Detection module and emission imaging device having the same

Abstract

This invention provides a detection module and an emission imaging device having the detection module. The detection module includes multiple detection units arranged in a horizontal plane. Each detection unit includes a scintillation crystal array, a photoconductor layer, and a photosensitive sensor arranged sequentially along a longitudinal direction perpendicular to the horizontal plane. The scintillation crystal array includes multiple scintillation crystals arranged in the horizontal plane. The receiving area of ​​the photosensitive sensor is smaller than the cross-sectional area of ​​the scintillation crystal array. The photoconductor layer has opposing first and second end faces along the longitudinal direction. The first end face is coupled to the scintillation crystal array, and the second end face is coupled to the photosensitive sensor. The area of ​​the first end face is larger than the area of ​​the second end face. By setting the photoconductor layer to a structure that is larger at the top and smaller at the bottom, this invention effectively reduces the number of photosensitive sensors required, thereby reducing the cost of the detection module, enhancing its market competitiveness, and further facilitating the widespread application of emission imaging devices.

Description

Technical Field

[0001] This invention relates to emission imaging systems, and more specifically, to a detection module for an emission imaging device and an emission imaging device including the detection module. Background Technology

[0002] Electron emission imaging devices, including positron emission tomography (PET) devices, have been used in medical diagnosis. Taking PET devices as an example, they utilize the annihilation effect of positrons produced by the decay of positron isotopes with negative electrons in the human body. By injecting compounds labeled with positron isotopes into the human body, a composite detection method is used to detect the gamma photons generated by the annihilation effect to achieve tomographic imaging.

[0003] The detection system is generally assembled from multiple detection modules. Each module includes a coupled scintillation crystal and a photodetector. High-energy photons (γ photons) of 511 keV generated by the annihilation effect react within the scintillation crystal and are converted into a visible photon cluster. This visible photon cluster can exit from the bottom surface of the scintillation crystal and be captured by the photodetector. By analyzing the magnitude of the visible light signal acquired by the photodetector and using the Anger Logic algorithm, the system can calculate which scintillation crystal array the γ photon reacted within. This process is called crystal decoding. In this way, information on the distribution of isotopes within the human body can be obtained. A computer then performs reconstruction and combination calculations to obtain a three-dimensional tomographic image of the distribution of labeled compounds within the human body.

[0004] Emission imaging equipment plays a significant role in the early diagnosis and treatment planning of various diseases. However, the high cost of these devices currently results in exorbitant examination fees for patients, which severely hinders their widespread adoption. Therefore, reducing the cost of emission imaging equipment in various aspects is an urgent problem to be solved. 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 for an emission imaging device is provided. The detection module includes a plurality of detection units arranged in a transverse plane, each of the plurality of detection units including a scintillation crystal array, a light guide layer, and a light sensor arranged sequentially along a longitudinal direction perpendicular to the transverse plane, wherein the scintillation crystal array includes a plurality of scintillation crystals arranged in the transverse plane; the receiving area of ​​the light sensor is smaller than the cross-sectional area of ​​the scintillation crystal array; the light guide layer has opposing first end faces and second end faces along the longitudinal direction, the first end face being coupled to the scintillation crystal array, and the second end face being coupled to the light sensor; and the area of ​​the first end face is larger than the area of ​​the second end face.

[0006] For example, the transverse plane has a first transverse direction and a second transverse direction that are perpendicular to each other. A first light-reflecting layer is disposed between adjacent detection units along the first transverse direction. A first light-transmitting window is disposed on the first light-reflecting layer to allow light to pass through the first light-transmitting window to reach the light sensor coupled to the scintillation crystal array adjacent along the first transverse direction.

[0007] For example, the light guide layer further has a side surface connected between the first end face and the second end face, wherein along the first lateral direction, the size of the first end face is larger than the size of the second end face to form a first contour boundary line between the side surfaces of the light guide layers of adjacent detection units along the first lateral direction, the first contour boundary line being lower than the second end face when viewed along a direction from the second end face to the first end face; and the first light reflective layer extends from the front of the scintillation crystal array to the first contour boundary line.

[0008] For example, along the first lateral direction, the ratio of the number of scintillation crystals to the number of optical sensors is 2:1.

[0009] For example, along the second lateral direction, the ratio of the number of scintillation crystals to the number of optical sensors is n:1, where n is greater than or equal to 1.

[0010] For example, n is 1 or 1.5.

[0011] For example, a second light-reflecting layer is disposed between adjacent detection units along the second lateral direction.

[0012] For example, in a cross section parallel to the second transverse direction and the longitudinal direction, the light-guiding layer has a uniform size along the longitudinal direction, and the second light-reflecting layer extends from the front of the scintillation crystal array toward the light sensor and is spaced apart from the light sensor.

[0013] For example, the light guide layer further has a side surface connected between the first end face and the second end face, wherein the size of the first end face is larger than the size of the second end face along the second lateral direction to form a second contour boundary line between the side surfaces of the light guide layers of adjacent detection units along the second lateral direction, the second contour boundary line being lower than the second end face when viewed along a direction from the second end face to the first end face; and the second light reflective layer extends from the front of the scintillation crystal array to the second contour boundary line.

