Detection module and decoding method thereof, detector and emission imaging equipment

Abstract

The invention provides a detection module and a decoding method thereof, a detector and emission imaging equipment. The detection module comprises a plurality of scintillation crystals which are provided with first end faces, second end faces opposite to the first end faces and side faces connected between the first end faces and the second end faces. The first reflecting layer covers the side surfaces of the plurality of scintillation crystals, and the first reflecting layer between any adjacent scintillation crystals on the preset arrangement path comprises a light-transmitting window, so that a light path passing through all scintillation crystals and the light-transmitting window on the preset arrangement path is formed; a plurality of photosensors coupled to a first end face of at least a portion of the plurality of scintillation crystals and less than the plurality of scintillation crystals in number, visible light photons within each of the plurality of scintillation crystals being conductible to at least two of the plurality of photosensors via an optical path; and a second reflective layer covering second end surfaces of the plurality of scintillation crystals. Therefore, fewer photoelectric sensors can be adopted, detection of more scintillation crystals is realized, and the cost is reduced.

Description

Technical Field

[0001] This invention relates to the technical field of emission imaging equipment, specifically to a detection module and a decoding method for its reaction position and / or reaction depth, a detector, and an emission imaging device. Background Technology

[0002] With the continuous advancement of science and technology, people have increasingly more means to treat complex diseases. Computed tomography (CT) technology represents a major breakthrough in the field of nuclear medicine imaging equipment. Emission computed tomography (ECT), also known as radionuclide computed tomography, is an imaging technique that can display the distribution and three-dimensional image of radionuclides at various levels within the human body. ECT can detect organ metabolism and blood flow status, and is a dynamic, functional imaging technique. Currently, positron emission tomography (PET) and single-photon emission computed tomography (SPECT) are the most commonly used ECT techniques.

[0003] The core component of ECT (Electro-Conductive Photodetector) is the detection module. The detection module consists of a scintillation crystal and a photodetector coupled together. High-energy photons (γ photons) of 511 keV generated by the annihilation effect react within the scintillation crystal and are converted into visible photon groups. Currently, commercially available photodetectors typically use ordinary photomultiplier tubes (PMs) or silicon photomultiplier tubes (SiPMs). As an advanced photon detector, SiPMs possess excellent photon detection efficiency, superior temporal resolution, and sensitivity to weak signals, making them dominant in high-precision imaging applications. Furthermore, unlike ordinary photomultiplier tubes, SiPMs are smaller and do not require high voltage during operation.

[0004] However, SiPMs are relatively expensive to manufacture, especially when large-scale SiPM arrays are required, which often significantly increases the cost of the detector system. Therefore, reducing the number of SiPMs used while maintaining image quality has become an important direction for optimizing system design. Summary of the Invention

[0005] To at least partially address the problems existing in the prior art, according to one aspect of the present invention, a detection module is provided, comprising: a plurality of scintillation crystals, each of the plurality of scintillation crystals having a first end face, a second end face opposite to the first end face, and a side face connected between the first end face and the second end face, the plurality of scintillation crystals being arranged in an array adjacent to each other along a predetermined arrangement path; a first reflective layer covering the side face of the plurality of scintillation crystals, the first reflective layer between any adjacent scintillation crystals on the predetermined arrangement path including a light-transmitting window to form an optical path through all scintillation crystals and the light-transmitting window on the predetermined arrangement path; a plurality of photoelectric sensors, fewer in number than the plurality of scintillation crystals, the plurality of photoelectric sensors being coupled to at least a portion of the first end face of the plurality of scintillation crystals such that visible light photons in each of the plurality of scintillation crystals can be conducted to at least two of the plurality of photoelectric sensors via the optical path; and a second reflective layer covering the second end face of the plurality of scintillation crystals.

[0006] For example, multiple photoelectric sensors are arranged in a manner corresponding to a portion of a predetermined arrangement path, such that the projections of the multiple photoelectric sensors onto the first end face of the multiple scintillation crystals only cover a portion of the first end face of the multiple scintillation crystals.

[0007] For example, the plurality of photoelectric sensors are configured corresponding to a portion of the plurality of scintillation crystals, and the first end face of each scintillation crystal in the portion of the plurality of scintillation crystals is coupled to the corresponding photoelectric sensor.

[0008] For example, each of the plurality of scintillation crystals is coupled to the photoelectric sensor such that at least a portion of adjacent scintillation crystals are co-coupled to the same photoelectric sensor.

[0009] For example, the plurality of scintillation crystals include a first scintillation crystal, a second scintillation crystal, and a third scintillation crystal and a fourth scintillation crystal located between the two along a predetermined arrangement path, wherein the third scintillation crystal and the first scintillation crystal are adjacent to each other, and the fourth scintillation crystal and the second scintillation crystal are adjacent to each other. The plurality of photoelectric sensors include a first photoelectric sensor and a second photoelectric sensor, wherein: a first end face of the first scintillation crystal is coupled to the first photoelectric sensor, a first end face of the second scintillation crystal is coupled to the second photoelectric sensor; and / or a first end face of the third scintillation crystal is coupled to the first photoelectric sensor, and a first end face of the fourth scintillation crystal is coupled to the second photoelectric sensor.

[0010] For example, when the first end face of the first scintillation crystal is coupled to the first photoelectric sensor and the first end face of the second scintillation crystal is coupled to the second photoelectric sensor: the light-transmitting window in the first reflective layer between the first scintillation crystal and the third scintillation crystal is adjacent to the second end face; the light-transmitting window in the first reflective layer between the second scintillation crystal and the fourth scintillation crystal is set to be adjacent to the second end face; and the light-transmitting window in the first reflective layer between the third scintillation crystal and the fourth scintillation crystal is adjacent to the first end face.

[0011] For example, in the case where the first end face of the third scintillation crystal is coupled to the first photodetector and the first end face of the fourth scintillation crystal is coupled to the second photodetector: the light-transmitting window in the first reflective layer between the first and third scintillation crystals includes a first sub-window adjacent to the first end face and a second sub-window adjacent to the second end face; the light-transmitting window in the first reflective layer between the second and fourth scintillation crystals includes a third sub-window adjacent to the first end face and a fourth sub-window adjacent to the second end face; and the light-transmitting window between the third and fourth scintillation crystals is adjacent to the first end face.

[0012] For example, when the first end face of the first scintillation crystal and the first end face of the third scintillation crystal are jointly coupled to the first photoelectric sensor, and the first end face of the second scintillation crystal and the first end face of the fourth scintillation crystal are jointly coupled to the second photoelectric sensor: the light-transmitting window in the first reflective layer between the first scintillation crystal and the third scintillation crystal is adjacent to the second end face, the light-transmitting window in the first reflective layer between the second scintillation crystal and the fourth scintillation crystal is adjacent to the second end face, and the light-transmitting window in the first reflective layer between the third scintillation crystal and the fourth scintillation crystal is adjacent to the first end face.

[0013] For example, a portion of the first end face of each of the first and third scintillation crystals is covered with a third reflective layer, and the uncovered portions of the first end faces of both the first and third scintillation crystals form a first coupling opening, through which the first and third scintillation crystals are coupled to a first photoelectric sensor; a portion of the first end face of each of the second and fourth scintillation crystals is covered with a third reflective layer, and the uncovered portions of the first end faces of both the second and fourth scintillation crystals form a second coupling opening, through which the second and fourth scintillation crystals are coupled to a second photoelectric sensor.

[0014] For example, the first end face of the first scintillation crystal and the first end face of the third scintillation crystal are coupled to the first photoelectric sensor through a tapered first light guide, and the first end face of the second scintillation crystal and the first end face of the fourth scintillation crystal are coupled to the second photoelectric sensor through a tapered second light guide.

[0015] For example, the plurality of scintillation crystals include a first scintillation crystal, a second scintillation crystal, and a fifth scintillation crystal located between the two along a predetermined arrangement path, and the plurality of photoelectric sensors include a first photoelectric sensor and a second photoelectric sensor, with a first end face of the first scintillation crystal coupled to the first photoelectric sensor, and a first end face of the second scintillation crystal coupled to the second photoelectric sensor.

[0016] For example, the light-transmitting windows in the first reflective layer between the first scintillation crystal and the fifth scintillation crystal are all adjacent to the second end face; and the light-transmitting windows in the first reflective layer between the second scintillation crystal and the fifth scintillation crystal are adjacent to the second end face.

[0017] For example, the predetermined layout path is in the form of a straight line, a C-shape, an O-shape, or an S-shape.

[0018] Another aspect of this application provides a detector comprising a plurality of detection modules, at least one of which is the aforementioned detection module.

[0019] For example, the plurality of detection modules include a primary detection module and a secondary detection module arranged adjacent to each other. The primary detection module is the detection module described above. The first reflective layer between the sides of adjacent scintillation crystals between the primary detection module and the secondary detection module includes a light-transmitting window. The light-transmitting window is configured to allow visible light photons in any scintillation crystal of the secondary detection module to be conducted to the optical path of the primary detection module and detected by at least two optical sensors in the primary detection module.

[0020] For example, the primary detection module includes a first primary detection module and a second primary detection module that are respectively adjacent to the secondary detection module. The light-transmitting window includes a light-transmitting window between the sides of adjacent scintillation crystals between the first primary detection module and the secondary detection module, and a light-transmitting window between the sides of adjacent scintillation crystals between the second primary detection module and the secondary detection module. At least two optical sensors include optical sensors in the first primary detection module and / or the second primary detection module.

[0021] For example, there are multiple secondary detection modules arranged between the first and second primary detection modules. The first reflective layer between the sides of adjacent scintillation crystals between any two secondary detection modules includes a light-transmitting window, which is configured to allow visible light photons in any scintillation crystal within any secondary detection module to be transmitted to the adjacent secondary detection module.

[0022] For example, a light-transmitting window is provided between adjacent scintillation crystals in the secondary detection module.

[0023] Another aspect of this application provides an emission imaging device, including the detector described above; and a processor module, the processor module being electrically connected to the photoelectric sensor of the detector, the processor module being used to: determine the number of transparent windows through which visible light photons reach the multiple photoelectric sensors based on the photon intensity received by the multiple photoelectric sensors in the same detection module and the photon transmittance of the transparent window, and then decode the position of the scintillation crystal of the detection module where the event occurs.

