along the first direction, and two crystal elements may be arranged in each crystal element row of the detector unit along the second direction. Each of the plurality of crystal elements 311 may have a first end S1 (e.g., a bottom end) and a second end S2 (e.g., a top end), and extend from the first end S1 along a third direction perpendicular to the first and second directions to the second end S2. The optical sensor array 320 may include a plurality of optical sensors (e.g., optical sensors 321a and 321b), which may be arranged in an optical sensor column along a first direction.

[0098] Similarly, the second detector unit 302 may include a crystal array 330, an optical sensor array 340 optically coupled to the crystal array, and one or more optical splitters. The crystal array 330 may include multiple crystal elements 331 (e.g., crystal elements 331a, 331b, 331c, and 331d), and the optical sensor array 340 may include multiple optical sensors (e.g., optical sensors 341a and 341b). An optical bridge may be configured at the second end of a crystal element in each crystal element column.

[0099] Each crystal element (e.g., each of crystal elements 311a, 311b, 311c, 311d, 331a, 331b, 331c, and 331d) can be configured to receive annihilation photons from the object. Figure 5A As shown, the crystal elements 311 of the crystal array 310 and the crystal elements 331 of the crystal array 330 in the detector micro-block 300 can form two rows of crystals arranged parallel to the second direction and four columns of crystal elements arranged parallel to the first direction. In some embodiments, the second direction can be orthogonal or approximately orthogonal to the first direction. In some embodiments, both the first and second directions can be orthogonal or approximately orthogonal to the extending direction of the crystal element (i.e., the third direction).

[0100] Each crystal element of crystal array 310 and crystal array 330 can be similar to Figures 2 to 4BThe crystal element described herein. In some embodiments, each crystal element may have a long side along a first direction and a short side along a second direction. In this specification, the long side refers to the side of the crystal element parallel to the first direction (i.e., the arrangement direction of the crystal elements in the crystal group), and the short side refers to the side parallel to the second direction. For example, the length of the long side along the first direction may be determined based on the length of the optical sensor 221. In another embodiment, the length of the long side along the first direction may be within a first range, for example, 1-5 mm, 2-4.5 mm, 2.5-4 mm, 3-4 mm, etc. The length of the short side along the second direction may be within a second range, for example, 1-5 mm, 1.5-4 mm, 2-3 mm, etc. In some embodiments, the length of the long side of the crystal element may be greater than the length of the short side of the crystal element. For example, the ratio of the length of the long side along the first direction to the length of the short side along the second direction may be greater than 1 and less than 5. For example, the ratio of the length of the long side along the first direction to the length of the short side along the second direction can be 1.2, 1.5, 1.8, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, etc. Since the area of ​​the crystal element (i.e., the product of the length of the long side and the length of the short side) is positively correlated with the temporal resolution of the crystal element, the length of the short side of the crystal element can be greater than a preset length threshold to ensure that the temporal resolution meets practical requirements. Furthermore, as the length of the short side of the crystal element decreases, the number of crystal elements in the detector micro-block 300 may increase, and the number of optical splitters in the detector micro-block 300 may increase, thereby reducing the sensitivity of the detector micro-block 300. Therefore, the preset length threshold of the short side can be determined by considering the temporal resolution and sensitivity of the detector micro-block 300. As an example only, the length of the long side along the first direction can be 4.3 mm, and the length of the short side along the second direction can be 2.1 mm. Alternatively, the length of the long side along the first direction can be 3.0 mm, and the length of the short side along the second direction can be 1.5 mm. Since the length of the longer side along the first direction is not equal to the length of the shorter side along the second direction, the resolution of the crystal element in the first direction may differ from the resolution in the second direction. Therefore, by arranging the detector micro-blocks 300 in different directions, output information with different resolutions can be acquired.

[0101] In some embodiments, in each detector unit, the crystal elements can form multiple U-shaped crystal groups along a first direction. Taking the first detector unit 301 as an example, the first detector unit 301 may include four crystal elements 311a, 311b, 311c, and 311d, forming a 2×2 crystal array. Crystal elements 311a and 311c can form a crystal element column (or crystal group) 350a, and crystal elements 311b and 311d can form a crystal element column (or crystal group) 350b. It should be noted that... Figure 5AProvided for illustrative purposes only and not intended to limit the scope of this specification. Each crystal element column 350 may include any number of crystal elements 311.

