Detector and emission imaging device

Abstract

The application provides a kind of detector and emission imaging equipment.The detector includes a plurality of scintillation crystals, a plurality of scintillation crystals form a crystal array, the crystal array has a first end and a second end, the scintillation crystal has a side surface between the first end and the second end;A plurality of first photosensors, a plurality of first photosensors form a first sensor array, the first sensor array is coupled to the first end;And a plurality of second photosensors, a plurality of second photosensors form a second sensor array, the second sensor array is coupled to the second end;Wherein, the side surface includes a first side surface between two adjacent first photosensors and a second side surface between two adjacent second photosensors, the first side surface is provided with a first light transmission window away from the first end position, and the second side surface is provided with a second light transmission window away from the second end position.The detector can use window method and double-end method simultaneously to calculate DOI with higher precision, and the spatial resolution is higher.

Description

Technical Field

[0001] This invention relates to the technical field of emission imaging equipment, and more specifically, to a detector and emission imaging equipment. 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) is a commonly used ECT technique.

[0003] Current PET technology typically employs either the window method or the two-end method to obtain Depth of Interaction (DOI). In the window method, a transparent window is placed at the end of the detector furthest from the photodetector. When a scintillation crystal detects a gamma photon, the generated visible light is transmitted to the photodetector coupled to that crystal. A portion of this visible light passes through the window to an adjacent photodetector. The further the reaction site is from the photodetector coupled to the scintillation crystal, the more visible light is detected by the adjacent photodetector. The DOI is calculated based on the ratio of visible light detected by these two photodetectors. In the two-end method, photodetectors are placed at both ends of the detector. When a scintillation crystal detects a gamma photon, the generated visible light is transmitted to two photodetectors coupled to those ends. The ratio of visible light detected by these two photodetectors varies depending on the location of the gamma photon detection on the scintillation crystal. The photodetector closer to the gamma photon detection location on the scintillation crystal detects more visible light, which is then used to calculate the DOI.

[0004] In existing designs for calculating DOI using the two-end method, the sides of the scintillation crystal need to be completely covered with a reflective layer. Conversely, in existing designs using the window method, the sides of the scintillation crystal need to have a transparent window. These two designs are contradictory. Furthermore, for the window method, when the scintillation crystal detects gamma photons near the two ends, the distance the generated visible light travels to the two photodetectors is almost equal, resulting in poor DOI accuracy calculated based on the ratio of visible light detected by the two photodetectors. Conversely, for the two-end method, when the scintillation crystal detects gamma photons at a mid-depth location, the distance the generated visible light travels to the two photodetectors is almost equal, again resulting in poor DOI accuracy calculated based on the ratio of visible light detected by the two photodetectors. 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 detector is provided. The detector includes a plurality of scintillation crystals forming a crystal array, the crystal array having a first end and a second end, and each scintillation crystal having a side surface located between the first end and the second end; a plurality of first photoelectric sensors forming a first sensor array coupled to the first end; and a plurality of second photoelectric sensors forming a second sensor array coupled to the second end; wherein the side surface includes a first side surface located between two adjacent first photoelectric sensors and a second side surface located between two adjacent second photoelectric sensors, the first side surface having a first light-transmitting window disposed at a position away from the first end, and the second side surface having a second light-transmitting window disposed at a position away from the second end.

[0006] The detector provided by this invention can simultaneously calculate the DOI information of a scintillation crystal using both the window method and the two-end method. The calculation results can be cross-referenced. Specifically, when the obtained response position is close to the central region of the scintillation crystal, the DOI information calculated using the window method has stronger reference value; conversely, when the obtained response position is close to both ends of the scintillation crystal, the DOI information calculated using the two-end method has stronger reference value. This results in higher accuracy of the final fitted result and overcomes the low accuracy problems of the window method (when the response position is close to both ends of the scintillation crystal) and the two-end method (when the response position is close to the central region of the scintillation crystal). Compared to using either the window method or the two-end method alone to calculate the DOI of the scintillation crystal, this detector can calculate the DOI information of the scintillation crystal with higher accuracy, higher spatial resolution, and better detection performance.

[0007] For example, the scintillation crystal has a size of X×Y, and the first photoelectric sensor has a size of 4X×4Y. The size ratio of the first photoelectric sensor and the scintillation crystal in the detector provided by the present invention can be 1:4, thereby allowing the use of a smaller scintillation crystal, and thus the overall device can have a smaller size for application in small animal PET detection.

[0008] For example, the second photoelectric sensor has a size of 4X×4Y. In this way, the first and second photoelectric sensors, as well as the scintillation crystal, can all have small sizes, further enabling the overall device to have a smaller size. Such a detector works better when applied to small animal PET scans.

[0009] For example, the crystal array is A1×B1 in size, and the first sensor array is A2×B2 in size, where A2 = A1 and B2 = B1, so that the crystal array is completely covered by the first sensor array at its first end. Such a detector ensures that the visible light generated by each scintillation crystal struck by a gamma photon can be detected by at least one first photoelectric sensor. This avoids situations where gamma photon strikes on the scintillation crystal go undetected, thus improving the detector's detection efficiency.

[0010] For example, the size of the second sensor array is A3×B3, where A3 < A1 and B3 < B1, so that the crystal array at the second end is divided into a central region covered by the second sensor array and a surrounding region not covered by the second sensor array. The side includes a third side located between the central region and the surrounding region, and the third side has a third light-transmitting window positioned away from the second end. When the detector needs to expand its detection range, it only needs to add some second photoelectric sensors, which can increase the number of scintillation crystals capable of calculating DOI using both the window method and the two-end method. In this case, the third light-transmitting window can function similarly to the second light-transmitting window, thereby expanding the detector's detection range.