[0024] For example, the processor module is also configured to: determine the total length of the scintillation crystal through which visible light photons pass to reach multiple photoelectric sensors based on the photon intensity and the length of a single scintillation crystal, and then decode the reaction depth in which the event occurs within the scintillation crystal.

[0025] Another aspect of this application provides a method for decoding the above-mentioned detection module, comprising: decoding the position of the scintillation crystal where the event occurs based on the photon intensities of at least two of the multiple photoelectric sensors and the photon transmittance of the light-transmitting window; and determining the total length of visible light photons reaching at least two scintillation crystals respectively based on the photon intensities of at least two of the multiple photoelectric sensors and the length of a single scintillation crystal, thereby decoding the reaction depth in which the event occurs within the scintillation crystal.

[0026] For example, the plurality of photoelectric sensors include a first photoelectric sensor and a second photoelectric sensor, and the step of decoding the reaction depth where the event occurs within the scintillation crystal specifically includes:

[0027] Defining the calculation factor of reaction depth h :

[0028]

[0029] in S1 The intensity of photons received by the first photoelectric sensor. S2 The intensity of photons received by the second photoelectric sensor; and based on S 1+ S 2 and S 1 max + S 2 max The ratio or h The absolute value of is used to calculate the reaction depth in which the event occurs within the scintillation crystal, where S 1 max and S 2 max These are the maximum detection values ​​of the first and second photoelectric sensors, respectively, when the event occurs at the very middle of the optical path.

[0030] In summary, by rationally arranging the scintillation crystals and light-transmitting windows, a suitable optical path can be formed, allowing visible light photons generated within any scintillation crystal to reach at least two photodetectors. By using the ratio of photon intensities received by these two photodetectors, a smaller number of photodetectors can be used to perform response position decoding and response depth decoding on a larger number of scintillation crystals. Response position decoding determines which scintillation crystal the event occurred in, while response depth decoding determines the DOI (Domain of Interest) within that crystal. Response position decoding and response depth decoding improve the spatial resolution of the emission imaging device using this detection module, while fewer photodetectors significantly reduce the cost of the detection module, thereby reducing the cost of the emission imaging device using this module.

[0031] A series of simplified concepts are introduced in the description of the invention, which will be further explained in detail in the detailed description section. This description is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0032] The advantages and features of the present invention will be described in detail below with reference to the accompanying drawings. Attached Figure Description

[0033] The following figures are included as part of this invention for understanding its principles. The figures illustrate embodiments of the invention and their descriptions, serving to explain the principles of the invention. In the figures,

[0034] Figure 1 A schematic diagram of a detection module according to an exemplary embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of a detector according to an exemplary embodiment of the present invention, the detector comprising... Figure 1 The detection module shown;

[0036] Figure 3 This is a schematic diagram of a detector according to another exemplary embodiment of the present invention, the detector comprising... Figure 1 The detection module shown;

[0037] Figure 4 A comparison diagram of the calculated response lines and photon flight paths in flat-panel and ring-type emission imaging devices;

[0038] Figures 5 to 8 These are schematic diagrams of detection modules according to different embodiments of this application. Detailed Implementation

[0039] In the following description, numerous details are provided to enable a thorough understanding of the invention. However, those skilled in the art will appreciate that the following description merely illustrates preferred embodiments of the invention, and that the invention can be practiced without one or more of these details. Furthermore, to avoid obscuring the invention, some technical features well-known in the art have not been described in detail.

[0040] According to one aspect of the present invention, a detection module is provided. The detection module includes multiple scintillation crystals. A scintillation crystal is a crystal that can convert the energy of high-energy particles into light energy under the impact of gamma photons. The scintillation crystal can be a yttrium lutetium silicate scintillation crystal (LYSO crystal), a bismuth germanate scintillation crystal (BGO crystal), a cerium-doped lutetium silicate scintillation crystal (LSO crystal), a gadolinium silicate scintillation crystal (GSO crystal), a sodium iodide scintillation crystal (NaI crystal), or crystals of other materials. The detection module also includes multiple photoelectric sensors. The multiple photoelectric sensors can be of various types, either existing or potentially emerging in the future, such as photomultiplier tubes (PMTs), silicon photomultiplier tubes (SiPMs), etc. The scintillation crystals and photoelectric sensors will be described in detail below.

[0041] Figure 1 A detection module according to one embodiment of this application is shown. See also... Figure 1 The scintillation crystal 300 may have a first end face 310 and a second end face 320. The first end face 310 may be the end of the detection module 10 that is farther away from the organism to be detected during detection, and the second end face 320 may be the other end of the scintillation crystal 300 that is closer to the organism to be detected. Optionally, the second end face 320 may also be the end of the detection module 10 that is farther away from the organism to be detected during detection, and the first end face 310 may be the other end of the scintillation crystal 300 that is closer to the organism to be detected.

[0042] The scintillation crystal 300 may also have a side surface connecting the first end face 310 and the second end face 320. The scintillation crystal 300 is typically cuboid in shape, having four side surfaces between the first end face 310 and the second end face 320. Multiple scintillation crystals 300 are arranged in an array along a predetermined arrangement path, with their side surfaces adjacent to each other. Viewed from the first end face 310 or the second end face 320, the array of multiple scintillation crystals 300 can be arranged in any suitable shape, such as a circle, rectangle, or regular hexagon, as long as it allows multiple detection modules to be closely arranged into a detector as described below. Exemplarily, the predetermined arrangement path can be straight, U-shaped, O-shaped, or S-shaped. In embodiments where the predetermined arrangement path is straight, the scintillation crystals along the predetermined arrangement path can be arranged along rows or columns of a matrix, see [reference needed]. Figure 1In embodiments where the predetermined arrangement path is U-shaped or O-shaped, the scintillation crystals along the predetermined arrangement path can be arranged into a 2×n matrix. In embodiments where the predetermined arrangement path is S-shaped, the matrix of scintillation crystals along the predetermined arrangement path can have even more forms.

[0043] The detection module may include a first reflective layer 510, which covers the sides of a plurality of scintillation crystals 300. A first light-transmitting window, such as 611, 612, and 613, is provided in the first reflective layer 510 between any two adjacent scintillation crystals 300 along a predetermined arrangement path. The first light-transmitting window is located in... Figure 1 The white portion shown is sandwiched between the scintillation crystals 300. Any suitable optical coupling agent, such as optical adhesive, can be filled at the first light-transmitting window. Optionally, the first light-transmitting windows of adjacent scintillation crystals 300 can be filled with air. At least some of the scintillation crystals 300 may also have other sides spatially adjacent to other scintillation crystals 300, but not adjacent along a predetermined arrangement path. For distinction, these sides not adjacent along the predetermined arrangement path are referred to as other adjacent sides. The first reflective layer 510 between the other adjacent sides may not have a first light-transmitting window, but may be completely covered by the first reflective layer 510. Among the plurality of scintillation crystals 300 arranged along a predetermined arrangement path and having first light-transmitting windows between adjacent sides, visible light photons generated in any one scintillation crystal can reach other scintillation crystals 300 along the predetermined arrangement path. However, for two scintillation crystals 300 that are not spatially adjacent, since there are no adjacent sides, it is impossible to provide a first light-transmitting window that allows visible light photons to pass directly between the two scintillation crystals 300.

[0044] Figure 1 The black portion sandwiched between the scintillation crystals 300 shows the first reflective layer 510. Since the sides of the scintillation crystals 300 are not coupled to the photoelectric sensor, each side of the scintillation crystals 300 can be covered with a first reflective layer 510 that reflects light inwards towards the corresponding scintillation crystal 300. The first reflective layer 510 prevents visible light photons generated when a scintillation crystal 300 is struck by gamma photons from causing undesirable effects on adjacent scintillation crystals 300. Furthermore, the first reflective layer 510 prevents visible light photons from leaking out of the scintillation crystal 300, thereby enhancing the signal detected by the photoelectric sensor coupled to the scintillation crystal 300. Thus, when detecting visible light photons from a single scintillation crystal 300, the first reflective layer 510 can improve the accuracy of detection.

[0045] The detection module may also include a second reflective layer 520. Figure 1The black portion of the second end face 320 shows the second reflective layer 520. The second reflective layer 520 can cover the second end faces 320 of multiple scintillation crystals 300. Thus, visible light photons will not leak from the second end face 320 to the outside of the scintillation crystals 300, causing signal attenuation detected by the photoelectric sensor.

[0046] The first reflective layer 510 and the second reflective layer 520 can be formed by spraying, coating (e.g., spraying or silvering), or pasting reflective materials (e.g., ESR reflectors). As a high-efficiency reflector, ESR (Enhanced Specular Reflector) has a reflectivity of over 98% across the entire visible light spectrum, higher than other types of reflectors currently available. ESR itself is composed of a polymer film layer, making it a more environmentally friendly reflector material. The thickness of the ESR reflector is around 40 micrometers, for example, 38 micrometers.

[0047] The first reflective layer 510 between adjacent scintillation crystals 300 along a predetermined arrangement path may include first light-transmitting windows to form an optical path through all scintillation crystals 300 and all first light-transmitting windows along the predetermined arrangement path. As described above, first light-transmitting windows can only be provided on adjacent sides between two adjacent scintillation crystals 300 along the predetermined arrangement path to form an optical path. Typically, the transmittance of the first light-transmitting windows for visible light is 10% to 20%. In embodiments not shown, the transmittance of some first light-transmitting windows for visible light may be higher or lower than this range. The optical path here passes through all scintillation crystals 300 arranged along the predetermined arrangement path, and the first light-transmitting windows between any adjacent scintillation crystals 300 along the predetermined arrangement path. Thus, when visible light photons are generated in one of the scintillation crystals 300, these visible light photons can reach the adjacent scintillation crystal through the first light-transmitting window, and then reach the scintillation crystal spaced apart from the scintillation crystal that generated the visible light photons through another first light-transmitting window of that adjacent scintillation crystal. Thus, an optical path is formed through these scintillation crystals 300. It is easy to understand that the arrangement of the scintillation crystals 300 restricts the optical path to some extent. It is important to note that the optical path only represents the passage allowed for visible light photons, not the location where visible light photons are generated in the multiple scintillation crystals 300, or the direction of propagation of visible light photons.