[0102] Crystal element column 350 can be similar to Figure 2 Crystal group 200A in Figure 4A Crystal group 200B or Figure 4B The crystal group 200C is described above. Light transmission between and within the crystal group can be controlled by applying one or more first optical splitters 312 and one or more second optical splitters 313. The first optical splitter 312 can be similar to the first optical splitter 212, and the second optical splitter 313 can be similar to the second optical splitter 213; further details are omitted here. For example, see... Figure 5C A second optical splitter 313 is disposed between a pair of adjacent crystal elements 311a and 311c in crystal element column 350a. This splitter extends from a first end (e.g., bottom end) S1 of the corresponding pair of adjacent crystal elements 311a and 311c, but does not reach the second end (e.g., top end) S2 of the corresponding pair of adjacent crystal elements 311a and 311c, so as to partially block optical photon transmission between the corresponding pair of adjacent crystal elements 311a and 311c. An optical propagation medium 316 can serve as an optical bridge and is disposed between a pair of adjacent crystal elements 311a and 311c in crystal element column 350a. The optical propagation medium 316 extends from the second end S2 of the corresponding pair of adjacent crystal elements 311a and 311c to the second optical splitter 313 between the corresponding pair of adjacent crystal elements 311a and 311c. In other words, in the crystal element row 350a, the sum of the length of the optical propagation medium 316 and the length of the second optical splitter 313 can be equal to the length of either crystal element 311a or crystal element 311c in the crystal element row 350a. By using the second optical splitter 313 and the optical propagation medium 316, optical sharing between crystal elements 311a and 311c at the second end in the crystal group 350a can be achieved. Alternatively, the first optical splitter 312 can be configured between adjacent crystal elements of adjacent detector micro-blocks.

[0103] In some embodiments, propagation between adjacent crystal groups can be controlled by applying a third optical splitter 314 in each detector unit. The third optical splitter 314 can be configured between each pair of adjacent crystal element columns in the detector unit, extending from a first end of a crystal element in a corresponding pair of adjacent crystal element columns to a second end of a crystal element in a corresponding pair of crystal element columns, to block optical photon transmission between corresponding pairs of crystal element columns. Figure 5A and 5BAs shown, the third optical splitter 314 can be configured between adjacent crystal element columns 350a and 350b in the detector unit 301, and the third optical splitter 314 extends from the first end S1 of crystal elements 311a, 311b, 311c and 311d in the corresponding pair of adjacent crystal element columns 350a and 350b to the second end S2 of crystal elements 311a, 311b, 311c and 311d in the corresponding pair of adjacent crystal element columns 350a and 350b, for blocking the transmission of optical photons between the corresponding pair of crystal element columns 350a and 350b.

[0104] The length of each third optical splitter 314 can be equal to or less than the length of at least one crystal element on either side of it. Different third optical splitters 314 can have the same or different lengths. This is just an example, such as... Figure 5B As shown, the length of the third optical splitter 314 can be equal to the lengths of crystal elements 311a and 311b, to block or substantially block light transmission between crystal element columns 350a and 350b. That is, it can block light transmission between two crystal element columns of the same detector unit.

[0105] In some embodiments, in the detector micro-block 300, optical transmission between detector elements can be controlled by applying a fourth optical splitter 315 and a second optical bridge 317. The fourth optical splitter 315 can be located between each pair of adjacent detector elements in the detector micro-block and extends from the second end S2 of the crystal element in the corresponding pair of adjacent detector elements, but does not reach the first end S1 of the crystal element in the corresponding pair of adjacent detector elements, to partially block optical photon transmission between the corresponding pair of adjacent detector elements. The second optical bridge 317 can be located between each pair of adjacent detector elements in the detector micro-block and extends from the first end S1 of the crystal element in the corresponding pair of adjacent detector elements, but does not reach the second end S2 of the crystal element in the corresponding pair of adjacent detector elements, to allow optical photon transmission between the corresponding pair of adjacent detector elements.

[0106] like Figure 5A and 5B As shown, the fourth optical splitter 315 and the second optical bridge 317 can be located between adjacent first detector units 301 and second detector units 302. For example, the fourth optical splitter 315 and the second optical bridge 317 can be used to control the light transmission between the first detector unit 301 and the second detector unit 302. The length of the fourth optical splitter 315 can be equal to or less than the length of the crystal elements on both sides of it. The length of the fourth optical splitter 315 in different detector micro-blocks 300 can be the same or different. This is just an example. Figure 5A and Figure 5BAs shown, a portion of the space between the first detector unit 301 and the second detector unit 302 (e.g., between crystal element 311d and crystal element 331c) is filled with a fourth optical splitter 315 to block optical photon transmission between the crystal elements at the second end S2. The remaining space is filled with a second optical bridge 317 to allow optical photon transmission between the first detector unit 301 and the second detector unit 302 at the first end S1. In some embodiments, in the detector microblock 300, the sum of the length of the second optical bridge 317 and the length of the fourth optical splitter 315 can be equal to the length of the crystal element in the detector microblock 300.

[0107] In some embodiments, the optical sensor array of each detector unit may include two optical sensors. Taking the first detector unit 301 as an example, its optical sensor array 320 may include two optical sensors 321 (e.g., optical sensor 321a and optical sensor 321b) arranged along a first direction. Each optical sensor 321 may be optically coupled to one or more crystal elements of the crystal array 310. For example, the first end of a crystal element in each row of crystal elements may be optically coupled to one optical sensor of the optical sensor array. This is merely an example. Figures 5A-5C As shown, optical sensor 321a can completely cover the first end S1 of crystal elements 311a and 311b in the same row; optical sensor 321b can completely cover the first end S1 of crystal elements 311c and 311d in the same row; optical sensor 341a can completely cover the first end S1 of crystal elements 331a and 331b in the same row; and optical sensor 341b can completely cover the first end S1 of crystal elements 331c and 331d in the same row. The optical sensors are located at the ends of the crystal elements and are configured to detect optical photons from a single end of the corresponding crystal element. The optical coupling between the optical sensor and its corresponding crystal element can be any suitable manner as described elsewhere in this specification (e.g., ...). Figure 2 (and its description).