[0014] For example, a second light-transmitting window is provided on the second light-reflecting layer to allow light to pass through the second light-transmitting window to reach the light sensor coupled to the scintillation crystal array adjacent along the second lateral direction.

[0015] For example, along the second lateral direction, the ratio of the number of scintillation crystals to the number of optical sensors is 2:1.

[0016] For example, the light guide layer is in the shape of a regular square frustum.

[0017] For example, the second light-transmitting window includes one or more of the following: a lower window adjacent to the back side of the scintillation crystal array, an upper window adjacent to the front side of the scintillation crystal array, a plurality of discrete windows evenly distributed, and side windows disposed on both sides of the first light-reflecting layer.

[0018] For example, at the second light-transmitting window, adjacent detection units are coupled by optical adhesive.

[0019] For example, the first light-transmitting window includes one or more of the following: a lower window adjacent to the back side of the scintillation crystal array, an upper window adjacent to the front side of the scintillation crystal array, a plurality of discrete windows evenly distributed, and side windows disposed on both sides of the first light-reflecting layer.

[0020] For example, at the first light-transmitting window, adjacent detection units are coupled by optical adhesive.

[0021] For example, the gaps between the light guide layers of adjacent detection units are filled with reflective material.

[0022] For example, a third light-reflecting layer is provided on the front side of the scintillation crystal array and between adjacent scintillation crystals within the scintillation crystal array.

[0023] According to another aspect of the present invention, an emission imaging device is also provided. The emission imaging device includes any of the detection modules described above.

[0024] This invention, by configuring the photoconductor layer with a larger top and smaller bottom structure, allows for the selection of a photosensitive sensor with a smaller receiving area to be adapted to a scintillation crystal array with a larger cross-sectional area. A smaller receiving area means a smaller overall size of the photosensitive sensor. Therefore, the amount of photosensitive material used can be effectively reduced, thereby lowering the cost of the detection module, enhancing its market competitiveness, and facilitating the widespread application of emission imaging equipment. Furthermore, by reducing the area of ​​the second end face of the photoconductor layer, the interface area between the photoconductor layer and the photosensitive sensor can be reduced. When using coupling agents such as adhesives, this reduces the probability of uneven coupling agent formation and air bubbles at the interface.

[0025] 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.

[0026] The advantages and features of the present invention will be described in detail below with reference to the accompanying drawings. Attached Figure Description

[0027] 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,

[0028] Figure 1 A bottom view of a detection module for an emission imaging device according to a first exemplary embodiment of the present invention;

[0029] Figure 2 for Figure 1 A top view of the detection module shown;

[0030] Figure 3 For along Figure 2 The cross-sectional view obtained by cutting the detection module through the cutting line AA shown;

[0031] Figure 4 For along Figure 2 The cross-sectional view obtained by cutting the detection module through the cutting line BB shown;

[0032] Figure 5 A cross-sectional view of the detection module according to a second exemplary embodiment of the present invention along the first transverse direction;

[0033] Figure 6 for Figure 5 The detection module shown is a cross-sectional view along the second transverse direction;

[0034] Figures 7A-7B They are respectively Figure 5 The side and bottom views of the optical guide layer of the detection module are shown.

[0035] Figure 8A A cross-sectional view of a scintillation crystal array according to an exemplary embodiment of the present invention;

[0036] Figure 8B for Figure 8A A schematic diagram of the first light-reflecting layer is shown;

[0037] Figure 9A A cross-sectional view of a scintillation crystal array according to another exemplary embodiment of the present invention;

[0038] Figure 9B for Figure 9A A schematic diagram of the first light-reflecting layer is shown;

[0039] Figure 10A A cross-sectional view of a scintillation crystal array according to yet another exemplary embodiment of the present invention;

[0040] Figure 10B for Figure 10A A schematic diagram of the first light-reflecting layer is shown;

[0041] Figure 11A A cross-sectional view of a scintillation crystal array according to another exemplary embodiment of the present invention;

[0042] Figure 11B for Figure 11A A schematic diagram of the first light-reflecting layer is shown;

[0043] Figure 12A A cross-sectional view of a scintillation crystal array according to yet another exemplary embodiment of the present invention;

[0044] Figure 12B for Figure 12A A schematic diagram of the first light-reflecting layer is shown;

[0045] Figure 13 A bottom view of the detection module according to a third exemplary embodiment of the present invention;

[0046] Figure 14 for Figure 13 The detection module shown is a cross-sectional view along the first transverse direction;

[0047] Figure 15 for Figure 13 The detection module shown is a cross-sectional view along the second transverse direction;

[0048] Figure 16 A bottom view of the detection module according to a fourth exemplary embodiment of the present invention;

[0049] Figure 17 A bottom view of the detection module according to a fifth exemplary embodiment of the present invention;

[0050] Figure 18 A bottom view of the detection module according to a sixth exemplary embodiment of the present invention; and

[0051] Figure 19 This is a bottom view of the detection module according to a seventh exemplary embodiment of the present invention. Detailed Implementation

[0052] 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 pertains only to preferred embodiments of the invention, and that the invention can be practiced without one or more of these details. Furthermore, to avoid confusion with the invention, some technical features well-known in the art have not been described.