[0048] The number m of photodetectors is less than the number n of scintillation crystals 300, i.e., m < n. The photodetectors are coupled to at least a portion of the first end face 310 of a plurality of scintillation crystals 300 arranged along a predetermined path. In one set of embodiments, m photodetectors may be coupled to m scintillation crystals 300. In another set of embodiments, m photodetectors may be coupled to n scintillation crystals 300, in which case one or more of the m photodetectors may be coupled to a plurality of scintillation crystals 300. Typically, the size of a scintillation crystal is substantially equivalent to the size of a photodetector. In this case, along the row or column direction of the array, a photodetector may be coupled to at most two scintillation crystals. In yet another set of embodiments, a portion of the m photodetectors are each coupled to a single scintillation crystal 300, while each of the other portions may be coupled to a plurality of scintillation crystals 300.

[0049] Visible light photons generated within each scintillation crystal 300 along a predetermined arrangement path can be transmitted to at least two photoelectric sensors via an optical path.

[0050] refer to Figure 1In the illustrated embodiment, four scintillation crystals 300 are arranged sequentially along a predetermined linear arrangement path. For ease of understanding, the four scintillation crystals 300 are labeled from left to right as first scintillation crystal C1, third scintillation crystal C3, fourth scintillation crystal C4, and second scintillation crystal C2, respectively. A first light-transmitting window, denoted as 611, 612, and 613, is provided between any two adjacent scintillation crystals 300 to form an optical path for transmitting visible light photons between the four scintillation crystals 300 via these first light-transmitting windows. Exemplarily, photoelectric sensors can be coupled to the scintillation crystals located at the ends of the optical path. These photoelectric sensors are labeled as first photoelectric sensor S1 and second photoelectric sensor S2, respectively. First photoelectric sensor S1 and second photoelectric sensor S2 are coupled to first scintillation crystal C1 and second scintillation crystal C2, respectively. The middle third scintillation crystal C3 and fourth scintillation crystal C4 are not coupled to the photoelectric sensors. Preferably, a reflective layer can be provided on the first end face 310 of the two middle scintillation crystals C3 and C4 to prevent visible light photon leakage. In this embodiment, if visible light photons are generated in the first scintillation crystal C1, most of these photons can reach the first photodetector S1, while the remainder passes through the first light-transmitting window 611 to the adjacent third scintillation crystal C3, and then travels through scintillation crystal C3 to the first light-transmitting window 612. Subsequently, the visible light photons can reach the fourth scintillation crystal C4, and through the fourth scintillation crystal C4 and the first light-transmitting window 613, finally reach the second scintillation crystal C2 and its coupled second photodetector S2. The transmission of visible light photons within these scintillation crystals is essentially due to continuous reflection by the reflective layer, and the reflectivity is not 100%. Therefore, during the reflection process, the visible light photons continuously attenuate, and the number of photons continuously decreases. Furthermore, visible light photons within each scintillation crystal can only partially pass through the first transmission window to reach adjacent scintillation crystals. Some of the visible light photons that do not reach adjacent scintillation crystals may become trapped within those crystals and attenuate through continuous reflection. Moreover, these photons may also be attenuated by the optical coupling medium at the first transmission window. Therefore, along the light path, visible light photons are attenuated by a portion each time they pass through a first transmission window. Finally, by determining the photon intensities received by the two photoelectric sensors, the position and / or depth information (DOI) of the scintillation crystal where the event occurred can be decoded.

[0051] In a predetermined arrangement path, any adjacent scintillation crystals form an optical path only through a first light-transmitting window. The location of the decoding response, i.e., the ratio of photon intensities received by the two photodetectors, can be used to determine which scintillation crystal the event occurred in. To simplify calculations, the transmission loss of visible light photons within the scintillation crystal can be ignored. For example, when the event occurs in the first scintillation crystal C1, most of the visible light photons reach the first photodetector S1, and the photon intensity received by the first photodetector S1 can be approximated as 1. The visible light photons can travel along the optical path through three first light-transmitting windows 611, 612, and 613 to reach the second photodetector S2. Based on the reasons analyzed above, the ratio (i.e., photon transmittance) of photons reaching the next scintillation crystal through each first light-transmitting window is k. Therefore, the ratio of photon intensities received by the second photodetector S2 to those received by the first photodetector S1 can be approximately equal to k. 3 / 1. If the event occurs in the third scintillation crystal C3, the first photodetector S1 coupled to the first scintillation crystal C1 can receive visible light photons attenuated through a first transmission window 601, and the second photodetector S2 coupled to the second scintillation crystal C2 can receive visible light photons attenuated through two first transmission windows 612 and 613. If the photon transmittance of each first transmission window is k, then the ratio of the photon intensities received by the second photodetector S2 to those received by the first photodetector S1 can be approximately equal to k. 2 The events occurring in the fourth scintillation crystal C4 and the second scintillation crystal C2 are similar to those occurring in the first scintillation crystal C1 and the third scintillation crystal C3, respectively. However, the photon intensities received by the two photodetectors in the fourth scintillation crystal C4 and the second scintillation crystal C2 are opposite to those received by the two photodetectors in the first scintillation crystal C1 and the third scintillation crystal C3. When the events occur in the fourth scintillation crystal C4 and the second scintillation crystal C2, the ratio of the photon intensities received by the second photodetector S2 to the first photodetector S1 can be approximately equal to 1 / k. 3 and k / k 2 Therefore, by comparing the ratio of photon intensities received by the two photoelectric sensors, the location of the scintillation crystal where the event occurred can be decoded, i.e., the location of the reaction.

[0052] After a gamma photon enters the scintillation crystal 300, it will travel a short distance (determined by the average attenuation length of the scintillation crystal 300) and then deposit all its energy. This short distance is called the DOI. Figure 4The diagram shows cross-sectional views of existing planar and ring-type positron emission tomography (PET) imaging devices. Solid lines represent the actual flight paths of gamma photons, while dashed lines represent the response lines generated by the imaging device based on the detected signals. This demonstrates that the depth effect significantly impacts the accuracy of photoelectric sensors in determining the location and path of gamma photons during the decoding process, resulting in a decrease in the spatial resolution of the PET imaging device.

[0053] Ignoring the loss of visible light photons caused by the light-transmitting window itself, the reaction depth information in the scintillation crystal can be determined by the ratio of photon intensities received by the two photoelectric sensors; that is, the decoding reaction depth. See also... Figure 1 Four scintillation crystals are arranged sequentially between two photodetectors. The closer the event occurs to one photodetector, the stronger the photon intensity detected; the weaker the photon intensity detected by the other photodetector. The attenuation of visible light photons within the scintillation crystals may be linear or nonlinear. However, generally speaking, the photon intensity received by the photodetectors is negatively correlated with the length of the photon's propagation within the scintillation crystal. For ease of understanding, neglecting the size of the first light-transmitting window, the distance a visible light photon travels within each scintillation crystal is approximately equal to the length L of the scintillation crystal. In other words, the photon intensity attenuated by a visible light photon after passing through one scintillation crystal is I1, and the photon intensity attenuated by a visible light photon after passing through two scintillation crystals is I2, roughly following the relationship: 2I1 = I2. When the event occurs at the very center of the first scintillation crystal C1, the visible light photon is attenuated by a scintillation crystal of length 0.5L to reach the first photodetector S1, and attenuated by a scintillation crystal of length 3.5L to reach the second photodetector S2. When the event occurs at the exact center of the third scintillation crystal C3, the visible light photons are attenuated by a scintillation crystal of length 1.5L before reaching the first photodetector S1, and then attenuated by a scintillation crystal of length 2.5L before reaching the second photodetector S2. And so on.

[0054] exist Figure 1 In the illustrated embodiment, the optical path between the two photoelectric sensors is approximately the length of four scintillation crystals, with three first light-transmitting windows 611, 612, and 613 in between. Due to limitations such as the sensitivity of existing sensors, further increasing the number of first light-transmitting windows and scintillation crystals may cause a significant attenuation of the intensity of visible light photons after passing through the scintillation crystals and the first light-transmitting windows, resulting in a further reduction in the signal-to-noise ratio. However, this application does not exclude embodiments in which more scintillation crystals are added between the third scintillation crystal C3 and the fourth scintillation crystal C4, and first light-transmitting windows are provided between these scintillation crystals and between them and the third scintillation crystal C3 and the fourth scintillation crystal C4.

[0055] In other embodiments, one or more photoelectric sensors may be coupled to other scintillation crystals, for example, a first photoelectric sensor S1 may be coupled to a third scintillation crystal C3 or / and a second photoelectric sensor S2 may be coupled to a fourth scintillation crystal C4.

[0056] In summary, by rationally arranging the scintillation crystals and the first light-transmitting window, a suitable optical path can be formed, allowing visible light photons generated within any scintillation crystal to reach at least two photoelectric sensors. By using the photon intensity ratio received by the at least two photoelectric sensors, a smaller number of photoelectric sensors can be used to perform response position decoding and response depth decoding on a larger number of scintillation crystals. Response position decoding determines which scintillation crystal the event occurred in, while response depth decoding determines the DOI (Domain of Interest) within that crystal. Response position decoding and response depth decoding improve the spatial resolution of the emission imaging device using this detection module, while fewer photoelectric sensors significantly reduce the cost of the detection module, thereby reducing the cost of the emission imaging device using this module.

[0057] exist Figure 1 In the illustrated embodiment, the detection module includes four scintillation crystals and two photoelectric sensors. However, in other embodiments not shown, more or fewer scintillation crystals and more photoelectric sensors may be included. The number of photoelectric sensors is less than the number of scintillation crystals to reduce cost. Exemplarily, the detection module may include three scintillation crystals and two photoelectric sensors, which will be described in more detail later. Exemplarily, the detection module may include four scintillation crystals and three photoelectric sensors, thereby enabling the detection module to detect more scintillation crystals and two photoelectric sensors. Figure 2 Based on this, a sensor can be added coupled to a third scintillation crystal C3 and / or a fourth scintillation crystal C4. When an event occurs in different scintillation crystals, the photon intensities received by the three photodetectors are different, thus enabling decoding. Exemplarily, the detection module may include five scintillation crystals and three photodetectors, with one photodetector coupled to the odd-numbered scintillation crystal along a predetermined arrangement path. Of course, in the case of a detection module including five scintillation crystals, it may also include only two photodetectors, with one photodetector coupled to the even-numbered scintillation crystal along a predetermined arrangement path. In summary, there are various ways to determine the number of scintillation crystals and photodetectors, as well as the coupling positions of the photodetectors. Based on the principles provided by this invention, those skilled in the art will understand these methods, and they will not be listed individually here.