[0011] For example, the scintillation crystal has a size of X×Y, and the crystal array has a first direction and a second direction that are perpendicular to each other. The distance between the outer edge of the peripheral region and the outer edge of the central region in the first direction is 2X, and the distance between the outer edge of the peripheral region and the outer edge of the central region in the second direction is 2Y. Such a detector is more regular, and multiple detectors can be spliced ​​together to achieve a larger detection range.

[0012] For example, the size of the second sensor array is A4×B4, where A4 > A1 and B4 > B1, so that the second sensor array has a coverage area that covers the crystal array and an extension area that extends beyond the crystal array. The design of the extension area ensures that the second sensor array completely covers the second end of the crystal array. Thus, even if the first sensor array also covers the first end of the crystal array, it can ensure that each scintillation crystal can perform DOI calculation using the two-end method, thereby improving the detector's accuracy in calculating DOI.

[0013] For example, the scintillation crystal has a size of X×Y, and the crystal array has a first direction and a second direction that are perpendicular to each other. The distance between the outer edge of the overlay area and the outer edge of the cover area in the first direction is 2X, and the distance between the outer edge of the overlay area and the outer edge of the cover area in the second direction is 2Y. Such a detector is more regular, and the multiple second photoelectric sensors have the same shape and size, resulting in a simple structure that is easy to manufacture.

[0014] For example, the size of the second sensor array is A5×B5, where A5 < A1 and B5 > B1, so that the crystal array at the second end has at least a central region covered by the second sensor array and a surrounding region not covered by the second sensor array. The side includes a third side located between the central region and the surrounding region, and the third side has a third light-transmitting window disposed at a position away from the second end. When the detector needs to expand its detection range, it only needs to add some second photoelectric sensors to enable more scintillation crystals to calculate DOI using the window method and the two-end method. In this case, the third light-transmitting window can play the same role as the second light-transmitting window, thereby expanding the detector's detection range.

[0015] For example, the scintillation crystal has a size of X×Y, and the crystal array has a first direction and a second direction that are perpendicular to each other. The distance between the outer edge of the peripheral region and the outer edge of the central region in the first direction is 2X. Furthermore, the second sensor array has an extended region in the second direction that extends beyond the crystal array, and the distance between the outer edge of the extended region and the outer edge of the central region in the second direction is 2Y. Such a detector has more scintillation crystals in the second direction, enabling the calculation of DOI using both windowing and double-ended methods, thereby improving the detector's detection performance.

[0016] For example, the first photoelectric sensor and the second photoelectric sensor are staggered. This design avoids the interference that can occur when multiple light-transmitting windows are located on the same side, which would be problematic when using the window method to calculate DOI. Therefore, this detector is easier to use for data processing and provides better detection results.

[0017] For example, the crystal array has a first direction and a second direction that are perpendicular to each other, and the first photodetector is offset from the second photodetector by two scintillation crystals in the first direction and / or the second direction. This allows the size ratio of the first photodetector and the second photodetector relative to the scintillation crystals in both the first and second directions to be 1:4. This also allows for a larger proportion of scintillation crystals in the total number of scintillation crystals when calculating the DOI using both the window method and the two-end method, resulting in better detection performance from such a detector.

[0018] According to another aspect of the present invention, a emission imaging apparatus is also provided. The emission imaging apparatus includes a processor module and any of the detectors described above, with a plurality of first photoelectric sensors and a plurality of second photoelectric sensors electrically connected to the processor module. In such an emission imaging apparatus, because the detectors can calculate the DOI with high precision, the overall device detection results have higher accuracy.

[0019] 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.

[0020] The advantages and features of the present invention will be described in detail below with reference to the accompanying drawings. Attached Figure Description

[0021] 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,

[0022] Figure 1 This is a schematic diagram of a transmission imaging device according to an exemplary embodiment of the present invention;

[0023] Figure 2 A cross-sectional view of a detector according to an exemplary embodiment of the present invention;

[0024] Figure 3 A top view of a detector according to an exemplary embodiment of the present invention;

[0025] Figure 4 for Figure 3 The detector shown is a bottom view;

[0026] Figure 5 A top view of a detector according to an exemplary embodiment of the present invention;

[0027] Figure 6 for Figure 5 The detector shown is a bottom view;

[0028] Figure 7 A top view of a detector according to an exemplary embodiment of the present invention; and

[0029] Figure 8 for Figure 7 The image shows a bottom view of the detector.

[0030] The above figures include the following reference numerals:

[0031] 10. Detector; 100. First sensor array; 110. First photoelectric sensor; 200. Second sensor array; 210. Second photoelectric sensor; 220. Exceeding area; 230. Coverage area; 300. Crystal array; 310. First end; 320. Second end; 330. Scintillation crystal; 331. First side; 332. Second side; 333. Third side; 334. First light-transmitting window; 335. Second light-transmitting window; 336. Third light-transmitting window; 337. Reflective layer; 340. Central area; 350. Surrounding area; 20. Emission imaging device; 400. Processor module; 30. Detection ring. Detailed Implementation

[0032] 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.