[0053] Currently, optical sensors used in emission imaging equipment typically include the following types: photomultiplier tubes (PMTs), position-sensitive photomultiplier tubes (PS-PMTs), and silicon photomultiplier tubes (SiPMs). Regardless of the optical sensor chosen, the size of the scintillation crystal array in current emission imaging equipment is generally comparable to the size of the optical sensor, and the two can be directly coupled or coupled through a photoconductive layer. The scintillation crystal array is located at the front end of the optical sensor, close to the subject being detected. The scintillation crystal array can be arranged in a cylindrical shape to allow the subject to enter the cylinder for imaging. Therefore, the number of optical sensors used is extremely large. Among the various types of optical sensors, SiPMs are favored due to their high gain, low-voltage operation, excellent timing performance, high sensitivity (down to a single photon), and high resistance to magnetic fields. However, SiPMs are relatively expensive, and their large-scale use significantly impacts the overall cost of emission imaging equipment.

[0054] Furthermore, whether the scintillation crystal array is directly coupled to the photosensitive sensor or coupled with a photoconductive layer between the two, a coupling agent needs to be formed at the interface. Commonly used coupling agents include optical adhesives and thin-layer barium sulfate. During the coupling agent formation process at the interface, phenomena such as uneven coupling agent formation and the introduction of air bubbles into the coupling agent may occur. These will affect the optical performance of the detection module, leading to problems such as inaccurate or even uncontrollable transmittance control, as well as uneven distribution of decoding spots. Moreover, the larger the interface area, the greater the possibility of these phenomena occurring during the coupling agent formation process.

[0055] According to one aspect of the present invention, a detection module (hereinafter referred to as the detection module) for a transmission imaging device is provided. Figure 1-3 A detection module according to an embodiment of the present invention is shown from various angles. Figure 1-3For clarity and convenience, a transverse plane of the detection module is defined. This transverse plane contains a first transverse direction (X direction as shown in the figure) and a second transverse direction (Y direction as shown in the figure). The first transverse direction X and the second transverse direction Y can be perpendicular to each other. Furthermore, a direction perpendicular to the transverse plane is defined as the longitudinal direction (Z direction as shown in the figure). The longitudinal direction Z is perpendicular to both the first transverse direction X and the second transverse direction Y. For a single detection module, the transverse plane may be generally planar; however, for the entire emission imaging device, especially a cylindrical emission imaging device, the transverse plane may be generally cylindrical.

[0056] The detection module may include multiple detection units 100 arranged in a transverse plane. The multiple detection units 100 may be arranged in a p×q array along a first transverse direction X and a second transverse direction Y, where p and q are both positive integers. (See attached diagram.) Figure 13 , 16 The embodiment of the multiple detection modules shown in -19 includes, but is not limited to, 2×2, 3×6, 3×3, 6×1, 5×4, etc. (See also: [link to previous section]) Figure 1-3 It should be noted that, to explain the detection unit 100 as clearly as possible, a rectangle 110 drawn with a dashed line surrounds the detection unit 100 to distinguish it from adjacent detection units. Each rectangle 110 surrounds one detection unit 100. Figure 1-2 In the original design, all detection units 100 are divided by rectangular frames 110, and adjacent detection units 100 are spaced apart. However, in actual emission imaging equipment, the detection units 100 are not surrounded by these rectangular frames 110, and adjacent detection units 100 can be placed close together, just like... Figure 3 As shown.

[0057] Each detection unit 100 may include a scintillation crystal array 200, a photoconductor layer 300, and a photosensor 400. The scintillation crystal array 200, the photoconductor layer 300, and the photosensor 400 may be arranged sequentially along the longitudinal direction Z, such as... Figure 3 As shown, the photoconductor layer 300 is coupled between the scintillation crystal array 200 and the photosensor 400.

[0058] The scintillation crystal array 200 may include a plurality of scintillation crystals 210 arranged in a transverse plane. The scintillation crystals 210 may be elongated strips extending along the longitudinal direction Z. The size of the scintillation crystals 210 may be between 3 and 4 millimeters along the first transverse direction X and the second transverse direction Y. These scintillation crystals 210 may be arranged in an array along the first transverse direction X and the second transverse direction Y. (See attached diagram.) Figure 13 , 16In the embodiment of the multiple detection modules shown in -19, the scintillation crystal array 200 can be, but is not limited to, scintillation crystals of 2×2, 2×1, 2×3, 4×4, 4×5, 4×2, etc. A light-reflecting layer can be disposed between adjacent scintillation crystals 210. The scintillation crystal 210 can be one or more of the following: active sodium thallium iodide crystal, bismuth germanate crystal, lutetium silicate crystal, and lutetium-yttrium silicate crystal.