[0058] According to another aspect of the present invention, a detector is provided. The detector may include a plurality of detection modules, at least one of which may be a detection module provided in the embodiments of this application.

[0059] For a detector with multiple detection modules, all of these detection modules can be the detection modules provided in the embodiments of this application. For example, in... Figure 2 In the illustrated embodiment, the detector may include a first detection module, a second detection module, a third detection module, and a fourth detection module arranged from top to bottom on the paper. All four detection modules employ... Figure 1 The illustrated detection module is completely separated from adjacent detection modules by a first reflective layer 510, preventing visible light photons from the scintillation crystal in each detection module from entering the scintillation crystal of the adjacent detection module. In the illustrated embodiment, each detection module includes four scintillation crystals 300 arranged in a left-right direction along the plane of the paper. The photoelectric sensors in the first detection module may include S11 and S12, and the photoelectric sensors in the second detection module may include S21 and S22. Similarly, the photoelectric sensors in the third detection module include S31 and S32, and the photoelectric sensors in the fourth detection module include S41 and S42. Compared to existing detection modules where each scintillation crystal is coupled with a photoelectric sensor, the solution provided by this embodiment can save 50% of the photoelectric sensors. Although Figure 2 The illustrated embodiment includes four detection modules, but in other embodiments not shown, each detector may include more or fewer detection modules. Additionally, although... Figure 2 The detection modules shown have the same structure, but in other embodiments not shown, one or more of these detection modules may have a different structure from the others. For example, the coupling position of the photoelectric sensor in one or more of these detection modules may not be used in other detection modules. Alternatively, the number and coupling position of the photoelectric sensors in one or more of these detection modules may not be used in other detection modules. Several other embodiments of detection modules will be provided later, in which one or more detection modules can be used with... Figure 1 The detection modules shown are used in combination.

[0060] In the detectors described above, each detection module includes a photoelectric sensor. In other detectors, some detection modules may not include photoelectric sensors, thus further reducing the number of photoelectric sensors required. Figure 3 A detector according to another embodiment of this application is shown. Figure 3 As shown, the detector may include a first detection module, a second detection module, a third detection module, and a fourth detection module arranged from top to bottom in the plane of the paper. Each detection module includes four scintillation crystals 300 arranged in a left-right direction in the plane of the paper. The first and fourth detection modules may employ the detection modules provided in this application. For example, they may employ similar... Figure 1The detection modules are as follows: Specifically, the first detection module may include photoelectric sensors S11 and S12 coupled to the scintillation crystals at both ends; the fourth detection module may include photoelectric sensors S41 and S42 coupled to the scintillation crystals at both ends. The first reflective layer between the sides of the scintillation crystals adjacent to the first and second detection modules may include one or more second light-transmitting windows 621, allowing a portion of the visible light photons generated in the second detection module to reach the optical path of the first detection module through the second light-transmitting window 621. Thus, they can be detected by the photoelectric sensors within the first detection module. The first reflective layer between the sides of the scintillation crystals adjacent to the third and fourth detection modules may include a second light-transmitting window 622, allowing a portion of the visible light photons generated in the third detection module to reach the fourth detection module. Thus, they can be detected by the photoelectric sensors within the fourth detection module. Optionally, the first reflective layer between the sides of the scintillation crystals adjacent to the second and third detection modules may include one or more third light-transmitting windows 630. Thus, visible light photons generated in the third detection module may pass through the second detection module and reach the first detection module, where they can be detected by the photoelectric sensor; or they may reach the fourth detection module and be detected by the photoelectric sensor there. Similarly, visible light photons generated in the second detection module may pass through the third detection module and reach the fourth detection module, where they can be detected by the photoelectric sensor; or they may reach the first detection module and be detected by the photoelectric sensor there. Therefore, the second and third detection modules may not include photoelectric sensors. Figure 3 The detector shown saves 75% of photoelectric sensors.

[0061] exist Figure 3 In this embodiment, detection modules with photoelectric sensors, such as the first and fourth detection modules, can be referred to as primary detection modules. For clarity, the first and fourth detection modules can be further distinguished as first-level detection modules and second-level detection modules. Detection modules without photoelectric sensors, such as the second and third detection modules, can be referred to as secondary detection modules. Although each detector includes four detection modules in the illustrated embodiment, in other embodiments not shown, it may include one primary detection module and one secondary detection module; or it may include two primary detection modules and one or more secondary detection modules; or it may include one primary detection module and multiple secondary detection modules. Furthermore, although the secondary detection modules are located between the primary detection modules in the illustrated embodiment, in other embodiments not shown, the secondary detection modules may be located on one or both sides of the primary detection modules.

[0062] As long as visible light photons in the scintillation crystal of the secondary detection module can be conducted to the optical path of the primary detection module, such that visible light photons in any scintillation crystal of the secondary detection module can be conducted to at least two optical sensors, the position and / or depth information of the scintillation crystal where the event occurred can be decoded. The at least two optical sensors include optical sensors in the first and / or second primary detection modules. For example, visible light photons in one scintillation crystal of the secondary detection module can be detected by at least two photoelectric sensors in the first primary detection module; or by at least two photoelectric sensors in the second primary detection module; or by a total of at least two photoelectric sensors in both the first and second primary detection modules.

[0063] Optionally, at least some adjacent secondary detection modules may not have transparent windows, so that visible light photons within the scintillation crystal of the secondary detection module can only be detected by at least two photoelectric sensors in one side of the secondary detection module. For example, in Figure 3 Based on this, the third light-transmitting window 630 can be removed. Visible light photons within each scintillation crystal of the second detection module can be detected by the photoelectric sensor of the first detection module, and visible light photons within each scintillation crystal of the third detection module can be detected by the photoelectric sensor of the fourth detection module.

[0064] In the illustrated embodiment, a light-transmitting window is provided between any pair of adjacent scintillation crystals between the two detection modules. For example, a second light-transmitting window 621 is provided between each pair of scintillation crystals between the first and second detection modules; a second light-transmitting window 622 is provided between each pair of scintillation crystals between the third and fourth detection modules; and a third light-transmitting window 630 is provided between each pair of scintillation crystals between the second and third detection modules. However, in other embodiments not shown, a second light-transmitting window 621 may not be provided between some pairs of scintillation crystals between the first and second detection modules; and / or a second light-transmitting window 622 may not be provided between some pairs of scintillation crystals between the third and fourth detection modules; and a third light-transmitting window 630 may not be provided between some pairs of scintillation crystals between the second and third detection modules.

[0065] For example, a light-transmitting window is provided between adjacent scintillation crystals within the secondary detection module. To distinguish it from the light-transmitting window mentioned above, this is referred to as the third light-transmitting window 630. Figure 3In the illustrated embodiment, each pair of adjacent scintillation crystals within the secondary detection module is provided with a third light-transmitting window 630 to form an optical path through all the scintillation crystals within the secondary detection module. In other embodiments not shown, the third light-transmitting window 630 may be provided between some adjacent scintillation crystals, or it may not be provided at all. With proper arrangement of the second and third light-transmitting windows, it is sufficient to ensure that visible light photons within each scintillation crystal of the secondary detection module can be detected by at least two photoelectric sensors within the detector.

[0066] For the primary detection module, the multiple photoelectric sensors included are arranged in a predetermined path corresponding to a portion of the scintillation crystals, such that the projections of the multiple photoelectric sensors included in the primary detection module onto the first end faces 310 of the multiple scintillation crystals only cover a portion of the first end faces 310 of these scintillation crystals. This reduces the number of photoelectric sensors required.

[0067] For example, the photoelectric sensor may correspond to a set of scintillation crystals, and the first end face of each of these scintillation crystals is coupled to the corresponding photoelectric sensor, for example... Figure 1 The embodiments shown, and those mentioned below Figure 6 and Figure 8 The illustrated embodiment. Each of these scintillation crystals can be coupled to a corresponding photoelectric sensor.

[0068] For example, each scintillation crystal in the detection module can be coupled to a photodetector, such that at least a portion of adjacent scintillation crystals are co-coupled to the same photodetector, such as those mentioned below. Figure 5 and Figure 7 The embodiments shown are illustrated. In these embodiments, each photodetector is coupled to multiple scintillation crystals, for example, each photodetector is coupled to two scintillation crystals, and each scintillation crystal is coupled to only one photodetector. In other embodiments not shown, some photodetectors may be coupled to two or more scintillation crystals, while other photodetectors may be coupled to only one scintillation crystal.

[0069] When the detector includes a secondary detection module, the secondary detection module can be used in conjunction with the primary detection module. Since the secondary detection module does not include a photoelectric sensor, the amount of photoelectric sensor used in the detector can be further reduced.

[0070] The second and third light-transmitting windows can have the same optical properties as the first light-transmitting window, and the scintillation crystal in the secondary detection module has the same optical properties as the scintillation crystal in the primary detection module. Therefore, based on the method provided above, reaction position decoding and reaction depth decoding can be performed.

[0071] Specifically, based on the photon intensity received by multiple photodetectors in the same detection module and the photon transmittance of the transmission windows, the number of transmission windows through which visible light photons pass to reach each of the multiple photodetectors can be determined, thereby decoding the location of the event occurring in the scintillation crystal. Furthermore, based on the photon intensity and the length of a single scintillation crystal, the total length of the scintillation crystal through which visible light photons pass to reach each of the multiple photodetectors can be determined, thereby decoding the reaction depth within the scintillation crystal where the event occurs. If reaction depth decoding is required, it can be performed after reaction location decoding; that is, after determining which scintillation crystal the event occurred in, the reaction depth within that scintillation crystal is then decoded.

[0072] According to another aspect of the present invention, an emission imaging apparatus is provided. The emission imaging apparatus may include a processor module and any of the detectors described above. Multiple photoelectric sensors may be electrically connected to the processor module, respectively. The processor module is used to perform the various decodings described above. Exemplarily, the detectors may be arranged in a detector ring. Typically, the multiple detectors forming the detector ring have substantially the same structure. However, this application does not exclude embodiments where different detectors are used to form the detector ring. Multiple detector rings may be closely arranged along a direction perpendicular to the plane of the paper. The detection space enclosed by these detector rings can accommodate the object to be measured. Typically, the detection space may be substantially cylindrical. Of course, this application does not exclude embodiments where the detection space has other shapes. Multiple detectors may be arranged in pairs, and the paired detectors can function under PET imaging. In embodiments where the emission imaging apparatus is a SPECT device, the detectors may be arranged in a detector plate. Each detector plate may include one detector, or multiple detectors arranged in a matrix.