[0033] According to one aspect of the present invention, a detector is provided, which may include a plurality of scintillation crystals, a plurality of first photoelectric sensors, and a plurality of second photoelectric sensors, wherein the plurality of scintillation crystals can form a crystal array, the plurality of first photoelectric sensors can form a first sensor array, and the plurality of second photoelectric sensors can form a second sensor array. A scintillation crystal refers to a crystal that can convert the energy of high-energy particles into light energy under the impact of gamma photons. The scintillation crystal may 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 plurality of scintillation crystals can be closely arranged to form a crystal array, and the overall crystal array can be rectangular, circular, trapezoidal, or other shapes. The first photoelectric sensors and the second photoelectric sensors can be various existing or future types, such as photomultiplier tubes (PMTs), silicon photomultiplier tubes (SiPMs), etc. The plurality of first photoelectric sensors can be closely arranged to form a first sensor array, and the overall first sensor array can be rectangular, circular, trapezoidal, or other shapes. Multiple second photoelectric sensors can be arranged in close proximity to form a second sensor array, and the overall second sensor array can be rectangular, circular, trapezoidal, or other shapes. The first photoelectric sensor, the first sensor array, the second photoelectric sensor, and the second sensor array will be described in detail below.

[0034] According to another aspect of the present invention, a transmission imaging apparatus is provided. (See also...) Figure 1 The emission imaging device 20 may include a processor module 400 and any of the detectors 10 described below. Multiple first photoelectric sensors 110 and multiple second photoelectric sensors 210 may be electrically connected to the processor module 400. The emission imaging device 20 may include a detection ring 30. Figure 1 An enlarged view of the detector ring 30 is shown. Multiple detectors 10, as described below, can be arranged on the detector ring 30. Typically, the multiple detectors 10 forming a detector ring 30 have substantially the same structure. However, this application does not exclude embodiments where different detectors are used to form a detector ring 30. Multiple detector rings 30 can be closely arranged along a direction perpendicular to the plane of the paper. The detection space enclosed by these detector rings 30 can accommodate the object to be measured. Typically, this detection space can be substantially cylindrical. Of course, this application does not exclude embodiments where the detection space has other shapes. Multiple detectors 10 can be arranged in pairs, and the paired detectors 10 can function under PET imaging. In such an emission imaging device 20, because the detectors 10 can calculate the DOI with high precision, the overall device detection results have higher accuracy.

[0035] See Figure 2 The crystal array 300 may have a first end 310 and a second end 320. The first end 310 may be the end of the detector 10 that is closer to the organism being detected during detection, and the second end 320 may be the other end of the crystal array 300 that is farther from the organism being detected. Flipping the crystal array 300, the second end 320 may also be the end of the detector 10 that is closer to the organism being detected during detection, and the first end 310 may be the other end of the crystal array 300 that is farther from the organism being detected. It is worth noting that the first end 310 and the second end 320 here are not specific designations, but are merely used to distinguish the two ends of the crystal array 300. For ease of description, the following description will use the end of the crystal array 300 closer to the top in the ZZ direction as the first end 310, and the end of the crystal array 300 closer to the bottom in the ZZ direction as the second end 320.

[0036] The scintillation crystal 330 may have a side surface located between the first end 310 and the second end 320. The scintillation crystal 330 is typically cuboid, and thus has four side surfaces between the first end 310 and the second end 320. A reflective layer 337 may be provided on the surface of the scintillation crystal 330 that is not coupled to the first photoelectric sensor 110 or the second photoelectric sensor 210. Since the side surfaces of the scintillation crystal 330 are not coupled to the first photoelectric sensor 110 or the second photoelectric sensor 210, each side surface of the scintillation crystal 330 may be covered with a reflective layer 337 that reflects light towards the interior of the corresponding scintillation crystal 330. Providing the reflective layer 337 prevents the scintillation light generated when the scintillation crystal 330 is struck by gamma photons from affecting adjacent scintillation crystals 330. When detecting the scintillation light of a single scintillation crystal 330, the reflective layer 337 can improve the accuracy of the detection. The reflective layer 337 can be formed by spraying, coating (e.g., spraying or silvering), or bonding 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 ESR reflectors is around 40 micrometers, for example, 38 micrometers.

[0037] Multiple first photoelectric sensors 110 can form a first sensor array 100, which can be coupled to a first end 310. Multiple second photoelectric sensors 210 can form a second sensor array 200, which can be coupled to a second end 320. Coupling refers to the transmission of the flicker light signal between the first sensor array 100 and / or the second sensor array 200 and the scintillation crystal 330. The first photoelectric sensors 110 and 210 can receive the flicker light signal transmitted through the scintillation crystal 330, and then convert the flicker light signal into an electrical signal. The electrical signal can be used by a back-end processor for data processing, and after data processing, an intuitive image can be obtained. The multiple first photoelectric sensors 110 can have the same size and shape, or they can have different sizes and shapes. The multiple first photoelectric sensors 110 can be arranged closely to form the first sensor array 100, or they can be spaced apart from each other. The multiple second photoelectric sensors 210 are similar to the multiple first photoelectric sensors 110, and will not be described in detail here. A first sensor array 100 is coupled to a first end 310, and a second sensor array 200 is coupled to a second end 320. At least a portion of the scintillation crystals 330 in the crystal array 300 are simultaneously coupled to a first photoelectric sensor 110 and a second photoelectric sensor 210. When these scintillation crystals 330 are struck by gamma photons, they generate visible light. This visible light can be detected by the coupled first photoelectric sensor 110 and second photoelectric sensor 210. Based on the ratio of visible light detected by the first photoelectric sensor 110 and the second photoelectric sensor 210, the DOI information of the scintillation crystal 330 struck by gamma photons can be calculated. Therefore, such a detector 10 can implement a two-end method for calculating DOI.