[0059] The receiving area of ​​the optical sensor 400 can be smaller than the cross-sectional area of ​​the scintillation crystal array 200. The receiving area of ​​the optical sensor 400 refers to the area of ​​its photosensitive surface. The larger the receiving area of ​​the optical sensor 400, the larger its overall size. The cross-sectional area of ​​the scintillation crystal array 200 is the area of ​​the cross section formed by cutting the scintillation crystal array 200 along a transverse plane. As mentioned earlier, the optical sensor 400 can be one or more of the following: a photomultiplier tube (PMT), a position-sensitive photomultiplier tube (PS-PMT), and a silicon photomultiplier tube (SiPM).

[0060] See Figure 3 The photoconductor layer 300 may have a first end face 310 and a second end face 320. The first end face 310 and the second end face 320 may be disposed opposite each other along the longitudinal direction Z. The first end face 310 may be the upper end face of the photoconductor layer 300 as shown in the figure, and the second end face 320 may be the lower end face of the photoconductor layer 300 as shown in the figure. The first end face 310 may be coupled to the scintillation crystal array 200 by any suitable means, such as an optical adhesive or air coupling. The second end face 320 may be coupled to the photosensor 400 by any suitable means, such as an optical adhesive or air coupling.

[0061] The area of ​​the first end face 310 can be larger than the area of ​​the second end face 320. Along the direction from the first end face 310 to the second end face 320 (i.e., from top to bottom), the light guide layer 300 can have a reduced size. Exemplarily, the reduction in area from the first end face 310 to the second end face 320 can be achieved by means of a bevel, making the light guide layer 300 generally wedge-shaped. Exemplarily, as... Figure 5-6 As shown, the optical guide layer 300' can be directly reduced from the first end face 310' to the second end face 320'; or as... Figure 3As shown, the photoconductor layer 300 can shrink starting from a position between the first end face 310 and the second end face 320 (i.e., a position at a distance h from the first end face 310), where the size of h can be arbitrary. Exemplarily, the reduction in area from the first end face 310 to the second end face 320 can also be achieved through a curved surface. For example, the photoconductor layer 300 can also have a side surface 330 connecting the first end face 310 and the second end face 320, which can be an arc-shaped surface. The area of ​​the first end face 310 can be comparable to the cross-sectional area of ​​the scintillation crystal array 200. The area of ​​the second end face 320 can be comparable to the receiving area of ​​the photosensor 400.

[0062] This invention, by configuring the photoconductor layer 300 with a structure that is larger at the top and smaller at the bottom, allows for the selection of a photosensitive sensor 400 with a smaller receiving area to accommodate a scintillation crystal array 200 with a larger cross-sectional area. The smaller receiving area of ​​the photosensitive sensor 400 means a smaller overall size. Therefore, the amount of photosensitive sensor 400 used can be effectively reduced, thereby lowering the cost of the detection module, enhancing its market competitiveness, and facilitating the widespread application of emission imaging equipment. Furthermore, by reducing the area of ​​the second end face 320 of the photoconductor layer 300, the interface area between the photoconductor layer 300 and the photosensitive sensor 400 can be reduced. When using coupling agents such as adhesives, this reduces the probability of uneven coupling agent formation and air bubbles at the interface.

[0063] Preferably, such as Figure 3 As shown, the detection module may further include a first light-reflecting layer 510. The first light-reflecting layer 510 may be located between adjacent detection units 100 along the first lateral direction X.

[0064] The first light-reflecting layer 510 can be formed, for example, by coating, plating (e.g., spraying or silvering), or attaching a reflective material. Reflective materials include, for example, ESR (Enhanced Specular Reflector) reflective sheets, Teflon reflective material manufactured by DuPont, or barium sulfate. The first light-reflecting layer 510 can optically isolate the scintillation crystals 210 belonging to adjacent detection units 100 and adjacent to each other. The first light-reflecting layer 510 can also extend into the light guide layer 300. In actual fabrication, the portion of the first light-reflecting layer 510 located between adjacent scintillation crystals 210 and the portion of the first light-reflecting layer 510 located within the light guide layer 300 can be fabricated separately. When the light guide layer 300 is coupled to the scintillation crystal array 200, these two portions of the first light-reflecting layer 510 are aligned. For example, the portion of the first light-reflecting layer 510 located between adjacent scintillation crystals 210 may be formed of ESR, and the portion of the first light-reflecting layer 510 located within the light-conducting layer 300 may be formed of barium sulfate. Of course, these two portions may also be formed of the same material or integrally formed.