[0073] exist Figure 1-3 In the illustrated embodiment, each photodetector is coupled to only one scintillation crystal. In other embodiments, a photodetector may be coupled to two or more scintillation crystals simultaneously. Figure 5 In the illustrated embodiment, the light-receiving surface of each photodetector can be coupled to the first end face 310 of a plurality of scintillation crystals. A portion of the first end face 310 of each scintillation crystal is coupled to the photodetector. Compared to Figure 1 In the embodiment shown, since the visible light photons generated in each scintillation crystal can directly reach one of the photoelectric sensors without being attenuated by the transmission window, the photoelectric sensor detects a greater intensity of photons, which ultimately results in a higher signal-to-noise ratio for the detection component.

[0074] For example, such as Figure 5As shown, a portion of the first end face 310 of each of the first scintillation crystals C1 and C3 is covered by a third reflective layer 530. The uncovered portions of the first end faces 310 of both the first scintillation crystals C1 and C3 form a first coupling opening. The first scintillation crystals C1 and C3 are coupled to the first photodetector S1 through the first coupling opening. A portion of the first end face 310 of each of the second scintillation crystals C2 and C4 is covered by the third reflective layer 530. The uncovered portions of the first end faces 310 of both the second scintillation crystals C2 and C4 form a second coupling opening. The second scintillation crystals C2 and C4 are coupled to the second photodetector S2 through the second coupling opening. Thus, the light-receiving surface of the photodetector can have a shape adapted to the coupling opening of the scintillation crystal to prevent visible light photons from leaking to the outside. When an event occurs inside the scintillation crystal, the generated visible light photons can reach the coupling opening, and those with the appropriate angle can reach the light-receiving surface of the photodetector. Visible light photons illuminating the third reflective layer 530 are reflected by the third reflective layer 530 and reach the first reflective layer 510 and the second reflective layer 520. A portion of these photons undergoes multiple reflections and reaches the first light-transmitting window and the coupling opening, respectively. It should be noted that, for ease of understanding, it is assumed here that all visible light photons illuminating the light-receiving surface of the photoelectric sensor are absorbed.

[0075] In another set of embodiments, see Figure 6, the detection module includes a first scintillation crystal C1, a second scintillation crystal C2, and a fifth scintillation crystal C5 located between them along a predetermined arrangement path, and also includes a first photoelectric sensor S1 and a second photoelectric sensor S2. A first light-transmitting window 611 is provided between the first scintillation crystal C1 and the fifth scintillation crystal C5, and a first light-transmitting window 612 is provided between the fifth scintillation crystal C5 and the second scintillation crystal C2. Thus, an optical path passing through three scintillation crystals and two first light-transmitting windows is formed. The first end face 310 of the first scintillation crystal C1 is coupled to the first photoelectric sensor S1, and the first end face 310 of the second scintillation crystal C2 is coupled to the second photoelectric sensor S2. When an event occurs in the first scintillation crystal C1, most of the generated visible light photons are detected by the first photoelectric sensor S1, and a small part is detected by the second photoelectric sensor S2. When an event occurs in the fifth scintillation crystal C5, the photon intensities detected by the first photoelectric sensor S1 and the second photoelectric sensor S2 are equivalent. When an event occurs in the second scintillation crystal C2, most of the generated visible light photons are detected by the second photoelectric sensor S2, and a small part is detected by the first photoelectric sensor S1. For ease of understanding, assume that the photon transmittance of each first light-transmitting window is k (0 < k < 1), and the attenuation of visible light photons by the scintillation crystal is ignored. If an event occurs in the first scintillation crystal C1, the relationship between the photon intensity detected by the first photoelectric sensor S1 and the photon intensity detected by the second photoelectric sensor S2 is S2 / S1 = k 2 ; if an event occurs in the second scintillation crystal C2, then S2 / S1 = 1; if an event occurs in the fifth scintillation crystal C5, then S1 / S[2 = k 2 .

[0076] Exemplarily, continue to refer to Figure 6 , the first light-transmitting window 611 in the first reflection layer 510 between the first scintillation crystal C1 and the fifth scintillation crystal C5 is adjacent to the second end face 320; and the first light-transmitting window 612 in the first reflection layer 510 between the second scintillation crystal C2 and the fifth scintillation crystal C5 is also adjacent to the second end face 320.

[0077] Assume the length of each scintillation crystal is L. For ease of understanding, ignore the attenuation of visible light photons by the first transparent window itself, the size of the first transparent window, and the width of the scintillation crystal, and assume that the attenuation of visible light photons by the scintillation crystal is uniform. If the event occurs in the middle of the first scintillation crystal C1, then the relationship between the photon intensity detected by the first photodetector S1 and the photon intensity detected by the second photodetector S2 is as follows: the visible light photons reaching the first photodetector S1 are attenuated by approximately 0.5L of scintillation crystal length, and the visible light photons reaching the second photodetector S2 are attenuated by approximately 1.5L of scintillation crystal length. If the event occurs within the first scintillation crystal C1 at a position adjacent to the second end face 320, then the visible light photons reaching the first photodetector S1 are attenuated by approximately 1L of scintillation crystal length, and the visible light photons reaching the second photodetector S2 are attenuated by approximately 1L of scintillation crystal length. In other words, since the first light-transmitting window is located near the second end face 320, it is equivalent to aligning the second end faces 320 of the first scintillation crystal C1 and the second scintillation crystal C2, thereby determining the DOI of the event based on the attenuation of visible light photons. If the event occurs in the fifth scintillation crystal C5, the intensity of visible light photons detected by the first photoelectric sensor S1 and the second photoelectric sensor S2 is the same. As the DOI increases, the farther away from the second end face 320, the fewer visible light photons reach the two photoelectric sensors through the first light-transmitting windows on both sides. Therefore, the DOI can be determined by the specific values ​​of the photon intensities detected by the two photoelectric sensors, rather than by the ratio of the photon intensities detected by the two photoelectric sensors. If the event occurs in the fifth scintillation crystal C5 at a position adjacent to the first end face 310, the visible light photons reaching the first photoelectric sensor S1 and the second photoelectric sensor S2 are both attenuated by a 2L length of scintillation crystal; conversely, if the event occurs in the fifth scintillation crystal C5 at a position adjacent to the second end face 320, the visible light photons reaching the first photoelectric sensor S1 and the second photoelectric sensor S2 are both attenuated by a 1L length of scintillation crystal. If the photon intensities detected by the first photoelectric sensor S1 and the second photoelectric sensor S2 are the same, it can be determined that the event occurred within the fifth scintillation crystal C5. As the DOI increases, the photon intensities detected by the first photoelectric sensor S1 and the second photoelectric sensor S2 decrease. Figure 6 In the embodiment shown, one-third of the photoelectric sensor is saved.

[0078] In the various embodiments described above, the light-receiving surface of the photoelectric sensor can be directly coupled to the first end face 310 of the scintillation crystal 300, for example... Figure 1 and Figure 5 The example shown. In Figure 1In the illustrated embodiment, the first photoelectric sensor S1 is coupled only to the first scintillation crystal C1, and the second photoelectric sensor S2 is coupled only to the second scintillation crystal C2. However... Figure 5 In the illustrated embodiment, the first photoelectric sensor S1 is coupled to both the first scintillation crystal C1 and the third scintillation crystal C3, and the second photoelectric sensor S2 is coupled to both the second scintillation crystal C2 and the fourth scintillation crystal C4. However, in Figure 7 In the illustrated embodiment, the photoelectric sensor can be coupled to the scintillation crystal via a light guide. Specifically, the first photoelectric sensor S1 is coupled to the first scintillation crystal C1 and the third scintillation crystal C3 via a light guide, and the second photoelectric sensor S2 is coupled to the second scintillation crystal C2 and the fourth scintillation crystal C4 via another light guide. The following section will discuss... Figure 7 The proposed scheme will be described further.

[0079] For the embodiments illustrated above, when the event occurs in the first scintillation crystal C1, most of the generated visible light photons are detected by the first photoelectric sensor S1, and a small portion are detected by the second photoelectric sensor S2. When the event occurs in the third scintillation crystal C3, most of the generated visible light photons are detected by the first photoelectric sensor S1, and a small portion are detected by the second photoelectric sensor S2. The second scintillation crystal C2 + the fourth scintillation crystal C4 is symmetrical to the first scintillation crystal C1 + the third scintillation crystal C3, therefore the same applies when the event occurs in the second scintillation crystal C2 and the fourth scintillation crystal C4. It should be noted that when the event occurs in the third scintillation crystal C3, since the first light-transmitting window that needs to be passed through to reach the second photoelectric sensor S2 is shorter, the photon intensity detected by the second photoelectric sensor S2 is greater than the photon intensity detected by the second photoelectric sensor S2 when the event occurs in the first scintillation crystal C1.

[0080] for Figure 1 In the illustrated embodiment, the first light-transmitting window 611 in the first reflective layer 510 between the first scintillation crystal C1 and the third scintillation crystal C3 is adjacent to the second end face 320; the first light-transmitting window 613 in the first reflective layer 510 between the second scintillation crystal C2 and the fourth scintillation crystal C4 is adjacent to the second end face 320; and the first light-transmitting window 612 in the first reflective layer 510 between the third scintillation crystal C3 and the fourth scintillation crystal C4 is adjacent to the first end face 310. The method for determining the DOI (Domain of Interest) of an event in the scintillation crystal through the photon intensity relationship detected by the first photoelectric sensor S1 and the second photoelectric sensor S2 has already been described above. Therefore, it will not be repeated here.

[0081] for Figure 5 and Figure 7In the illustrated embodiment, the first end face 310 of the first scintillation crystal C1 and the first end face 310 of the third scintillation crystal C3 are jointly coupled to the first photoelectric sensor S1, and the first end face 310 of the second scintillation crystal C2 and the first end face 310 of the fourth scintillation crystal C4 are jointly coupled to the second photoelectric sensor S2. The first light-transmitting window 611 in the first reflective layer 510 between the first scintillation crystal C1 and the third scintillation crystal C3 is adjacent to the second end face 320; the first light-transmitting window 613 in the first reflective layer 510 between the second scintillation crystal C2 and the fourth scintillation crystal C4 is adjacent to the second end face 320; and the first light-transmitting window 612 in the first reflective layer 510 between the third scintillation crystal C3 and the fourth scintillation crystal C4 is adjacent to the first end face 310.