[0038] Taking a scintillation crystal 330 coupled with a first photoelectric sensor 110 as an example, among adjacent scintillation crystals 330, there exists a scintillation crystal 330 coupled with another first photoelectric sensor 110. The first photoelectric sensors 110 coupled to these two scintillation crystals 330 are also adjacent to each other. The opposite sides of these two scintillation crystals 330 are called the first side surface 331. That is, the side surface can include the first side surface 331 located between two adjacent first photoelectric sensors 110. A first light-transmitting window 334 can be provided on the first side surface 331 at a position away from the first end 310. Figure 2Taking scintillation crystals 330 III and IV as examples, when scintillation crystal 330 III is struck by a gamma photon, it generates visible light. This visible light is detected by the first photoelectric sensor 110 coupled to scintillation crystal 330 III. A portion of this visible light passes through the first light-transmitting window 334 to reach scintillation crystal 330 IV, where it is also detected by the first photoelectric sensor 110 coupled to scintillation crystal 330 IV. Based on the ratio of visible light detected by these two first photoelectric sensors 110, the DOI information of scintillation crystal 330 III can be calculated. Therefore, this detector 10 can calculate the DOI using the window method through the first light-transmitting window 334. On the other hand, the No. III scintillation crystal 330 is coupled with a first photoelectric sensor 110 and a second photoelectric sensor 210. When the No. III scintillation crystal 330 is struck by a γ photon, the generated visible light can be detected by the coupled first photoelectric sensor 110 and second photoelectric sensor 210. Based on the ratio of visible light detected by the first photoelectric sensor 110 and the second photoelectric sensor 210, the DOI information of the No. III scintillation crystal 330 can be calculated using the two-end method.

[0039] Taking a scintillation crystal 330 coupled with a second photoelectric sensor 210 as an example, among adjacent scintillation crystals 330, there is one scintillation crystal 330 coupled with another second photoelectric sensor 210. The second photoelectric sensors 210 coupled to these two scintillation crystals 330 are also adjacent to each other. The opposite sides of these two scintillation crystals 330 are called second side surfaces 332. That is, a side surface can include a second side surface 332 located between two adjacent second photoelectric sensors 210. A second light-transmitting window 335 can be provided on the second side surface 332 at a position away from the second end 320. Figure 2Taking scintillation crystals 330 I and II as examples, when scintillation crystal 330 I is struck by a gamma photon, it generates visible light. This visible light is detected by the second photoelectric sensor 210 coupled to scintillation crystal 330 I. A portion of this visible light passes through the second transparent window 335 to reach scintillation crystal 330 II, where it is also detected by the second photoelectric sensor 210 coupled to scintillation crystal 330 II. Based on the ratio of visible light detected by these two second photoelectric sensors 210, the DOI information of scintillation crystal 330 I can be calculated. Thus, this detector 10 can calculate the DOI using the window method through the second transparent window 335. On the other hand, the No. I scintillation crystal 330 is coupled with a first photoelectric sensor 110 and a second photoelectric sensor 210. When the No. I scintillation crystal 330 is struck by a γ photon, the generated visible light can be detected by the coupled first photoelectric sensor 110 and second photoelectric sensor 210. Based on the ratio of visible light detected by the first photoelectric sensor 110 and the second photoelectric sensor 210, the DOI information of the No. I scintillation crystal 330 can be calculated using the two-end method.

[0040] The scintillation crystals 330 I, II, III, and IV described above are merely examples for illustrative purposes, and the scintillation crystal 330 capable of simultaneously implementing both the window method and the two-end method for calculating DOI is not limited to these. Furthermore, this invention does not impose specific limitations on the arrangement of the crystal array 300, the first sensor array 100, and the second sensor array 200. It is understood that there can still be various other positional relationships between the first sensor array 100, the second sensor array 200, and the crystal array 300.

[0041] The detector 10 provided by this invention can simultaneously calculate the DOI information of the scintillation crystal 330 using both the window method and the two-end method. The calculation results can be cross-referenced. Specifically, when the obtained reaction position is close to the central region of the scintillation crystal 330, the DOI information calculated using the window method has stronger reference significance; conversely, when the obtained reaction position is close to both ends of the scintillation crystal 330, the DOI information calculated using the two-end method has stronger reference significance. This allows for higher accuracy in the final fitted result and overcomes the problems of low accuracy when calculating the DOI information using the window method when the reaction position is close to both ends of the scintillation crystal 330, and low accuracy when calculating the DOI information using the two-end method when the reaction position is close to the central region of the scintillation crystal 330. Compared to using either the window method or the two-end method alone to calculate the DOI of the scintillation crystal 330, this detector 10 can calculate the DOI information of the scintillation crystal 330 with higher accuracy, higher spatial resolution, and better detection performance.

[0042] The detector 10 of the present invention will be described in detail below with reference to several embodiments.