[0065] Continue to refer to Figure 3A first light-transmitting window 610 may be provided on the first light-reflecting layer 510. In this way, light from the scintillation crystal array 200 can pass through the first light-transmitting window 610 to reach the photosensitive sensor 400 coupled to the adjacent scintillation crystal array 200. Specifically, in the illustrated embodiment, the left scintillation crystal array 200 may include a first scintillation crystal 211 and a second scintillation crystal 212, and the right scintillation crystal array 200 may include a third scintillation crystal 213 and a fourth scintillation crystal 214. The photosensitive sensor 400 coupled to the left scintillation crystal array 200 is called the first photosensitive sensor 410, and the photosensitive sensor 400 coupled to the right scintillation crystal array 200 is called the second photosensitive sensor 420. Thus, when high-energy photons (e.g., 511 keV gamma photons) interact in the second scintillation crystal 212, the resulting low-energy photon group (e.g., a 420 nm photon group) can enter the adjacent third scintillation crystal 213 through the first light-transmitting window 610 and be received by the second photosensitive sensor 420 coupled to the right scintillation crystal array 200. The low-energy photon cluster generated within the first scintillation crystal 211 can almost only be received by the first optical sensor 410. Therefore, by analyzing the light distribution detected by the first optical sensor 410 and the second optical sensor 420, it can be calculated whether the high-energy photon reaction occurred in the first scintillation crystal 211 or the second scintillation crystal 212, thus completing crystal position decoding. Similarly, for high-energy photons reacting in the third scintillation crystal 213 and the fourth scintillation crystal 214, crystal position decoding can also be performed using the light distribution detected by the first optical sensor 410 and the second optical sensor 420. In the first transverse direction X, the ratio of scintillation crystals 210 to optical sensors 400 can be 2:1. This allows for convenient position decoding of each adjacent scintillation crystal in the first transverse direction X within each detection unit. Of course, if feasible, the ratio of scintillation crystals 210 to optical sensors 400 can also have other values. Meanwhile, due to the presence of the first light-transmitting window 610, the amount of light passing through the first light-transmitting window 610 and reaching the adjacent photosensitive sensor 400 will differ when the distance from the reaction position to the first light-transmitting window 610 changes. Therefore, for reactions occurring in the second scintillation crystal 212 and the third scintillation crystal 213, depth of reaction (DOI) decoding can still be performed. However, DOI decoding may not be possible for the first scintillation crystal 211 and the fourth scintillation crystal 214.

[0066] At the first light-transmitting window 610, adjacent detection units 100 can be coupled via optical adhesive, air coupling, or a thin layer of barium sulfate. Air coupling offers good uniformity, but the significant difference in refractive index between air and the scintillation crystal results in a large total internal reflection angle when photons pass through the first light-transmitting window 610, thus reducing transmittance. Optical adhesive, on the other hand, has a smaller difference in refractive index between the optical adhesive and the scintillation crystal, resulting in better transmittance. However, due to the adhesive's viscosity and the small spacing between adjacent scintillation crystals, uneven filling and air bubbles can easily occur when filling the first light-transmitting window 610, potentially leading to performance inconsistencies. A thin layer of barium sulfate (e.g., approximately 0.2 mm) can achieve 15% transmittance, but the transmittance of barium sulfate is closely related to its thickness, requiring strict control over its thickness when filling the first light-transmitting window 610. Those skilled in the art can choose the coupling method of the detection unit 100 at the first light-transmitting window 610 according to their needs. The inventors found that, in practice, optical adhesive coupling is more practical among the three methods described above.

[0067] In addition, the first light-transmitting window 610 can be positioned in various ways. Several preferred embodiments of the first light-transmitting window 610 are described below.

[0068] Optionally, such as Figures 8A-8B As shown, the first light-transmitting window may include a lower window 611. The lower window 611 may be adjacent to the back side of the scintillation crystal array 200. The front side of the scintillation crystal array 200 refers to the side that receives high-energy photons, while the back side is positioned opposite the front side along the longitudinal direction Z.

[0069] Optionally, such as Figures 9A-9B As shown, the first light-transmitting window may include an upper window 612. The upper window 612 may be adjacent to the front side of the scintillation crystal array 200.

[0070] Optionally, such as Figures 10A-10B As shown, the first light-transmitting window may include a lower window 611 and an upper window 612.

[0071] Optionally, such as Figure 11A-11B As shown, the first light-transmitting window may include multiple discrete windows 613. The multiple discrete windows 613 may be evenly distributed. The method of even distribution is not limited.

[0072] Optionally, such as Figure 12A-12B As shown, the first light-transmitting window may include side windows 614 and 615. Side windows 614 and 615 may be disposed on both sides of the first light-reflecting layer 510. Side windows 614 and 615 may be the same or different.

[0073] See back Figure 3Along the first lateral direction X, the size of the first end face 310 can be larger than the size of the second end face 320. Thus, when viewed from the second end face 320 towards the first end face 310 (i.e., from bottom to top), a first contour boundary line 340 is formed between the side surfaces 330 of the photoconductor layers 300 of adjacent detection units 100 along the first lateral direction X. The first contour boundary line 340 is lower than the second end face 320. Consequently, when viewed from bottom to top, a gap 350 is formed between the side surfaces 330 of the photoconductor layers 300 of adjacent detection units 100 along the first lateral direction X. This gap 350 is filled with a reflective material. This allows photon groups in the photoconductor layer 300 to be guided into the corresponding photosensor 400.