[0108] It should be noted that, Figures 5A-5D The fact that each optical sensor corresponds to two crystal elements along the second direction (i.e., the coupling ratio of the optical sensor and the crystal element is 1:2) is provided for illustrative purposes only and is not intended to limit the scope of this specification. For example, an optical sensor may correspond to one, three, four or more crystal elements depending on its crystal position identification capability and / or light collection efficiency.

[0109] By applying the specially designed structure of the detector micro-block 300, the location information of the photon-gamma interaction occurring within the detector micro-block 300 can be determined based on the output information of multiple optical sensors. For example, as Figure 5C As shown, the photon-gamma interaction occurs closer to the second end S2 of the crystal element 311c than to the first end S1. A portion of the optical photons generated by the photon-gamma interaction 5 can travel directly to the optical sensor 321b along photon movement paths 5a and 5b, and be detected by the optical sensor 321b. A portion of the optical photons can enter the crystal element 311a along photon movement path 5c through the optical propagation medium 316, and be detected by the optical sensor 321a. The position information of the photon-gamma interaction 5 in the crystal element column 350a (i.e., the target crystal element column) of the first detector unit 301 can be determined based on the output information of the optical sensors 321a and 321b. The output information can reflect the energy of the photons excited by the photon-gamma interaction 5 and detected by the optical sensors 321a and / or 321b. In some embodiments, the depth of the photon-gamma interaction 5 in the crystal element 311c (where the photon-gamma interaction 5 occurs) (also referred to as the target crystal element) can be determined based on the output information. For further description of determining the location information of photon-gamma interactions within the detector micro-block, please refer to other parts of this specification (e.g., Figure 8 (and related explanations).

[0110] 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. Various changes and modifications can be made by those skilled in the art based on the teachings of this specification. However, these changes and modifications do not depart from the scope of this specification. In some embodiments, the detector microblock 300 may include any suitable number or count of detector units. For example, the detector microblock 300 may include, for example, three, four, five, six, or other numbers of detector units.

[0111] Figures 6A-6F This is a top view schematic diagram of an exemplary detector block according to some embodiments of this specification.

[0112] In some embodiments, a detector block may include a plurality of detector microblocks (e.g., detector microblocks 300) arranged in a certain arrangement (or configuration). For example, the plurality of detector microblocks 300 may be arranged in the form of a block array. By way of example only, the number (or count) of the plurality of detector microblocks 300 in the detector block can be determined based on the size of the detector block and the detector microblocks 300.

[0113] In some embodiments, multiple detector micro-blocks 300 in a detector block may have the same orientation. For ease of description, the orientation of the detector micro-block can be defined as the direction of the short side of the crystal element in the detector micro-block 300, which may be perpendicular to the surface formed by the extension direction and the long side direction of each crystal element in the detector micro-block 300. Figure 5A Taking the detector micro-block 300 as an example, the orientation of the detector micro-block 300 can be represented by an arrow parallel to the short side of the crystal element in the detector micro-block 300.

[0114] In some embodiments, the short sides of the crystal elements in the plurality of detector microblocks 300 may be parallel to each other. That is, the orientation of each detector microblock 300 in the plurality of detector microblocks in the detector block may be the same. For example, as Figure 6A As shown, detector block 600A may include eight detector microblocks 300 facing the same direction, forming a four-row, two-column block array. The long side of each crystal element in each detector microblock 300 can be parallel to the row direction of the block array, and the short side can be parallel to the column direction of the block array. That is, the orientation of each detector microblock 300 is parallel to the column direction. For example, as... Figure 6B As shown, the detector block 600B may include eight detector microblocks 300, forming a four-row, two-column block array. The long side of each crystal element in each detector microblock 300 is parallel to the column direction of the block array, and the short side is parallel to the row direction of the block array. That is, the orientation of each detector microblock 300 is parallel to the row direction.

[0115] In some embodiments, the short side of the crystal element in one or more first detector units among the plurality of detector microblocks 300 may be perpendicular to the short side of the crystal element in one or more second detector units among the plurality of detector microblocks 300. That is, the plurality of detector microblocks 300 in the detector block may have different orientations.

[0116] For example, such as Figure 6C As shown, the detector block 600C may include eight detector microblocks 300, forming a four-row, two-column block array. Four first detector microblocks 300a can form the left column, and four second detector microblocks 300b can form the right column. In the left column, the orientation of each first detector microblock 300a can be parallel to the column direction. In the right column, the orientation of each second detector microblock 300b can be parallel to the row direction. That is, the orientation of the first detector microblocks 300a in the left column can be perpendicular to the orientation of the second detector microblocks 300b in the right column.