[0082] The DOI method for determining that an event occurs in a scintillation crystal is as follows: The attenuation of the first transmission window is still ignored, and it is assumed that the attenuation of visible light photons by the scintillation crystal (length L) is linear. Assuming the event occurs at the exact center of the first scintillation crystal C1, the visible light photons reaching the first photodetector S1 include a first portion attenuated by a 0.5L length scintillation crystal, and a second portion attenuated by a 1.5L length scintillation crystal (this second portion passes through the first transmission window 611 and reaches the third scintillation crystal C3, where it is detected by the first photodetector S1). Specifically, for the visible light photons reaching the first photodetector S1: the first portion of the visible light photons is attenuated by half of the first scintillation crystal C1, and the second portion is attenuated by half of the first scintillation crystal C1 and the entire third scintillation crystal C3. Furthermore, the visible light photons may also travel along the optical path to the fourth scintillation crystal C4 and the second scintillation crystal C2. Therefore, the visible light photons reaching the second photodetector S2 include a first portion attenuated by a 1.5L length scintillation crystal, and a second portion attenuated by a 3.5L length scintillation crystal. In other words, for visible light photons reaching the second photodetector S2: the first portion of the visible light photons is attenuated by half of the first scintillation crystal C1 and the entire third scintillation crystal C3. The second portion of the visible light photons is attenuated by half of the first scintillation crystal C1, the entire third scintillation crystal C3, the entire fourth scintillation crystal C4, and the entire second scintillation crystal C2. The first and second portions of the visible light photons received by the first photodetector S1 and the second portion of the visible light photons received by the second photodetector S2 can be added together. Therefore, based on the photon intensity relationship received by the first photodetector S1 and the second photodetector S2, the DOI (Domain of Interest) where the event occurred in the scintillation crystal can be determined.

[0083] When it is assumed that the event occurs at a position adjacent to the second end face 320 within the first scintillation crystal C1, the visible light photons reaching the first photoelectric sensor S1 include a first part attenuated by the scintillation crystal with a length of 1L and a second part attenuated by the scintillation crystal with a length of 1L. The visible light photons reaching the second photoelectric sensor S2 include a first part attenuated by the scintillation crystal with a length of 1L and a second part attenuated by the scintillation crystal with a length of 3L.

[0084] When it is assumed that the event occurs at the middle position of the third scintillation crystal C3, the visible light photons reaching the first photoelectric sensor S1 include a first part attenuated by the scintillation crystal with a length of 0.5L and a second part attenuated by the scintillation crystal with a length of 1.5L. The visible light photons reaching the second photoelectric sensor S2 include a first part attenuated by the scintillation crystal with a length of 0.5L and a second part attenuated by the scintillation crystal with a length of 2.5L. In short, by analogy, the DOI where the event occurs within each first scintillation crystal can be determined inversely based on the relationship between the photon intensities detected by the first photoelectric sensor S1 and the second photoelectric sensor S2.

[0085] In Figure 7 In the illustrated embodiment, the first reflective layer 510 does not extend into the light guide to avoid affecting the determination of DOI.

[0086] As Figure 8 As shown, exemplarily, the first end face 310 of the third scintillation crystal C3 is coupled to the first photoelectric sensor S1, and the first end face 310 of the fourth scintillation crystal C4 is coupled to the second photoelectric sensor S2. When performing reaction position decoding, the photon transmittance of each first light-transmitting window is k (0 < k < 1). If the photon intensity detected by the first photoelectric sensor S1 is much greater than that detected by the second photoelectric sensor S2, then the event is located in the first scintillation crystal C1; if the photon intensity detected by the first photoelectric sensor S1 is greater than that detected by the second photoelectric sensor S2, then the event is located in the third scintillation crystal C3. Due to symmetry, if the photon intensity detected by the first photoelectric sensor S1 is less than that detected by the second photoelectric sensor S2, then the event is located in the fourth scintillation crystal C4; if the photon intensity detected by the first photoelectric sensor S1 is much less than that detected by the second photoelectric sensor S2, then the event is located in the second scintillation crystal C2. The much greater and greater mentioned above mean that when the event occurs in the first scintillation crystal C1, the difference or ratio between the photon intensity detected by the first photoelectric sensor S1 and the photon intensity detected by the second photoelectric sensor S2 is within the first interval range, and when the event occurs in the second scintillation crystal C2, the difference or ratio between the photon intensity detected by the first photoelectric sensor S1 and the photon intensity detected by the second photoelectric sensor S2 is within the second interval range, and the lower limit of the first interval range is greater than the upper limit of the second interval range. The relationship of much less than and less than is similar.

[0087] For example, for Figure 8 In the illustrated embodiment, the first light-transmitting window in the first reflective layer 510 between the first scintillation crystal C1 and the third scintillation crystal C3 includes a first sub-window 611a adjacent to the first end face 310 and a second sub-window 611b adjacent to the second end face 320. The first light-transmitting window in the first reflective layer 510 between the second scintillation crystal C2 and the fourth scintillation crystal C4 includes a third sub-window 613a adjacent to the first end face 310 and a fourth sub-window 613b adjacent to the second end face 320. The first light-transmitting window 612 between the third scintillation crystal C3 and the fourth scintillation crystal C4 is adjacent to the first end face 310. To further improve the signal-to-noise ratio, two first light-transmitting windows are provided between the first scintillation crystal C1 and the second scintillation crystal C2, which allows visible light photons generated within the first scintillation crystal C1 to experience less attenuation when passing through the first light-transmitting window to reach the first photoelectric sensor S1. The DOI can be determined in a manner that ignores the attenuation generated by the light-transmitting window 600 itself.

[0088] Assuming the event occurs at the exact center of the first scintillation crystal C1, the photon intensity detected by the first photodetector S1 is as follows: visible light photons are attenuated by the 0.5L length of the first scintillation crystal C1, pass through the first sub-window, and reach the first photodetector S1; visible light photons are simultaneously attenuated by the 0.5L length of the first scintillation crystal C1, the second sub-window, and the 1L length of the third scintillation crystal C3 before reaching the first photodetector S1; a portion of the visible light photons enters the third scintillation crystal C3 through the second sub-window, and then passes through the third scintillation crystal C3, the first sub-window, the first scintillation crystal C1, and the second sub-window before reaching the first photodetector S1. Therefore, the photon intensity reaching the first photodetector S1 is complex. In other words, a circular optical path may be formed: first scintillation crystal C1 → second sub-window → third scintillation crystal C3 → first sub-window → first scintillation crystal C1 → second sub-window. The photon intensity detected by the second photodetector S2 includes the first portion attenuated by the 1.5L length scintillation crystal, and the second portion. Similarly, the visible light photon path in the second part is as follows: Part of the visible light photons from the third scintillation crystal C3 passes through the fourth scintillation crystal C4, then through the first light-transmitting window of the fourth scintillation crystal C4 adjacent to the second end face 320, reaching the second scintillation crystal C2. The other part passes through the first light-transmitting window of the fourth scintillation crystal C4 adjacent to the first end face 310, reaching the second scintillation crystal C2, then through the second scintillation crystal C2, reaching the first light-transmitting window of the second scintillation crystal C2 adjacent to the second end face 320, and returning to the fourth scintillation crystal C4. This results in a more complex intensity distribution of the visible light photons in the second part, but the visible light photons in the second part are attenuated by approximately 3.5L of scintillation crystal.

[0089] From another perspective, since the attenuation of visible light photons by the first light-transmitting window itself is ignored, when the event occurs at the first end of any crystal, the photon intensities detected by the first photoelectric sensor S1 and the second photoelectric sensor S2 are at their maximum, while when the event occurs at the second end of the crystal, the photon intensities detected by the first photoelectric sensor S1 and the second photoelectric sensor S2 are at their minimum. In actual experiments, because both the attenuation of visible light photons by the first light-transmitting window and the attenuation of visible light photons by the scintillating crystal exist simultaneously, the photon intensities detected by the first photoelectric sensor S1 and the second photoelectric sensor S2, as well as the relationship between their photon intensities, are different at any position of any scintillating crystal where the event occurs. This allows for the determination of the scintillating crystal where the event occurs and its DOI (Domain of Interest).

[0090] For example, refer back Figure 7The first end face 310 of the first scintillation crystal C1 and the first end face 310 of the third scintillation crystal C3 are coupled to the first photodetector S1 via a tapered first light guide 710, and the first end face 310 of the second scintillation crystal C2 and the first end face 310 of the fourth scintillation crystal C4 are coupled to the second photodetector S2 via a tapered second light guide 720. The first light guide 710 and the second light guide 720 may be made of glass, and the light guides have an incident light surface and an exit light surface. In some embodiments, a reflective layer may also be provided on the first light guide 710 and the second light guide 720 to prevent visible light photons from leaking from the light guides. In other embodiments, visible light photons entering via the incident light surface may undergo total internal reflection inside the light guide and can only exit through the exit light surface. The total area of ​​the first end faces 310 of the first scintillation crystal C1 and the third scintillation crystal C3 can be larger than the area of ​​the light-receiving surface of the first photoelectric sensor S1. If, as described in the above embodiment, the first end face 310 of each scintillation crystal is only partially coupled to the first photoelectric sensor S1, then visible light photons reaching other parts of the first end face 310 will need to undergo more reflections before finally reaching the first photoelectric sensor S1. This will cause some visible light photons to be severely attenuated, reducing the signal-to-noise ratio of the detection module. However, by providing a first light guide 710, the light-incident surface of the first light guide 710 can be configured to match the shape of the first end face 310, thereby preventing visible light photons generated by the scintillation crystal from leaking to the outside. Visible light photons entering the first light guide 710 can be transmitted and coupled to the first photoelectric sensor S1 with almost no loss. Similarly, the light-exit surface of the first light guide 710 can also be configured to match the light-receiving surface of the photoelectric sensor. The function and principle of the second light guide 720 are the same as those of the first light guide 710, and will not be described again here. In summary, regardless of the size relationship between the first end face 310 of the scintillation crystal and the light receiving surface of the photoelectric sensor, a reasonably designed light guide can transmit light from one or more first end faces 310 to the light receiving surface with low loss, and prevent light from leaking from the first end face 310 or the photoelectric sensor to the outside.