[0074] The first light-reflecting layer 510 can extend from the front of the scintillation crystal array 200 to the first contour boundary line 340. Figure 1-4 In the first embodiment shown, the first contour boundary line 340 is located between the first end face 310 and the second end face 320 along the longitudinal direction Z, and the first light reflective layer 510 extends from the scintillation crystal array 200 into the light guide layer 300. Figure 5-6 In the second embodiment shown, the first contour boundary line 340' is located within the first end face 310'. In this case, the first light-reflecting layer 510' essentially only optically isolates the adjacent scintillation crystal 210', and the longitudinal dimension of the first light-reflecting layer 510' is essentially equal to the longitudinal dimension of the scintillation crystal 210'. A first light-transmitting window 610' can still be formed in the first light-reflecting layer 510'. The first light-transmitting window 610' can be substantially the same as the aforementioned first light-transmitting window 610. In the second embodiment, since the first contour boundary line 340' is located within the first end face 310', the first light-reflecting layer 510' does not need to extend into the light guide layer 300'. Therefore, the first light-reflecting layer 510' can be formed during the fabrication of the scintillation crystal array 200', simplifying the manufacturing process. Furthermore, relative to... Figure 3-4 The first light-reflecting layer 510 shown extends into the light-conducting layer 300, and the first light-reflecting layer 510, in the case of the separate manufacturing embodiment, has lower requirements for alignment accuracy, thereby improving yield and reducing processing costs.

[0075] See back Figure 4A second light-reflecting layer 520 can be disposed between adjacent detection units 100 along the second lateral direction Y. The material and formation method of the second light-reflecting layer 520 can be similar to those of the first light-reflecting layer 510 described above. The second light-reflecting layer 520 can optically isolate the scintillation crystals belonging to adjacent detection units 100 and adjacent to each other. The second light-reflecting layer 520 can also extend into the light guide layer 300. In actual fabrication, the portion of the second light-reflecting layer 520 located between adjacent scintillation crystals and the portion of the second light-reflecting layer 520 located within the light guide layer 300 can be fabricated separately. When the light guide layer 300 is coupled to the scintillation crystal array 200, these two portions of the second light-reflecting layer 520 can be aligned.

[0076] A second light-transmitting window 620 may be provided on the second light-reflecting layer 520 to allow light to pass through the second light-transmitting window 620 to reach the photosensor 400 coupled to the adjacent scintillation crystal array 200 along the second lateral direction Y. Specifically, in the illustrated embodiment, the scintillation crystal array 200 on the left may include a first scintillation crystal 211 and a fifth scintillation crystal 215, and the scintillation crystal array 200 on the right may include a sixth scintillation crystal 216 and a seventh scintillation crystal 217. The photosensor 400 coupled to the left scintillation crystal array 200 is a first photosensor 410, and the photosensor 400 coupled to the right scintillation crystal array 200 is a third photosensor 430. In this way, when high-energy photons react in the fifth scintillation crystal 215, the resulting low-energy photon group can enter the adjacent sixth scintillation crystal 216 through the second light-transmitting window 620, and then be received by the third photosensor 430 coupled to the right scintillation crystal array 200. As described above, the low-energy photon group generated in the reaction in the first scintillation crystal 211 can almost only be received by the first photosensor 410. Therefore, by analyzing the light distribution detected by the first optical sensor 410 and the third optical sensor 430, it can be calculated whether the high-energy photon reacted in the first scintillation crystal 211 or the fifth scintillation crystal 215, thus completing crystal position decoding. Similarly, for high-energy photons reacting in the sixth scintillation crystal 216 and the seventh scintillation crystal 217, crystal position decoding can also be completed by analyzing the light distribution detected by the first optical sensor 410 and the third optical sensor 430. In the second transverse direction Y, the ratio of scintillation crystals 210 to optical sensors 400 can be 2:1. This allows for convenient position decoding of each adjacent scintillation crystal in the second transverse direction Y within each detection unit. Of course, if feasible, the ratio of scintillation crystals 210 to optical sensors 400 can also have other values. The fifth scintillation crystal 215 and the sixth scintillation crystal 216 can be used for DOI decoding, while the first scintillation crystal 211 and the seventh scintillation crystal 217 may not be able to be used for DOI decoding.

[0077] Similar to the first light-transmitting window 610, the second light-transmitting window 620 may include a lower window adjacent to the back surface of the scintillation crystal array 200 (see [link to documentation]). Figures 8A-8B ), the upper window adjacent to the front of the scintillation crystal array 200 (see Figures 9A-9B ), top window and bottom window (see Figures 10A-10B ), multiple discrete windows that are uniformly distributed (see Figure 11A-11B ), and side windows located on both sides of the second light-reflecting layer (see Figure 12A-12B One or more of the following.

[0078] At the second light-transmitting window 620, adjacent detection units 100 can be coupled via optical adhesive, air coupling, or a thin layer of barium sulfate. Preferably, they are coupled via optical adhesive.