[0117] For example, such as Figure 6DAs shown, the detector block 600D may include 64 detector microblocks 300, arranged in an eight-row, eight-column array. The short sides of the crystal elements of each pair of adjacent detector microblocks 300 can be perpendicular to each other to form a checkerboard structure. That is, each pair of adjacent detector microblocks may include a first detector microblock and a second detector microblock to form a checkerboard structure. Each pair of adjacent detector microblocks may refer to two detector microblocks that are adjacent to each other in the same column or row. This is only an example. Figure 6D As shown, the orientations of adjacent detector microblocks 300c and 300d can be perpendicular to each other, and the orientations of adjacent detector microblocks 300e and 300f can also be perpendicular to each other. Therefore, detector block 600D can have a checkerboard structure.

[0118] For example, such as Figure 6E As shown, detector block 600E may include 16 detector microblocks 300, forming a four-row, four-column block array. The two columns of detector microblocks on the left can have the same arrangement as detector block 600C, and the two columns of detector microblocks on the right can have the same arrangement as detector block 600D.

[0119] In some embodiments, the plurality of detector micro-blocks 300 in the detector block may include a first sub-block and a second sub-block. Each first sub-block and second sub-block may include a plurality of detector micro-blocks, the detector micro-blocks of each first sub-block may have a first arrangement, and the detector micro-blocks of each second sub-block may have a second arrangement different from the first arrangement. This is merely an example. Figure 6F As shown, detector block 600F includes first sub-blocks 610 and 640 and second sub-blocks 620 and 630. The first sub-blocks 610 and 640 may have the same arrangement as detector block 600C, while the second sub-blocks 620 and 630 may have the same arrangement as detector block 600D.

[0120] In some embodiments, the plurality of detector micro-blocks 300 in a detector block can be randomly arranged. For example, the orientation of each detector micro-block 300 in the detector block can be randomly determined. For instance, when the parameter value corresponding to the orientation is 0, the orientation of the detector micro-block 300 is parallel to the column direction. When the parameter value corresponding to the orientation is 1, the orientation of the detector micro-block 300 is parallel to the row direction. The parameter value corresponding to the orientation of each detector micro-block 300 can be randomly determined according to the system default setting or manually set by the user. Then, the plurality of detector micro-blocks 300 can be arranged according to the parameter value corresponding to the orientation of each detector micro-block 300 to form a detector block. It should be noted that the parameter values ​​0 and 1 are provided for illustrative purposes and are not intended to limit the scope of this specification.

[0121] In some embodiments, since the detector micro-block 300 has a U-shaped structure, the slotting / opening direction of the U-shaped structure of the detector micro-block 300 can be defined as the orientation of the detector micro-block. The slotting direction refers to the through-path direction of the slot in the U-shaped structure. For example, the slotting direction could be... Figure 5A The second direction in.

[0122] See also Figures 6A-6D ,like Figure 6A As shown, the orientation of each detector micro-block 300 in detector block 600A is parallel to the column direction. Figure 6B As shown, the orientation of each detector micro-block 300 in detector block 600B is parallel to the row direction. Figure 6C As shown, in detector block 600C, the orientation of each detector micro-block 300a in the left column is parallel to the column direction, and the orientation of each detector micro-block 300b in the right column is parallel to the row direction. That is, the orientation of the detector micro-block 300a in the left column is perpendicular to the orientation of the detector micro-block 300b in the right column. Figure 6D As shown, detector block 600D comprises 64 detector microblocks 300, arranged in an eight-row, eight-column array. Each row of detector microblocks 300 in detector block 600D, parallel to the diagonal direction of the block array, can have the same orientation, while the orientations of adjacent rows of detector microblocks parallel to the diagonal direction can be perpendicular to each other. For example, the first row of detector microblocks from detector microblocks 300c to 300e is parallel to the diagonal direction of the block array, and the orientation of each detector microblock 300 in the first row is parallel to the row direction of the block array. The second row of detector microblocks from detector microblocks 300d to 300f is parallel to the diagonal direction of the block array, and the orientation of each detector microblock 300 in the second row is parallel to the column direction of the block array. That is, the orientation of each detector microblock 300 in the first row can be perpendicular to the orientation of each detector microblock 300 in the second row.

[0123] Multiple detector blocks can be designed by arranging multiple detector micro-blocks in different configurations, thereby improving the applicability of the detector micro-blocks. In some embodiments, a detector block may include one or more first detector micro-blocks and one or more second detector micro-blocks, and the orientation of the one or more first detector micro-blocks is different from that of the one or more second detector micro-blocks. Therefore, the detector block can be used to acquire output information at different resolutions, thereby increasing the richness of the output information and improving the accuracy of the positional information of photon-gamma interactions and the ECT images generated based on the output information.

[0124] Figure 7This is a block diagram of an exemplary processing device 140 according to some embodiments of this specification. In some embodiments, the processing device 140 may be coupled to a computer-readable storage medium (e.g., Figure 1 The processing device 140 communicates with the storage device 150 shown and executes instructions stored in a computer-readable storage medium. The processing device 140 may include an acquisition module 710 and a determination module 720.

[0125] The acquisition module 710 can be used to acquire output information from the optical sensor of the detector microarray. Further description of acquiring the output information can be found elsewhere in this specification (e.g., step 802 and its related description).