[0043] like Figure 2 , Figure 3 and Figure 4 As shown, in one embodiment of the present invention, the crystal array 300 is a 12×12 array, and the size of each scintillation crystal 330 can be X×Y. The first sensor array 100 is a 3×3 array, and the size of each first photoelectric sensor 110 can be 4X×4Y. The second sensor array 200 is a 2×2 array, and the size of the second photoelectric sensor 210 can also be 4X×4Y. The first sensor array 100 exactly covers the first end 310 of the crystal array 300, and the second sensor array 200 covers the middle region 340 of the second end 320 of the crystal array 300. In the X direction shown in the figure, the edge of the second sensor array 200 is separated from the edge of the crystal array 300 by two rows of scintillation crystals 330. In the YY direction shown in the figure, the edge of the second sensor array 200 is separated from the edge of the crystal array 300 by two rows of scintillation crystals 330. Thus, the central region 340 of the crystal array 300 is an 8×8 array, and photoelectric sensors are coupled to both ends of the scintillation crystal 330 in the central region 340. This means that the scintillation crystal 330 in the central region 340 can perform DOI calculation using the two-end method. (See also...) Figure 3 Since the first sensor array 100 completely covers the first end 310 of the crystal array 300, all the first light-transmitting windows 334 can be used to calculate the DOI. In other words, the scintillation crystals 330 on both sides of all the first light-transmitting windows 334 can calculate the DOI using the window method. On the other hand, see... Figure 4 The second sensor array 200 only covers the middle region 340 of the second end 320 of the crystal array 300. Only the second light-transmitting window 335 located in the middle region 340 can be used to calculate DOI. In other words, the scintillation crystals 330 located on both sides of the second light-transmitting window 335 in the middle region 340 can realize the window method to calculate DOI.

[0044] like Figure 5 and Figure 6As shown, in one embodiment of the present invention, the crystal array 300 is a 12×12 array, and the size of each scintillation crystal 330 can be X×Y. The first sensor array 100 is a 3×3 array, and the size of each first photoelectric sensor 110 can be 4X×4Y. The second sensor array 200 is a 4×4 array, and the size of the second photoelectric sensor 210 can also be 4X×4Y. The first sensor array 100 exactly covers the first end 310 of the crystal array 300. The second sensor array 200 covers the second end 320 of the crystal array 300, and the second sensor array 200 has a coverage area 230 covering the second end 320 of the crystal array 300 and an extension area 220 extending beyond the crystal array 300. In the X direction shown in the figure, the edge of the second sensor array 200 is spaced two rows of scintillation crystals 330 from the edge of the crystal array 300. In the YY direction shown in the figure, the edge of the second sensor array 200 extends beyond the edge of the crystal array 300 by a distance of two rows of scintillation crystals 330. In this way, all scintillation crystals 330 of the crystal array 300 can perform DOI calculation using the two-end method. (See also...) Figure 5 Since the first sensor array 100 completely covers the first end 310 of the crystal array 300, all the first light-transmitting windows 334 can be used to calculate the DOI. In other words, the scintillation crystals 330 on both sides of all the first light-transmitting windows 334 can calculate the DOI using the window method. On the other hand, see... Figure 6 The second sensor array 200 also completely covers the second end 320 of the crystal array 300. All the second light-transmitting windows 335 can be used to calculate DOI. In other words, the scintillation crystals 330 on both sides of all the second light-transmitting windows 335 can realize the window method to calculate DOI.

[0045] like Figure 7 and Figure 8As shown, in one embodiment of the present invention, the crystal array 300 is a 12×12 array, and the size of each scintillation crystal 330 can be X×Y. The first sensor array 100 is a 3×3 array, and the size of each first photoelectric sensor 110 can be 4X×4Y. The second sensor array 200 is a 4×2 rectangular array, and the size of the second photoelectric sensor 210 can also be 4X×4Y. The first sensor array 100 exactly covers the first end 310 of the crystal array 300. The second sensor array 200 covers the middle region 340 of the second end 320 of the crystal array 300 in the XX direction shown in the figure, that is, the crystal array 300 has a middle region 340 coupled with the second photoelectric sensor 210 and a surrounding region 350 not coupled with the second photoelectric sensor 210 in the XX direction shown in the figure. The second sensor array 200 has a portion covering the crystal array 300 and an overhanging region 220 extending beyond the crystal array 300 in the YY direction shown in the figure. In the XX direction shown in the figure, the edge of the second sensor array 200 is separated from the edge of the crystal array 300 by two rows of scintillation crystals 330. In the YY direction shown in the diagram, the edge of the second sensor array 200 extends beyond the edge of the crystal array 300 by the distance between the two rows of scintillation crystals 330. Both ends of the scintillation crystals 330 in the central region 340 are coupled to photoelectric sensors; therefore, the DOI of all scintillation crystals 330 in the central region 340 can be calculated using the two-end method. See also... Figure 7 Since the first sensor array 100 completely covers the first end 310 of the crystal array 300, all the first light-transmitting windows 334 can be used to calculate the DOI. In other words, the scintillation crystals 330 on both sides of all the first light-transmitting windows 334 can calculate the DOI using the window method. (See also...) Figure 8 The second sensor array 200 only covers the middle region 340 of the second end 320 of the crystal array 300 in the XX direction shown in the figure. Only the second light-transmitting window 335 located in the middle region 340 can be used to calculate DOI. That is to say, the scintillation crystals 330 located on both sides of the second light-transmitting window 335 in the middle region 340 can realize the window method to calculate DOI.