[0079] Along the second transverse direction Y, the size of the first end face 310 can be larger than the size of the second end face 320. Thus, when viewed from the second end face 320 towards the first end face 310 (i.e., from bottom to top), a second contour boundary line 360 ​​is formed between the side surfaces 330 of the light guide layers 300 of adjacent detection units 100 along the second transverse direction Y. The second contour boundary line 360 ​​is lower than the second end face 320. Consequently, when viewed from bottom to top, a gap 350 is formed between the side surfaces 330 of the light guide layers 300 of adjacent detection units 100 along the second transverse direction Y. Reflective material is filled within this gap 350. This allows photon groups in the light guide layer 300 to be guided into the corresponding photosensor 400. The second light reflective layer 520 extends from the front of the scintillation crystal array 200 to the second contour boundary line 360. By providing a second light-transmitting window 620 on the second light reflective layer 520, crystal position decoding can be completed.

[0080] When the photoconductor layer 300 has a reduced size along the first lateral direction X and the second lateral direction Y, the amount of photoconductor 400 used can be significantly reduced. When the size of the photoconductor 400 is comparable to that of a single scintillator crystal 210, the amount of photoconductor 400 used can be reduced by 75%.

[0081] Preferably, the light guide layer 300 can be in the shape of a regular square frustum, such as... Figures 7A-7B As shown, this reduces the difficulty of manufacturing and thus the cost of the emission imaging equipment.

[0082] A third light-reflecting layer 530 may be disposed on the front side of the scintillation crystal array 200 and between adjacent scintillation crystals 210 within the scintillation crystal array 200. (See also...) Figure 3-4The material and formation of the third light-reflecting layer 530 can be similar to those of the first light-reflecting layer 510 described above. This prevents photon groups from escaping outside the scintillation crystal array 200.

[0083] exist Figure 13-15 In the third exemplary embodiment shown, the first light-transmitting window 610” can be provided only in the first lateral direction X, while no light-transmitting window is provided in the second lateral direction Y. In the first lateral direction X, the ratio of the number of scintillation crystals 210” to the number of light sensors 400” is 2:1. The crystal position decoding in the first lateral direction X has been described in detail above and will not be described in detail here for the sake of brevity. In the second lateral direction Y, in order to realize crystal position decoding, on a cross section parallel to the second lateral direction Y and the longitudinal direction Z, as shown... Figure 15 As shown, the light-conducting layer 300” has a uniform size along the longitudinal direction Z, and the second light-reflecting layer 520” extends from the front side of the scintillation crystal array 200” toward the light sensor 400” and is spaced apart from the light sensor 400”. Exemplarily, the second light-reflecting layer 520” can extend from the front side of the scintillation crystal array 200” to its back side. In this case, along the second transverse direction Y, the ratio of the number of scintillation crystals 210” to the number of light sensors 400” can be n:1, where n is greater than or equal to 1. Figure 13-15 In the illustrated embodiment, n = 1.5. Three scintillation crystals can couple two optical sensors. Specifically, as... Figure 15 As shown, scintillation crystals 221, 225, and 226 are coupled to photosensitive sensors 450 and 460. Scintillation crystals 227, 228, and 229 are coupled to photosensitive sensors 470 and 480. Most of the low-energy photon clusters generated within scintillation crystal 221 can be detected by photosensitive sensor 450, while a small portion is detected by photosensitive sensor 460. The low-energy photon clusters generated within scintillation crystal 225 are detected substantially equally by photosensitive sensors 450 and 460. Most of the low-energy photon clusters generated within scintillation crystal 226 can be detected by photosensitive sensor 460, while a small portion is detected by photosensitive sensor 450. Based on the amount of light detected by photosensitive sensors 450 and 460, crystal position decoding can be performed on scintillation crystals 221, 225, and 226. The same applies to scintillation crystals 227, 228, and 229.

[0084] Of course, optionally, n can be equal to 1, such as Figure 16 As shown, each optical sensor 400 can be coupled to a scintillation crystal 210 along the second lateral direction Y. Those skilled in the art will understand the crystal position decoding along the second lateral direction Y based on the above description.

[0085] Optionally, such as Figure 17 As shown, n can be equal to 4 / 3. (e.g.) Figure 18As shown, n can be equal to 5 / 3. (For example...) Figure 19 As shown, n can be equal to 2.