[0126] The determination module 720 can be used to determine the location information of a photon-gamma interaction occurring within the crystal element of the detector microarray, based on the output information of the optical sensor. The location information can indicate the position of the photon-gamma interaction occurring within the crystal element of the detector microarray. Further description of determining the location information of the photon-gamma interaction can be found elsewhere in this specification (e.g., step 804 and its related description).

[0127] It should be noted that the above description of the processing device 140 is for illustrative purposes only and is not intended to limit the scope of this specification. Various changes and modifications can be made by those skilled in the art based on the description herein. However, these changes and modifications do not depart from the scope of this specification. For example, the processing device 140 may include a storage module for storing data generated by the modules described above in the processing device 140. As another example, one or more modules may be integrated into a single module to perform its function.

[0128] Figure 8 This is a flowchart of an exemplary procedure 800 for determining the location of photon-gamma interactions in a detector microarray, according to some embodiments of this specification. Procedure 800 can be... Figure 1 This is implemented in the imaging system 100 shown. For example, process 800 may be stored in storage device 150 as instructions (such as an application program) and invoked and / or executed by processing device 140.

[0129] In step 802, the processing device 140 (e.g., acquisition module 710) can acquire the output information of the optical sensor of the detector microarray.

[0130] The detector microarray can be used to detect annihilation photons generated by annihilation events during an ECT scan of an object. In some embodiments, the detector microarray may include one or more detector units arranged side-by-side along a second direction. Each of the one or more detector units may include a plurality of crystal elements and an array of optical sensors. The crystal elements may be arranged in a column along a first direction perpendicular to the second direction and in a row along the second direction. The array of optical sensors may include optical sensors arranged along the first direction. Further description of the detector microarray can be found in other parts of this specification, such as... Figures 5A-5D And related explanations.

[0131] When photon-gamma interaction occurs in a detector microarray coupled to an optical sensor, it can excite one or more optical photons, which can then be detected by at least one optical sensor in the detector microarray. In response to the detection of an optical photon, at least one optical sensor can output an electrical signal. This electrical signal is also referred to as output information in this specification. The output information may include the energy value detected by each of the at least one optical sensor. Alternatively, the output information may also be parameters other than the energy value, such as signal strength or pulse width.

[0132] Taking detector microblock 300 as an example, when photon-gamma interaction occurs in detector microblock 300 coupled to optical sensors 321a, 321b, 341a, and 341b, one or more optical photons can be excited through photon-gamma interaction and detected by at least one of the optical sensors 321a, 321b, 341a, and 341b. Correspondingly, at least one of the optical sensors 321a, 321b, 341a, and 341b can output output information.

[0133] In some embodiments, the processing device 140 may obtain output information from an imaging device (e.g., imaging device 110) or a storage device (e.g., storage device 150, database, or external storage device) that stores the output information.

[0134] In step 804, the processing device 140 (e.g., the determination module 720) can determine the location information of the photon-gamma interaction occurring in the crystal element of the detector microarray based on the output information of the optical sensor.

[0135] Position information can indicate the location of photon-gamma interactions occurring within the crystal elements of the detector microarray. For example, position information may include a target crystal element array, a target crystal element, first position information of photon-gamma interactions along a first direction, second position information of photon-gamma interactions along a second direction, and third position information of photon-gamma interactions along a third direction perpendicular to the first and second directions. A target crystal element array refers to the array of crystal elements where photon-gamma interactions occur, and a target crystal element refers to the crystal element where photon-gamma interactions occur.

[0136] In some embodiments, the processing device 140 can determine the target crystal element column based on the output information of the optical sensors. Taking the detector micro-block 300 as an example again, when optical sensors 321a and 321b detect energy, but optical sensors 341a and 341b do not detect energy, or when the energy detected by optical sensors 341a and 341b is less than an energy threshold, the processing device 140 can determine crystal element column 350a as the target crystal element column. The energy threshold reflects the minimum energy at which the optical sensors can detect photon-gamma interactions. In some embodiments, the energy threshold can be determined according to system default settings or manually set by the user. For example, when optical sensors 321a, 321b, 341a, and 341b detect energy, the processing device 140 can determine crystal element column 350b or a crystal element column including crystal elements 331a and 331c as the target crystal element column.

[0137] In some embodiments, the processing device 140 can determine the target crystal element based on the output information of the optical sensor and the target crystal element column. For example, after determining that crystal element column 350a is the target crystal element, the target crystal element can be determined by comparing the output information corresponding to optical sensors 321a and 321b. For example, if the energy value in the output information corresponding to optical sensor 321a is greater than the energy value in the output information corresponding to optical sensor 321b, crystal element 311a can be determined as the target crystal element.

[0138] In some embodiments, the processing device 140 can determine the first position information and the second position information based on the output information of the optical sensor. For example, the centroid method can be used to determine the first position information and the second position information in the detector micro-block 300 where photon-gamma interaction occurs. The centroid method can be expressed by formula (1):

[0139]

[0140] Where X refers to the abscissa of the position where photon-gamma-ray interaction occurs in the detector micro-block 300 (i.e., the second position information); Y refers to the ordinate of the position where photon-gamma-ray interaction occurs in the detector micro-block 300 (i.e., the first position information); A refers to the energy detected by the optical sensor 341b corresponding to crystal elements 331c and 331d; B refers to the energy detected by the optical sensor 321b corresponding to crystal elements 311c and 311d; C refers to the energy detected by the optical sensor 341a corresponding to crystal elements 331a and 331b; and D refers to the energy detected by the optical sensor 321a corresponding to crystal elements 311a and 311b. In some embodiments, a coordinate system corresponding to (X, Y) is established with the intersection of crystal elements 331a, 331c, 311b, and 311d as the origin, the second direction as the abscissa axis, and the first direction as the ordinate axis.