[0046] See also Figure 3 , Figure 5 and Figure 7In the three embodiments provided by this invention, the scintillation crystal 330 can have a size of X×Y, and the first photoelectric sensor 110 can have a size of 4X×4Y. The dimensions referred to are the dimensions in the XX direction and the YY direction shown in the figure. As shown, one first photoelectric sensor 110 can be coupled with sixteen scintillation crystals 330. In both the XX and YY directions, the size ratio of the first photoelectric sensor 110 to the scintillation crystal 330 is 1:4. When used for detecting small animals, the overall size of the detector needs to be small, which actually requires the use of smaller scintillation crystals and photoelectric sensors. For calculating DOI using the window method, in existing detector devices, the photoelectric sensor and scintillation crystal are arranged as shown in the figure. In both the XX and YY directions, one photoelectric sensor can be coupled with a maximum of four scintillation crystals. That is, in both the XX and YY directions, the size ratio of the photoelectric sensor to the scintillation crystal is at least 1:2. Otherwise, at least a portion of the scintillation crystals coupled to the photoelectric sensor cannot achieve DOI calculation using the window method, which would reduce the spatial resolution of the overall device. Due to limitations in photoelectric sensor technology and cost, even when using the smallest photoelectric sensor available in the prior art, if the size ratio of the photoelectric sensor to the scintillation crystal is 1:2, the size of the scintillation crystal is still relatively large. The detector 10 provided by this invention allows for a size ratio of 1:4 between the first photoelectric sensor 110 and the scintillation crystal 330, thereby enabling the use of a smaller scintillation crystal 330 and consequently, a smaller overall device for application in small animal PET detection.

[0047] Similarly, see Figure 4 , Figure 6 and Figure 8 The second photoelectric sensor 210 can also be 4X×4Y in size. These dimensions refer to the dimensions in the XX direction and the YY direction as shown in the figure. As illustrated, one second photoelectric sensor 210 can be coupled with sixteen scintillation crystals 330. In both the XX and YY directions, the size ratio of the second photoelectric sensor 210 to the scintillation crystals 330 is 1:4. This allows the first photoelectric sensor 110, the second photoelectric sensor 210, and the scintillation crystals 330 to all have relatively small dimensions, further enabling a smaller overall device. Such a detector 10 performs better when applied to small animal PET scans.

[0048] See again Figure 3 , Figure 5 and Figure 7The size of the crystal array 300 can be A1×B1, and the size of the first sensor array 100 can be A2×B2, where A2 = A1 and B2 = B1. In the case where the crystal array 300 is a 12×12 array, each scintillation crystal 330 has a size of X×Y, the first sensor array 100 is a 3×3 array, and each first photoelectric sensor 110 has a size of 4X×4Y, then A2 = A1 = 12X and B2 = B1 = 12Y, so that the first end 310 of the crystal array 300 can be completely covered by the first sensor array 100. The first sensor array 100 can just cover the first end 310 of the crystal array 300. It is worth noting that the specific shape and size of the first photoelectric sensor 110, the specific shape and size of the scintillation crystal 330, and the size ratio between the first photoelectric sensor 110 and the scintillation crystal 330 are not limited here. Such a detector 10 can ensure that the visible light generated by each scintillation crystal 330 that is struck by a gamma photon can be detected by at least one first photoelectric sensor 110. This can avoid the situation where the event of gamma photon striking the scintillation crystal 330 is not detected, thus improving the detection efficiency of the detector 10.

[0049] See Figure 4 The size of the second sensor array 200 can be A3×B3, where A3 < A1 and B3 < B1. In the case where the crystal array 300 is a 12×12 array, each scintillation crystal 330 is X×Y in size, the second sensor array 200 is a 2×2 array, and the second photoelectric sensor 210 is 4X×4Y in size, then A1 = 12X, B1 = 12Y, A3 = 8X, and B3 = 8Y. This allows the crystal array 300 at its second end 320 to be divided into a central region 340 covered by the second sensor array 200 and a surrounding region 350 not covered by the second sensor array 200. (See also...) Figure 2 The side may include a third side 333 located between the central region 340 and the surrounding region 350. The third side 333 may have a third light-transmitting window 336 positioned away from the second end 320. Third light-transmitting windows 336 may also be positioned at other locations on the crystal array 300. When the detector 10 needs to expand its detection range, it only needs to connect additional second photoelectric sensors 210 to increase the number of scintillation crystals 330 capable of calculating DOI using both the window method and the two-end method. In this case, the third light-transmitting window 336 can function similarly to the second light-transmitting window 335, thereby expanding the detection range of the detector 10.

[0050] See again Figure 4The scintillation crystal 330 can be X×Y in size, and the crystal array 300 can have a first direction (i.e., the XX direction in the diagram) and a second direction (i.e., the YY direction in the diagram) that are perpendicular to each other. The distance between the outer edge of the peripheral region 350 and the outer edge of the central region 340 in the first direction can be 2X, and the distance between the outer edge of the peripheral region 350 and the outer edge of the central region 340 in the second direction can be 2Y. For ease of description, the first direction mentioned below refers to the XX direction in the diagram, and the second direction refers to the YY direction in the diagram. Specifically, the scintillation crystals 330 are arranged in multiple rows and columns, the crystal array 300 is arranged in a square, and the second sensor array 200 is coupled to the central region 340 of the second end 320 of the crystal array 300. The central region 340 and the peripheral region 350 are spaced apart by two rows or two columns of scintillation crystals 330 in both the XX and YY directions. Such a detector 10 is more regular, and multiple detectors 10 can be spliced ​​together to achieve a larger detection range.