[0086] The above only describes the differences between the different embodiments. The same reference numerals are used for the same or similar parts in the different embodiments, and for the sake of brevity, these same or similar parts will not be described in detail here.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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 for a transmission imaging device, characterized in that, The system includes multiple detection units arranged in a transverse plane. Each of the multiple detection units includes a scintillation crystal array, a photoconductor layer, and a photosensor arranged sequentially along a longitudinal direction perpendicular to the transverse plane. The scintillation crystal array includes a plurality of scintillation crystals arranged in the transverse plane; The receiving area of ​​the optical sensor is smaller than the cross-sectional area of ​​the scintillation crystal array; The photoconductive layer has a first end face and a second end face opposite each other along the longitudinal direction. The first end face is coupled to the scintillation crystal array, and the second end face is coupled to the photosensor. The area of ​​the first end face is larger than the area of ​​the second end face. Within the transverse plane, there are a first transverse direction and a second transverse direction that are perpendicular to each other, wherein: Along the first lateral direction, each of the plurality of detection units includes a light sensor and two scintillation crystals, the two scintillation crystals including a first scintillation crystal and a second scintillation crystal; Along the first lateral direction and the second lateral direction, the size of the optical sensor is comparable to the size of a single scintillation crystal; Along the first lateral direction, the two scintillation crystals correspond to the one photosensitive sensor, such that the photosensitive sensors of adjacent detection units along the first lateral direction are spaced apart, and such that the one photosensitive sensor can receive photons from the two scintillation crystals; along the second lateral direction, the ratio of the number of scintillation crystals to the number of photosensitive sensors is n:1, where n is greater than or equal to 1; and A first light-reflecting layer is disposed between adjacent detection units along the first lateral direction. A first light-transmitting window is disposed on the first light-reflecting layer to allow photons to pass through the first light-transmitting window to reach the photosensor coupled to the adjacent scintillation crystal array along the first lateral direction. The second scintillation crystal is adjacent to the first light-transmitting window, wherein: The low-energy photon group generated by the interaction of high-energy photons in the second scintillation crystal enters the adjacent scintillation crystal array through the first light-transmitting window and is received by the optical sensor coupled to the adjacent scintillation crystal array; The low-energy photon group generated by the interaction of high-energy photons in the first scintillation crystal can be detected by almost only one optical sensor. Crystal position decoding is performed using the light distribution detected by the light sensor coupled to the adjacent scintillation crystal array.

2. The detection module as described in claim 1, characterized in that, The optical guide layer also has a side surface connected between the first end face and the second end face, wherein Along the first lateral direction, the size of the first end face is larger than the size of the second end face, so as to form a first contour boundary line between the sides of the photoconductor layers of adjacent detection units along the first lateral direction. This first contour boundary line is lower than the second end face when viewed along a direction from the second end face to the first end face. The first light-reflecting layer extends from the front of the scintillation crystal array to the first contour boundary line.

3. The detection module as described in claim 1, characterized in that, The value of n is 1 or 1.

5.

4. The detection module as described in claim 1, characterized in that, A second light-reflecting layer is disposed between adjacent detection units along the second lateral direction.

5. The detection module as described in claim 4, characterized in that, In a cross section parallel to the second transverse direction and the longitudinal direction, the light-guiding layer has a uniform size along the longitudinal direction, and the second light-reflecting layer extends from the front of the scintillation crystal array toward the light sensor and is spaced apart from the light sensor.

6. The detection module as described in claim 4, characterized in that, The optical guide layer also has a side surface connected between the first end face and the second end face, wherein Along the second lateral direction, the size of the first end face is larger than the size of the second end face, so as to form a second contour boundary line between the sides of the photoconductor layers of adjacent detection units along the second lateral direction. This second contour boundary line is lower than the second end face when viewed along a direction from the second end face to the first end face. The second light-reflecting layer extends from the front of the scintillation crystal array to the second contour boundary line.

7. The detection module as described in claim 4, characterized in that, The second light-reflecting layer is provided with a second light-transmitting window to allow light to pass through the second light-transmitting window to reach the light sensor coupled to the adjacent scintillation crystal array along the second lateral direction.

8. The detection module as described in claim 7, characterized in that, Along the second lateral direction, the ratio of the number of scintillation crystals to the number of optical sensors is 2:

1.

9. The detection module as described in claim 7, characterized in that, The light guide layer is in the shape of a regular square frustum.

10. The detection module as described in claim 7, characterized in that, The second light-transmitting window includes one or more of the following: a lower window adjacent to the back of the scintillation crystal array, an upper window adjacent to the front of the scintillation crystal array, a plurality of discrete windows evenly distributed, and side windows disposed on both sides of the first light-reflecting layer.

11. The detection module as described in claim 7, characterized in that, At the second light-transmitting window, adjacent detection units are coupled by optical adhesive.

12. The detection module as described in claim 1, characterized in that, The first light-transmitting window includes one or more of the following: a lower window adjacent to the back of the scintillation crystal array, an upper window adjacent to the front of the scintillation crystal array, a plurality of discrete windows evenly distributed, and side windows disposed on both sides of the first light-reflecting layer.

13. The detection module as described in claim 1, characterized in that, At the first light-transmitting window, adjacent detection units are coupled by optical adhesive.

14. The detection module as described in claim 1, characterized in that, The gaps between the photoconductive layers of adjacent detection units are filled with reflective material.

15. The detection module as described in claim 1, characterized in that, A third light-reflecting layer is provided on the front side of the scintillation crystal array and between adjacent scintillation crystals within the scintillation crystal array.

16. A transmissive imaging device, characterized in that, The emission imaging device includes a detection module as described in any one of claims 1-15.

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