[0141] In some embodiments, the processing device 140 may determine a target crystal element column and / or a target crystal element based on first location information and second location information. For example, the processing device 140 may determine a target crystal element column and / or a target crystal element based on the x-coordinate and y-coordinate of the position of the photon-gamma interaction occurring in the detector microblock 300.

[0142] In some embodiments, the third position information of the photonic gamma interaction can be determined based on the output information of the optical sensor, the first position information, and the second position information. The third position information refers to the depth (i.e., DOI) of the photonic gamma interaction in the target crystal element along a third direction. For example, the DOI may include the distance between the photonic gamma interaction and the first end S1 of the target crystal element along the extension direction of the target crystal element (i.e., the third direction).

[0143] In some embodiments, after determining the first location information and the second location information, the processing device 140 can determine the target crystal element, the target crystal element array, the target optical sensor among the optical sensors corresponding to the target crystal element, and the auxiliary optical sensor other than the target optical sensor among the optical sensors corresponding to the target crystal element array. Then, the processing device 140 can determine the DOI based on the first output information detected by the target optical sensor and the second output information detected by the auxiliary optical sensor. For example, the DOI can be determined based on the ratio of the energy detected by the target optical sensor to the energy detected by the auxiliary optical sensor. For example, the DOI d of the photon-gamma interaction within the target crystal element can be determined according to formula (2):

[0144] d = LUT[E1 / (E1+E2)], (2)

[0145] Where E1 represents the energy detected by the target optical sensor; E2 represents the energy detected by the auxiliary optical sensor; and LUT stands for lookup table operation. The lookup table can refer to a table recording the relationship between the depth of photon-gamma interaction in the target crystal element and the value of E1 / (E1+E2). In some embodiments, the lookup table can be determined based on multiple depths of photon-gamma interaction and their corresponding E1 / (E1+E2) values. The lookup table can be stored in the storage device of the imaging system 100 (e.g., storage device 150). When determining the DOI, the processing device 140 can retrieve the lookup table from the storage device and determine the DOI d of the photon-gamma interaction by searching the lookup table.

[0146] In some embodiments, the processing device 140 can generate ECT images based on DOIs of photon-gamma interactions. For example, the processing device 140 can generate response lines (LORs) based on DOIs of photon-gamma interactions and generate ECT images by processing the LORs. By generating LORs based on DOIs of photon-gamma interactions, the accuracy of LORs can be improved, thereby improving spatial and temporal resolution, and consequently improving the accuracy of PET images.

[0147] According to some embodiments of this specification, by introducing a special design structure of a U-shaped detector microblock, the positional information of photon-gamma interactions occurring in the crystal element of the detector microblock can be determined based on the output information of the optical sensor, thereby improving the resolution (e.g., spatial resolution) of the output information and thus improving the accuracy of the ECT image generated based on the output information. Furthermore, by using a U-shaped detector microblock, the amount of data that needs to be processed (e.g., output information) can be reduced, thereby improving data processing efficiency.

[0148] Figure 9 This is a flowchart of an exemplary ECT process 900 according to some embodiments of this specification. Process 900 can be... Figure 1 This is implemented in the imaging system 100 shown. For example, process 900 may be stored in storage device 150 as instructions (such as an application program) and invoked and / or executed by processing device 140.

[0149] In step 902, the processing device 140 (e.g., acquisition module 710) can acquire the output information of the optical sensors of multiple detector micro-blocks of one or more detector blocks in the detector.

[0150] In some embodiments, when an imaging device (e.g., imaging device 110) is used to perform an ECT scan on an object, optical sensors of multiple detector micro-blocks in one or more detector blocks of the imaging device can acquire output information. For each optical sensor, the method of acquiring the output information can be similar to the method of acquiring the output information in step 802, and will not be repeated here.

[0151] In step 904, the processing device 140 (e.g., partitioning module 730) can partition the output information into a first subset and a second subset.

[0152] The first subset may correspond to the optical sensors of one or more first detector microblocks, and the second subset may correspond to the optical sensors of one or more second detector microblocks. In some embodiments, the plurality of detector microblocks may include one or more first detector microblocks and one or more second detector microblocks. The short side of the crystal element in one or more first detector microblocks may be perpendicular to the short side of the crystal element in one or more second detector microblocks. For example, the short side of the crystal element in one or more first detector microblocks of the plurality of detector microblocks may be parallel to the row direction of the block array, and the short side of the crystal element in one or more second detector microblocks of the plurality of detector microblocks may be parallel to the column direction of the block array. Further description of one or more first detector microblocks and one or more second detector microblocks can be found in other parts of this specification, such as Figures 6C-6F And related explanations.