[0091] Continue to refer to Figure 7In some embodiments, visible light photons generated in the first scintillation crystal C1 can reach the third scintillation crystal C3 through the first light guide 710, and then reach the fourth scintillation crystal C4 through the first light-transmitting window between the third scintillation crystal C3 and the fourth scintillation crystal C4, finally reaching the second photoelectric sensor S2. In this case, the method for determining the location of the event based on the photon intensity difference between the first photoelectric sensor S1 and the second photoelectric sensor S2 may differ, and it is necessary to further consider the attenuation of visible light photons as they travel through the light guide to the adjacent scintillation crystals. In other embodiments, visible light photons generated in the first scintillation crystal C1 or the third scintillation crystal C3, after entering the first light guide 710, will not travel through the light guide to the adjacent scintillation crystals, but will only reach the first photoelectric sensor S1.

[0092] According to another aspect of the present invention, a method for decoding a detection module is also provided. The method includes:

[0093] Based on the photon intensity received by at least two photoelectric sensors in the detection module and the photon transmittance of the light-transmitting window, the location of the scintillation crystal where the decoding event occurred is determined; and

[0094] Based on the photon intensity received by the at least two photoelectric sensors and the length of a single scintillation crystal, the total length of the scintillation crystal through which visible light photons pass to reach the at least two photoelectric sensors is determined, thereby decoding the reaction depth within the scintillation crystal where the event occurs.

[0095] In one specific embodiment, the scintillation crystal and photoelectric sensor, such as Figure 1 The arrangement is shown. Based on the analysis above, the specific method for decoding the reaction positions is as follows:

[0096] Define decoding factor R :

[0097]

[0098] in, S1 The intensity of photons received by the first photoelectric sensor S1 S2 The intensity of the photons received by the second photoelectric sensor S2.

[0099] Assuming the photon transmittance of each light-transmitting window is... k The number of visible light photons generated by the scintillation crystal receiving gamma photons is I .

[0100] Based on the following relationship, the event is determined to be located in the first scintillation crystal C1:

[0101] ≈

[0102] Based on the following relationship, the event is determined to be located in the third scintillation crystal C3:

[0103] ≈

[0104] Based on the following relationship, the event is determined to be located in the fourth scintillation crystal C4:

[0105] ≈

[0106] Based on the following relationship, the event is determined to be located in the second scintillation crystal C2:

[0107] ≈

[0108] The specific method for performing DOI decoding is as follows:

[0109] Define the DOI calculation factors for the first scintillation crystal C1 and the third scintillation crystal C3. h :

[0110]

[0111] DOI is calculated using the centroid method when... h When →1, the location of the event approaches the first photoelectric sensor S1; when h →-1 (that is, h When the value approaches -1, the event location approaches the second photoelectric sensor S2; h When →0, the event location is between the third scintillation crystal C3 and the fourth scintillation crystal C4. Due to symmetry, the following relationship is used between the fourth scintillation crystal C4 and the second scintillation crystal C2:

[0112]

[0113] To keep the DOI calculation factor positive.

[0114] Based on the following relationships, the DOIs of events located within the first scintillation crystal C1, the second scintillation crystal C2, the third scintillation crystal C3, and the fourth scintillation crystal C4 are determined:

[0115]

[0116] in, L The length of each scintillation crystal.

[0117] In another specific embodiment, the scintillation crystal and photoelectric sensor are as follows: Figure 6The arrangement is shown. Based on the analysis above, the specific method for decoding the reaction positions is as follows:

[0118] Define decoding factor R :

[0119]

[0120] in, S1 The intensity of photons received by the first photoelectric sensor S1 S2 The intensity of the photons received by the second photoelectric sensor S2.

[0121] Assuming the photon transmittance of each light-transmitting window is... k The number of visible light photons generated by the scintillation crystal receiving gamma photons is I .

[0122] Based on the following relationship, the event is determined to be located in the first scintillation crystal C1:

[0123] ≈

[0124] Based on the following relationship, the event is determined to be located in the fifth scintillation crystal C5:

[0125] ≈

[0126] Based on the following relationship, the event is determined to be located in the second scintillation crystal C2:

[0127] ≈

[0128] The specific method for performing DOI decoding is as follows:

[0129] Define the DOI calculation factor for the first scintillation crystal C1. h :

[0130]

[0131] DOI is calculated using the centroid method when... h When →1, the event location approaches the first photoelectric sensor S1; when h When the value is -1, the event location approaches the second photoelectric sensor S2; h When the value is →0, the event location is in the fifth scintillation crystal C5. Due to symmetry, the calculation factor is kept positive in the second scintillation crystal C2. The DOI calculation factor of the second scintillation crystal C2... h 'as follows:

[0132]

[0133] The DOI of the event located within the first scintillation crystal C1 is determined based on the following relationship:

[0134]

[0135] The DOI of the event located within the second scintillation crystal C2 is determined based on the following relationship:

[0136]

[0137] If the event occurs at the fifth scintillation crystal C5, as the DOI increases and the distance from the top increases, the number of visible light photons passing through the light-transmitting layers on both sides to reach the sensors at both ends decreases simultaneously. Therefore, the DOI can be... S 1+ S 2 represents the attenuation of the total number of visible light photons.

[0138] The DOI of the event located within the fifth scintillation crystal C5 is determined based on the following relationship:

[0139]

[0140] in S 1 max and S 2 max When the event occurs at the very center of the light path, i.e., at the top of the fifth scintillation crystal C5, the first photoelectric sensor... S 1 and the maximum detection value of the second photoelectric sensor S2.

[0141] In yet another specific embodiment, the scintillation crystal and photoelectric sensor are as follows: Figure 8 The arrangement is shown. Based on the analysis above, the specific method for decoding the reaction positions is as follows:

[0142] based on S1 ≫ S2 The event was determined to be located in the first scintillation crystal C1;

[0143] based on S1 > S2 The event was determined to be located in the third scintillation crystal C3;

[0144] based on S1 < S2 The event was determined to be located in the fourth scintillation crystal C4;

[0145] based on S1 ≪ S2 The event was determined to be located in the second scintillation crystal C2;

[0146] in, S1S1 represents the photon intensity received by the first photoelectric sensor S1, and S2 represents the photon intensity received by the second photoelectric sensor S2.

[0147] The DOI decoding of the first scintillation crystal C1 and the second scintillation crystal C2 can be performed experimentally based on the specific values ​​of S1 / S2, using the electrical signals generated by the first photoelectric sensor S1 and the second photoelectric sensor S2.

[0148] If the event occurs at the third scintillation crystal C3 or the fourth scintillation crystal C4, as the DOI increases and the distance from the top decreases, the number of visible light photons passing through the light-transmitting layers on both sides and reaching the sensors at both ends will decrease simultaneously. Therefore, the DOI can be... S 1+ S 2 represents the attenuation of the total number of visible light photons. Therefore, the DOI (Discretionary Opinion) of the event located within the third scintillation crystal C3 and the fourth scintillation crystal C4 can be determined based on the following relationship:

[0149] in S 1 max and S 2 max The first photoelectric sensor is activated when the event occurs at the very center of the optical path, for example, at the bottom of the third scintillation crystal C3 and the fourth scintillation crystal C4. S 1 and the second photoelectric sensor S 2. Maximum detection value.

[0150] In another specific embodiment, the scintillation crystal and photoelectric sensor are as follows: Figure 5 and Figure 7 The arrangement shown is given in the text. Based on the analysis above, the specific method for decoding the reaction positions is as follows:

[0151] Define decoding factor R :

[0152]

[0153] in, S1 The intensity of photons received by the first photoelectric sensor S1 S2 The intensity of the photons received by the second photoelectric sensor S2.

[0154] based on R ≫1, Explanation S1 ≫ S2 The event was determined to be located in the first scintillation crystal C1;

[0155] based on R →1 + (That is, the R value is close to 1 but always greater than 1), indicating S1 Slightly largerS2 The two are nearly balanced, but the signal center of gravity is slightly to the left, indicating that the event is located in the third scintillation crystal C3;

[0156] Due to symmetry,

[0157] based on R →1 - (That is, the R value is close to 1 but always less than 1), indicating S2 Slightly larger S1 The signal's center of gravity is slightly downward, confirming that the event is located in the fourth scintillation crystal C4;

[0158] based on R ≪1, Explanation S2 ≫ S1 The event was determined to be located in the second scintillation crystal C2.

[0159] The specific method for performing DOI decoding is as follows:

[0160] Define the DOI calculation factors for the first scintillation crystal C1 and the third scintillation crystal C3. h :

[0161]

[0162] DOI is calculated using the centroid method when... h When →1, the event location approaches the first photoelectric sensor S1; when h When the value is -1, the event location approaches the second photoelectric sensor S2; h When the value is →0, the event location is between the third scintillation crystal C3 and the fourth scintillation crystal C4. Due to symmetry, the following relationship is used in the fourth scintillation crystal C4 and the second scintillation crystal C2 to maintain a positive DOI calculation factor:

[0163]

[0164] The DOI of the event located within the first scintillation crystal C1 is determined based on the following relationship:

[0165]

[0166] in, L The length of each scintillation crystal.

[0167] The DOI of the event located within the second scintillation crystal C2 is determined based on the following relationship:

[0168]

[0169] If the event occurs at the third scintillation crystal C3 or the fourth scintillation crystal C4, as the DOI increases and the distance from the top increases, the number of visible light photons passing through the light-transmitting layers on both sides to reach the photodetector decreases simultaneously. Therefore, the DOI can be reduced by... S 1+ S 2 represents the attenuation of the total number of visible light photons. Therefore, the DOI (Domain of Interest) where the event is located within the third scintillation crystal C3 or the fourth scintillation crystal C4 can be determined based on the following relationship:

[0170]

[0171] in S 1 max and S 2 max The first photoelectric sensor is activated when the event occurs at the very center of the optical path, for example, at the bottom of the third scintillation crystal C3 and the fourth scintillation crystal C4. S 1 and the maximum detection value of the second photoelectric sensor S2.