[0051] See Figure 5 and Figure 6 The size of the crystal array 300 can be A1×B1, and the size of the first sensor array 100 can be A2×B2, where A2 = A1 and B2 = B1, so that the first end 310 of the crystal array 300 can be completely covered by the first sensor array 100. The size of the second sensor array 200 can be A4×B4, where A4 > A1 and B4 > B1. In the case where the crystal array 300 is a 12×12 array, each scintillation crystal 330 is X×Y in size, the second sensor array 200 is a 4×4 array, and the second photoelectric sensor 210 is 4X×4Y in size, then A1 = 12X, B1 = 12Y, A4 = 16X, and B4 = 16Y, so that the second sensor array 200 can have a coverage area 230 covering the crystal array 300 and an extension area 220 extending beyond the crystal array 300. The coverage area 230 can have the same size and shape as the second end 320 of the crystal array 300, and the extension area 220 can have various shapes and sizes. The coverage area 230 and the overlay area 220 are merely partitions on the second sensor array 200 for ease of description. In reality, the second photoelectric sensors 210 located in the overlay area 220 and the coverage area 230 are not specifically limited by their position. Multiple second photoelectric sensors 210, regardless of whether they are located in the overlay area 220 or the coverage area 230, can still be the same photoelectric sensor or different photoelectric sensors. The design of the overlay area 220 ensures that the second sensor array 200 completely covers the second end 320 of the crystal array 300. Therefore, even when the first sensor array 100 also covers the first end 310 of the crystal array 300, it ensures that each scintillation crystal 330 can perform DOI calculation using the two-end method, thus improving the accuracy of the detector 10 in calculating DOI.

[0052] Furthermore, the scintillation crystal 330 can be X×Y in size, and the crystal array 300 can have a first direction (i.e., the XX direction in the diagram) and a second direction (i.e., the YY direction in the diagram) that are perpendicular to each other. The distance between the outer edge of the extended region 220 and the outer edge of the covered region 230 in the first direction can be 2X, and the distance between the outer edge of the extended region 220 and the outer edge of the covered region 230 in the second direction can be 2Y. Specifically, the scintillation crystals 330 are arranged in multiple rows and columns, the crystal array 300 is arranged in a square, and the second sensor array 200 is coupled to the second end 320 of the crystal array 300. The extended region 220 and the covered region 230 are spaced apart by two rows or two columns of scintillation crystals 330 in both the XX and YY directions. Such a detector 10 is more regular, and the multiple second photoelectric sensors 210 have the same shape and size, resulting in a simple structure and ease of production.

[0053] See also Figure 2 , Figure 7 and Figure 8 The size of the second sensor array 200 can be A5×B5, where A5 < A1 and B5 > B1. When the crystal array 300 is a 12×12 array, each scintillation crystal 330 is X×Y in size, the second sensor array 200 is a 2×4 array, and the size of the second photoelectric sensor 210 is 4X×4Y, then A1 = 12X, B1 = 12Y, A5 = 8X, and B5 = 16Y. This allows the crystal array 300 at the second end 320 to have at least a central region 340 covered by the second sensor array 200 and a surrounding region 350 not covered by the second sensor array 200. The side can include a third side 333 located between the central region 340 and the surrounding region 350. The third side 333 can have a third light-transmitting window 336 located away from the second end 320. When the detector 10 needs to expand its detection range, it only needs to add some second photoelectric sensors 210 to enable more scintillation crystals 330 to calculate DOI using the window method and the two-end method. At this time, the third light-transmitting window 336 can play the same role as the second light-transmitting window 335, thereby expanding the detection range of the detector 10.

[0054] See again Figure 2 , Figure 7 and Figure 8The scintillation crystal 330 has an X×Y dimension. The crystal array 300 can have a first direction and a second direction that are perpendicular to each other. The distance between the outer edge of the peripheral region 350 and the outer edge of the central region 340 in the first direction can be 2X. Furthermore, the second sensor array 200 can have an extension region 220 extending beyond the crystal array 300 in the second direction. The distance between the outer edge of the extension region 220 and the outer edge of the central region 340 in the second direction can be 2Y. Specifically, the scintillation crystals 330 are arranged in multiple rows and columns, the crystal array 300 is arranged in a square, and there are two columns of scintillation crystals 330 between the outer edge of the peripheral region 350 and the outer edge of the central region 340; there are two rows of scintillation crystals 330 between the outer edge of the extension region 220 and the outer edge of the central region 340. With more scintillation crystals 330 in the second direction (i.e., the YY direction shown in the figure), the detector 10 can realize the window method and the double-ended method to calculate the DOI, thereby improving the detection effect of the detector 10. Moreover, such a detector 10 can meet some practical needs. In the illustrated embodiment, the second sensor array 200 has an extension region 220 extending beyond the crystal array 300 in the second direction, while the crystal array 300 has a surrounding region 350 that is not coupled to the second photoelectric sensor 210 in the first direction. However, it is worth noting that in other embodiments, the second sensor array 200 may have an extension region 220 extending beyond the crystal array 300 in the first direction, while the crystal array 300 may have a surrounding region 350 that is not coupled to the second photoelectric sensor 210 in the second direction. Those skilled in the art can design the specific arrangement of the relative positions of the second sensor array 200 and the crystal array 300 according to the actual needs.

[0055] In several embodiments of this invention, the first photoelectric sensor 110 and the second photoelectric sensor 210 are staggered. This staggered arrangement ensures that there is at most one light-transmitting window on one side, for example, at most one first light-transmitting window 334 on one first side 331. This design avoids the interference that can occur when multiple light-transmitting windows are located on the same side and used for window-based DOI calculation. Therefore, this detector 10 is more convenient for data processing and provides better detection results.