[0153] For example, the processing device 140 can divide the output information into a first subset and a second subset based on whether the corresponding optical sensor belongs to a first detector unit or a second detector unit.

[0154] In step 906, the processing device 140 (e.g., generation module 740) can generate a first ECT image based on a first subset and a second ECT image based on a second subset.

[0155] In some embodiments, the processing device 140 can generate a first ECT image by reconstructing a first subset using a first imaging reconstruction algorithm. Exemplary imaging reconstruction algorithms may include analytical methods (e.g., filtered backprojection algorithms), iterative methods, maximum likelihood expectation maximization (MLEM) algorithms, ordered subset expectation maximization (OSEM) algorithms, and any combination thereof. Similarly, a second ECT image can be generated by reconstructing a second subset using a second imaging reconstruction algorithm. The second imaging reconstruction algorithm may be the same as or different from the first imaging reconstruction algorithm.

[0156] Because the short side of the crystal element of one or more first detector micro-blocks is perpendicular to the short side of the crystal element of one or more second detector micro-blocks, the half-maximum full width (FWHM) of the crystal element of the first detector micro-block can be different from that of the crystal element of the second detector micro-block. Therefore, the resolution of the first subset can be different from the resolution of the second subset. Resolution refers to temporal resolution, spatial resolution, depth-of-field resolution, etc., or any combination thereof. For example, see... Figure 6D Since the field-wise wave size (FWHM) of the crystal element in detector micro-block 300c along the first direction is greater than that of the crystal element in detector micro-block 300d along the first direction, the resolution (e.g., spatial resolution) of the first subset along the first direction can be greater than the resolution of the second subset along the first direction. Correspondingly, the first image resolution of the first ECT image along the first direction can be greater than the second image resolution of the second ECT image along the first direction. Similarly, the first image resolution of the first ECT image along the second direction can be less than the second image resolution of the second ECT image along the second direction.

[0157] In some embodiments, the processing device 140 may generate a third ECT image based on a first subset and a second subset. For example, the third ECT image may be generated by reconstructing the first subset and the second subset using a third imaging reconstruction algorithm. The third imaging reconstruction algorithm may be the same as or different from the first imaging reconstruction algorithm and / or the second imaging reconstruction algorithm.

[0158] Since the third ECT image is generated based on the first and second subsets, the resolution of the third ECT image along the first direction can be greater than the resolution of the second ECT image along the first direction, and less than the resolution of the first ECT image along the first direction. Similarly, the resolution of the third ECT image along the second direction can be less than the resolution of the second ECT image along the second direction, and greater than the resolution of the first ECT image along the second direction.

[0159] According to some embodiments in this specification, first ECT images, second ECT images, and third ECT images with different image resolutions can be generated based on a first subset and a second subset. Therefore, the systems and methods provided in this specification can meet different imaging requirements and have a wider range of applications.

[0160] For example, arranging detector micro-pieces in a checkerboard pattern can improve the detector's imaging performance (e.g., resolution). This is just one example. Figure 10As shown, the image in box 1002 has a higher image resolution than the image in box 1004. The image in box 1002 was obtained using a detector with a checkerboard structure, while the image in box 1004 was obtained using a conventional detector.

[0161] It should be noted that the descriptions of processes 800 and 900 are provided for illustrative purposes and are not intended to limit the scope of this specification. Various changes and modifications can be made by those skilled in the art based on the teachings of this specification. For example, processes 800 and 900 may be performed by one or more additional operations not described and / or by one or more operations not discussed. Furthermore, the order of operations in processes 800 and 900 is not intended to be limiting. However, these changes and modifications must not depart from the scope of protection of this specification.

[0162] The basic concepts have been described above. Obviously, for those skilled in the art, the detailed disclosure above is merely illustrative and does not constitute a limitation of this specification. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this specification. Such modifications, improvements, and corrections are suggested in this specification and therefore remain within the spirit and scope of the exemplary embodiments described herein.

[0163] Furthermore, this specification uses specific terms to describe embodiments thereof. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "an embodiment," "one embodiment," or "an alternative embodiment" in different locations throughout this specification do not necessarily refer to the same embodiment. Moreover, certain features, structures, or characteristics in one or more embodiments of this specification can be appropriately combined.

[0164] 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 specification are not intended to limit the order of the processes and methods described herein. Although various examples have been discussed in the foregoing disclosure of some embodiments of the invention that are currently considered useful, 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 spirit and scope of the embodiments described herein. For example, while the system components described above can be implemented using hardware devices, they can also be implemented solely using software solutions, such as installing the described system on existing servers or mobile devices.

[0165] Similarly, it should be noted that, in order to simplify the description disclosed herein and thus aid in the understanding of one or more embodiments of the invention, the foregoing description of embodiments in this specification may sometimes combine multiple features into a single embodiment, drawing, or description thereof. However, this method of disclosure does not imply that the subject matter of this specification requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of a single embodiment disclosed above.