[0172] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front", "rear", "up", "down", "left", "right", "horizontal", "vertical", "horizontal", "top", and "bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0173] For ease of description, relative terms such as "above," "over," "on the upper surface of," and "above" are used here to describe the regional positional relationship of one or more components or features shown in the figures to other components or features. It should be understood that relative terms include not only the orientation of the component as depicted in the figure but also different orientations during use or operation. For example, if the components in the figures are inverted as a whole, "above" or "above other components or features" will include cases where the component is "below" or "under" other components or features. Thus, the exemplary term "above" can include both "above" and "below." Furthermore, these components or features may also be positioned at other different angles (e.g., rotated 90 degrees or other angles), and this document intends to include all such cases.

[0174] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, parts, components, and / or combinations thereof.

[0175] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0176] The present invention has been described through the above embodiments. However, it should be understood that the above embodiments are for illustrative purposes only and are not intended to limit the invention to the scope of the described embodiments. Furthermore, those skilled in the art will understand that the present invention is not limited to the above embodiments, and many more variations and modifications can be made based on the teachings of the present invention, all of which fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A detection module, characterized in that, include: A plurality of scintillation crystals, each having a first end face, a second end face opposite to the first end face, and a side face connected between the first end face and the second end face, the plurality of scintillation crystals being arranged in an array with their side faces adjacent to each other along a predetermined arrangement path; A first reflective layer covers the sides of the plurality of scintillation crystals. The first reflective layer between any adjacent scintillation crystals on the predetermined arrangement path includes a light-transmitting window to form a light path through all the scintillation crystals on the predetermined arrangement path and the light-transmitting window. A plurality of photoelectric sensors, fewer in number than the plurality of scintillation crystals, are coupled to at least a portion of a first end face of the plurality of scintillation crystals, such that visible light photons within each of the plurality of scintillation crystals can be conducted to at least two of the plurality of photoelectric sensors via the optical path; as well as A second reflective layer covers the second end face of the plurality of scintillation crystals.

2. The detection module according to claim 1, characterized in that, The plurality of photoelectric sensors are arranged in a manner corresponding to a portion of the predetermined arrangement path, such that the projections of the plurality of photoelectric sensors onto the first end faces of the plurality of scintillation crystals only cover a portion of the first end faces of the plurality of scintillation crystals.

3. The detection module according to claim 2, characterized in that, The plurality of photoelectric sensors are configured corresponding to a portion of the plurality of scintillation crystals, and the first end face of each scintillation crystal in the portion of the plurality of scintillation crystals is coupled to the corresponding photoelectric sensor; or Each of the plurality of scintillation crystals is coupled to the photoelectric sensor such that at least a portion of adjacent scintillation crystals are co-coupled to the same photoelectric sensor.

4. The detection module according to claim 1, characterized in that, The plurality of scintillation crystals include a first scintillation crystal, a second scintillation crystal, and a third scintillation crystal and a fourth scintillation crystal located between the two along the predetermined arrangement path. The third scintillation crystal is adjacent to the first scintillation crystal, and the fourth scintillation crystal is adjacent to the second scintillation crystal. The plurality of photoelectric sensors include a first photoelectric sensor and a second photoelectric sensor, wherein: The first end face of the first scintillation crystal is coupled to the first photodetector, and the first end face of the second scintillation crystal is coupled to the second photodetector; and / or The first end face of the third scintillation crystal is coupled to the first photoelectric sensor, and the first end face of the fourth scintillation crystal is coupled to the second photoelectric sensor.

5. The detection module according to claim 4, characterized in that, When the first end face of the first scintillation crystal is coupled to the first photoelectric sensor, and the first end face of the second scintillation crystal is coupled to the second photoelectric sensor: The light-transmitting window in the first reflective layer between the first scintillation crystal and the third scintillation crystal is adjacent to the second end face; the light-transmitting window in the first reflective layer between the second scintillation crystal and the fourth scintillation crystal is adjacent to the second end face; and the light-transmitting window in the first reflective layer between the third scintillation crystal and the fourth scintillation crystal is adjacent to the first end face.

6. The detection module according to claim 4, characterized in that, When the first end face of the third scintillation crystal is coupled to the first photodetector, and the first end face of the fourth scintillation crystal is coupled to the second photodetector: The light-transmitting window in the first reflective layer between the first scintillation crystal and the third scintillation crystal includes a first sub-window adjacent to the first end face and a second sub-window adjacent to the second end face. The light-transmitting window in the first reflective layer between the second scintillation crystal and the fourth scintillation crystal includes a third sub-window adjacent to the first end face and a fourth sub-window adjacent to the second end face. The light-transmitting window between the third scintillation crystal and the fourth scintillation crystal is adjacent to the first end face.

7. The detection module according to claim 4, characterized in that, When the first end face of the first scintillation crystal and the first end face of the third scintillation crystal are both coupled to the first photoelectric sensor, and the first end face of the second scintillation crystal and the first end face of the fourth scintillation crystal are both coupled to the second photoelectric sensor: The light-transmitting window in the first reflective layer between the first scintillation crystal and the third scintillation crystal is adjacent to the second end face; the light-transmitting window in the first reflective layer between the second scintillation crystal and the fourth scintillation crystal is adjacent to the second end face; and the light-transmitting window in the first reflective layer between the third scintillation crystal and the fourth scintillation crystal is adjacent to the first end face.

8. The detection module according to claim 7, characterized in that, A portion of the first end face of each of the first and third scintillation crystals is covered with a third reflective layer, and the uncovered portions of the first end faces of both the first and third scintillation crystals form a first coupling opening, through which the first and third scintillation crystals are coupled to the first photoelectric sensor. A portion of the first end face of each of the second and fourth scintillation crystals is covered with a third reflective layer, and the uncovered portions of the first end faces of both the second and fourth scintillation crystals form a second coupling opening, through which the second and fourth scintillation crystals are coupled to the second photoelectric sensor.

9. The detection module according to claim 7, characterized in that, The first end face of the first scintillation crystal and the first end face of the third scintillation crystal are coupled to the first photoelectric sensor through a tapered first light guide. The first end face of the second scintillation crystal and the first end face of the fourth scintillation crystal are coupled to the second photoelectric sensor through a tapered second light guide.

10. The detection module according to claim 1, characterized in that, The plurality of scintillation crystals includes a first scintillation crystal, a second scintillation crystal, and a fifth scintillation crystal located between the two along the predetermined arrangement path; the plurality of photoelectric sensors includes a first photoelectric sensor and a second photoelectric sensor. The first end face of the first scintillation crystal is coupled to the first photoelectric sensor, and the first end face of the second scintillation crystal is coupled to the second photoelectric sensor.

11. The detection module according to claim 10, characterized in that, The light-transmitting windows in the first reflective layer between the first scintillation crystal and the fifth scintillation crystal are both adjacent to the second end face; and The light-transmitting window in the first reflective layer between the second scintillation crystal and the fifth scintillation crystal is adjacent to the second end face.

12. The detection module according to claim 1, characterized in that, The predetermined layout path can be straight, C-shaped, O-shaped, or S-shaped.

13. A detector, characterized in that, The detector includes multiple detection modules, at least one of which is the detection module according to any one of claims 1-12.

14. The detector according to claim 13, characterized in that, The plurality of detection modules include a primary detection module and a secondary detection module arranged adjacent to each other, wherein the primary detection module is the detection module according to any one of claims 1-12. The first reflective layer between the sides of adjacent scintillation crystals of the primary detection module and the secondary detection module includes a light-transmitting window. The light-transmitting window is configured to allow visible light photons in any scintillation crystal of the secondary detection module to be conducted to the optical path of the primary detection module and detected by at least two optical sensors in the primary detection module.

15. The detector according to claim 14, characterized in that, The primary detection module includes a first primary detection module and a second primary detection module, which are respectively adjacent to the secondary detection module. The light-transmitting window includes a light-transmitting window between the sides of adjacent scintillation crystals between the first-level detection module and the second-level detection module, and a light-transmitting window between the sides of adjacent scintillation crystals between the second-level detection module and the second-level detection module. The at least two optical sensors include the optical sensors in the first-level detection module and / or the second-level detection module.

16. The detector according to claim 15, characterized in that, There are multiple secondary detection modules, arranged between the first-level detection module and the second-level detection module. The first reflective layer between the sides of adjacent scintillation crystals between any two secondary detection modules includes a light-transmitting window, which is configured to allow visible light photons in any scintillation crystal within any secondary detection module to be transmitted to the adjacent secondary detection module.

17. The detector according to claim 14, characterized in that, A light-transmitting window is provided between adjacent scintillation crystals in the secondary detection module.

18. A transmission imaging device, characterized in that, include: The detector according to any one of claims 13-17; as well as A processor module, which is electrically connected to the photoelectric sensor of the detector, is used to decode events.

19. The emission imaging device according to claim 18, characterized in that, The processor module is specifically used for: Based on the photon intensity received by multiple photoelectric sensors in the same detection module and the photon transmittance of the light transmission window, the number of light transmission windows that visible light photons pass through to reach the multiple photoelectric sensors is determined, and then the location of the scintillation crystal in the detection module is decoded. and / or Based on the photon intensity received by multiple photoelectric sensors in the same detection module and the length of a single scintillation crystal, the total length of the scintillation crystal through which visible light photons pass to reach the multiple photoelectric sensors is determined, thereby decoding the reaction depth where the event occurs within the scintillation crystal.

20. A method for decoding the detection module according to any one of claims 1-12, characterized in that, The method includes: Based on the intensity of at least two received photons from the plurality of photoelectric sensors and the phototransmittance of the light-transmitting window, the location of the scintillation crystal where the decoding event occurred; and / or Based on the intensity of at least two of the photons received by the plurality of photoelectric sensors and the length of a single scintillation crystal, the total length of visible light photons reaching the at least two scintillation crystals through which they pass is determined, and the reaction depth in which the event occurs within the scintillation crystal is then decoded.

21. The method according to claim 20, characterized in that, The plurality of photoelectric sensors includes a first photoelectric sensor and a second photoelectric sensor, and the step in which the decoding event occurs at the reaction depth within the scintillation crystal specifically includes: Define the calculation factor for the reaction depth. h : in S1 The intensity of the photons received by the first photoelectric sensor. S2 The intensity of the photons received by the second photoelectric sensor; and based on S 1+ S 2 and S 1 max + S 2 max The ratio or h The absolute value of is used to calculate the reaction depth in which the event occurs within the scintillation crystal, where S 1 max and S 2 max These are the maximum detection values ​​of the first photoelectric sensor and the second photoelectric sensor, respectively, when the event occurs at the very middle of the optical path.

Images