[0056] In the embodiments given above, the crystal array 300 can have a first direction (i.e., the XX direction in the diagram) and a second direction (i.e., the YY direction in the diagram) that are perpendicular to each other. The first photoelectric sensor 110 can be offset from the second photoelectric sensor 210 by two scintillation crystals 330 in the first direction and / or the second direction. Specifically, the scintillation crystals 330 are arranged in multiple rows and columns, and the crystal array 300 is arranged in a square. The first photoelectric sensor 110 and the second photoelectric sensor 210 are spaced apart by two rows or two columns of scintillation crystals 330 in both the XX and YY directions. This allows the size ratio of the first photoelectric sensor 110 and the second photoelectric sensor 210 relative to the scintillation crystals 330 in both the first and second directions to be 1:4. This allows for a larger proportion of the scintillation crystals 330 in the total number of scintillation crystals in both the window method and the two-end method for calculating the DOI. Therefore, the detector 10 has a better detection effect.

[0057] It should be noted that although the first sensor array 100 and the second sensor array 200 are staggered in the above embodiments, in embodiments not shown, the first sensor array 100 and the second sensor array 200 may also be non-staggered. In this case, there may be a situation where two light-transmitting windows are provided on one side of a scintillation crystal 330. For example, a scintillation crystal 330 has a first photoelectric sensor 110 and a second photoelectric sensor 210 coupled to both ends, and the scintillation crystal 330 is located at the edges of both the first photoelectric sensor 110 and the second photoelectric sensor 210. That is, the first side 331 between two adjacent first photoelectric sensors 110 and the second side 332 between two adjacent second photoelectric sensors 210 on the scintillation crystal 330 are the same side. In this case, a first light-transmitting window 334 is provided on the first side 331 away from the first end 310, and a second light-transmitting window 335 is provided on the second side 332 away from the second end 320. That is, both the first light-transmitting window 334 and the second light-transmitting window 335 are provided on the same side. Such a scintillation crystal 330 can also simultaneously perform DOI calculations using both the window method and the two-end method.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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 detector, characterized in that, include: Multiple scintillation crystals form a crystal array, the crystal array having a first end and a second end, each scintillation crystal having a side surface located between the first end and the second end, the size of the crystal array being A1×B1; A plurality of first photoelectric sensors are provided, which form a first sensor array, and the first sensor array is coupled to the first end. as well as Multiple second photoelectric sensors form a second sensor array, which is coupled to the second end. The size of the second sensor array is A3×B3, where A3<A1 and B3<B1, so that the crystal array at the second end is divided into a central region covered by the second sensor array and a surrounding region not covered by the second sensor array. The side includes a first side located between two adjacent first photoelectric sensors and a second side located between two adjacent second photoelectric sensors. The first side has a first light-transmitting window located away from the first end, and the second side has a second light-transmitting window located away from the second end. The side also includes a third side located between the central area and the surrounding area, and the third side has a third light-transmitting window located away from the second end.

2. The detector according to claim 1, characterized in that, The scintillation crystal has a size of X×Y, and the first photoelectric sensor has a size of 4X×4Y.

3. The detector according to claim 2, characterized in that, The dimensions of the second photoelectric sensor are 4X×4Y.

4. The detector according to claim 1, characterized in that, The size of the first sensor array is A2×B2, where A2=A1 and B2=B1, so that the crystal array is completely covered by the first sensor array at the first end.

5. The detector according to claim 4, characterized in that, The scintillation crystal has a size of X×Y, the crystal array has a first direction and a second direction that are perpendicular to each other, the distance between the outer edge of the surrounding area and the outer edge of the central area in the first direction is 2X, and the distance between the outer edge of the surrounding area and the outer edge of the central area in the second direction is 2Y.

6. The detector according to claim 4, characterized in that, The second sensor array has a size of A4×B4, where A4>A1 and B4>B1, so that the second sensor array has a coverage area that covers the crystal array and an overlay area that extends beyond the crystal array.

7. The detector according to claim 6, characterized in that, The scintillation crystal has a size of X×Y, the crystal array has a first direction and a second direction that are perpendicular to each other, the distance between the outer edge of the overlay area and the outer edge of the cover area in the first direction is 2X, and the distance between the outer edge of the overlay area and the outer edge of the cover area in the second direction is 2Y.

8. The detector according to claim 4, characterized in that, The second sensor array has a size of A5×B5, where A5 < A1 and B5 > B1, such that the crystal array at the second end has at least a central region covered by the second sensor array and a surrounding region not covered by the second sensor array. The side includes a third side located between the central region and the surrounding region, and the third side has a third light-transmitting window disposed at a position away from the second end.

9. The detector according to claim 8, characterized in that, The scintillation crystal has a size of X×Y, the crystal array has a first direction and a second direction that are perpendicular to each other, the distance between the outer edge of the surrounding area and the outer edge of the central area in the first direction is 2X; and the second sensor array has an extension area in the second direction that extends beyond the crystal array, the distance between the outer edge of the extension area and the outer edge of the central area in the second direction is 2Y.

10. The detector according to claim 3, characterized in that, The first photoelectric sensor and the second photoelectric sensor are misaligned.

11. The detector according to claim 10, characterized in that, The crystal array has a first direction and a second direction that are perpendicular to each other, and the first photoelectric sensor is offset from the second photoelectric sensor by two scintillation crystals in the first direction and / or the second direction.

12. A transmission imaging device, characterized in that, It includes a processor module and a detector as described in any one of claims 1-11, wherein a plurality of first photoelectric sensors and a plurality of second photoelectric sensors are respectively electrically connected to the processor module.

Images