[0166] In some embodiments, numbers describing the quantity of components and attributes 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%. Correspondingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed according to 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 fields and parameters used to confirm their breadth of range in some embodiments of this specification are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

[0167] For each patent, patent application, patent application publication, and other material, such as articles, books, specifications, publications, and documents, referenced in this specification, the entire contents of which are incorporated herein by reference. This excludes historical application documents that are inconsistent with or conflict with the content of this specification, as well as documents that limit the broadest scope of the claims in this specification (currently or subsequently appended to this specification). It should be noted that in the event of any inconsistency or conflict between the descriptions, definitions, and / or terminology used in the supplementary materials to this specification and the content of this specification, the descriptions, definitions, and / or terminology used in this specification shall prevail.

[0168] Finally, it should be understood that the embodiments described in this specification are merely illustrative of the principles of the embodiments described herein. Other variations may also fall within the scope of this specification. Therefore, alternative configurations of the embodiments described herein are intended to be illustrative rather than limiting, and should be considered consistent with the teachings of this specification. Correspondingly, the embodiments of this specification are not limited to those explicitly described and illustrated herein.

Claims

1. A detector block for transmitting computed tomography scans, comprising: Multiple detector microblocks are arranged in a block array, wherein each detector microblock comprises: Detector units arranged side-by-side along a second direction, wherein each detector unit comprises: Crystal elements, the crystal elements being arranged in rows along a second direction and in columns along a first direction perpendicular to the second direction, each crystal element including a first end and a second end, extending from the first end to the second end along a third direction perpendicular to both the first and second directions, wherein each crystal element includes a long side along the first direction and a short side along the second direction, the length of the long side along the first direction being greater than the length of the short side along the second direction; and An optical sensor array, the optical sensor array comprising optical sensors arranged along the first direction; wherein, In each row of crystal elements, a first end of the crystal element is optically coupled to an optical sensor in the optical sensor array, and An optical bridge is provided at the second end of each crystal element in each column of crystal elements. The short side of the crystal element of one or more first detector microblocks of the plurality of detector microblocks is perpendicular to the short side of the crystal element of one or more second detector microblocks of the plurality of detector microblocks.

2. The detector block according to claim 1, characterized in that, For each of the crystal element columns in each of the detector units An optical separator is provided between each pair of adjacent crystal elements in the crystal element column; The optical splitter extends from the first end of a corresponding pair of adjacent crystal elements, but does not reach the second end of the corresponding pair of adjacent crystal elements.

3. The detector block according to claim 1, characterized in that, For each of the detector units An optical separator is provided between each pair of adjacent crystal element columns in the detector unit; The optical splitter extends from the first end of the crystal element in a corresponding pair of adjacent crystal element columns to the second end of the crystal element in the corresponding pair of adjacent crystal element columns.

4. The detector block according to claim 1, characterized in that, For each column of crystal elements in each of the detector units An optical separator is disposed between each pair of adjacent crystal elements in the crystal element array, the optical separator extending from a first end of the corresponding pair of adjacent crystal elements to a second end of the corresponding pair of adjacent crystal elements, and The optical bridge includes an optical propagation medium that covers the second end of the crystal element in the crystal element column.

5. The detector block according to claim 1, characterized in that, An optical separator is provided between each pair of adjacent detector units in the detector microblock; The optical splitter extends from the second end of the crystal element in the corresponding pair of adjacent detector units, but does not reach the first end of the crystal element in the corresponding pair of adjacent detector units.

6. The detector block according to claim 1, characterized in that, For each of the detector units In each column of crystal elements in the detector unit, two crystal elements are arranged along the first direction, and In each row of crystal elements in the detector unit, two crystal elements are arranged along the second direction.

7. The detector block according to claim 1, characterized in that, Each pair of adjacent detector microblocks in the plurality of detector microblocks includes one first detector microblock and one second detector microblock to form a checkerboard structure, wherein, Each row of detector microblocks in the detector block, parallel to the diagonal direction of the block array, has the same orientation, and / or The orientations of adjacent rows of detector micro-blocks parallel to the diagonal direction are perpendicular to each other.

8. The detector block according to claim 1, characterized in that, The detector block comprises multiple detector micro-blocks arranged in a checkerboard pattern in the block array manner.

9. The detector block according to claim 8, characterized in that, Each pair of adjacent detector microblocks in the checkerboard structure includes a first detector microblock and a second detector microblock, wherein the short side of the crystal element of the first detector microblock is perpendicular to the short side of the crystal element of the second detector microblock.

10. A method for transmitting a computed tomography (ECT) scan, performed on a computer including one or more processors and one or more storage devices, the method comprising: Obtain the output information of the optical sensors in the plurality of detector microblocks of the detector block as described in claim 1; The output information is divided into a first subset and a second subset, wherein the first subset corresponds to the optical sensor of the one or more first detector micro-blocks, and the second subset corresponds to the optical sensor of the one or more second detector micro-blocks. Generate a first ECT image based on the first subset; as well as A second ECT image is generated based on the second subset.

11. The method according to claim 10, characterized in that, The first image resolution of the first ECT image along the first direction is greater than the second image resolution of the second ECT image along the first direction, and the first image resolution of the first ECT image along the second direction is less than the second image resolution of the second ECT image along the second direction.

12. The method according to claim 11, characterized in that, The method further includes: A third ECT image is generated based on the first subset and the second subset.

Images