CN116449411A

CN116449411A - Detector and emission imaging device

Info

Publication number: CN116449411A
Application number: CN202310566306.2A
Authority: CN
Inventors: 于昕; 张恒; 朱志良; 张义彬; 谢思维; 曾家旸; 彭旗宇
Original assignee: Shenzhen Bay Laboratory
Current assignee: Shenzhen Bay Laboratory
Priority date: 2023-05-18
Filing date: 2023-05-18
Publication date: 2023-07-18

Abstract

The invention provides a detector and an emission imaging device. The detector includes a plurality of scintillation crystals forming a crystal array having a first end and a second end, the scintillation crystals having sides between the first end and the second end; a plurality of first photosensors forming a first sensor array, the first sensor array coupled to the first end; and a plurality of second photosensors forming a second sensor array, the second sensor array coupled to the second end; the side surfaces comprise a first side surface positioned between two adjacent first photoelectric sensors and a second side surface positioned between two adjacent second photoelectric sensors, wherein the first side surface is provided with a first light-transmitting window at a position far away from a first end, and the second side surface is provided with a second light-transmitting window at a position far away from a second end. The detector can calculate DOI with higher precision by using a window method and a double-end method simultaneously, and has higher spatial resolution.

Description

Detector and emission imaging device

Technical Field

The invention relates to the technical field of emission imaging equipment, in particular to a detector and emission imaging equipment.

Background

With the increasing level of science and technology, there are increasing means by which people deal with complex conditions. The computed tomography technology is a major breakthrough in the field of nuclear medicine imaging equipment. Emission computed tomography (Emission Computed Tomography, ECT) is also known as radionuclide computed tomography, and is a imaging technique capable of displaying distribution and stereoscopic images of radionuclides at various levels in the human body. ECT can detect metabolic and blood flow states of an organ and is a dynamic, functional imaging technique. Currently, positron emission tomography (Positron Emission Computed Tomography, hereinafter referred to as PET) is a relatively popular ECT technique.

In the prior art, a window method or a double-ended method is generally used to obtain reaction depth information (Depth Of Interaction, hereinafter referred to as DOI). In the window method, a light transmission window is arranged at one end of the detector far away from the photoelectric sensor, when a certain scintillation crystal detects gamma photons, generated visible light can be transmitted to the photoelectric sensor coupled with the scintillation crystal, part of the visible light can be transmitted to another adjacent photoelectric sensor through the light transmission window, the more the reaction position is far away from the photoelectric sensor coupled with the scintillation crystal, the more the visible light detected by the other adjacent photoelectric sensor is, and DOI can be calculated according to the proportion of the visible light detected by the two photoelectric sensors. In the double-end method, photoelectric sensors are arranged at two ends of a detector, when a certain scintillation crystal detects gamma photons, generated visible light can be transmitted to two photoelectric sensors coupled with two ends of the scintillation crystal, and according to different positions of the scintillation crystal where the gamma photons are detected, the proportion of the visible light detected by the two photoelectric sensors is also different, wherein more visible light can be detected by the photoelectric sensors which are closer to the position where the scintillation crystal detects the gamma photons, so that DOI can be calculated.

In the existing design of calculating DOI by the double-end method, the side surface of the scintillation crystal needs to be fully paved with a reflecting layer, and in the existing design of calculating DOI by the window method, the side surface of the scintillation crystal needs to be provided with a light-transmitting window, so that the two designs are contradictory. In addition, for the window method, when the position of the gamma photon detected by the scintillation crystal is close to two ends, the generated visible light is transmitted to the two photoelectric sensors almost equally, so that DOI accuracy obtained by calculating the proportion of the visible light detected by the two photoelectric sensors is poor; on the other hand, for the double-end method, when the position of the scintillation crystal for detecting gamma photons is located in the middle depth part, the generated visible light is transmitted to the two photoelectric sensors almost equally, so that the DOI precision obtained by calculating the proportion of the visible light detected by the two photoelectric sensors is poor.

Disclosure of Invention

In order to at least partially solve the problems of 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 having a first end and a second end, the scintillation crystals having sides between the first end and the second end; a plurality of first photosensors forming a first sensor array, the first sensor array coupled to the first end; and a plurality of second photosensors forming a second sensor array, the second sensor array coupled to the second end; the side surfaces comprise a first side surface positioned between two adjacent first photoelectric sensors and a second side surface positioned between two adjacent second photoelectric sensors, wherein the first side surface is provided with a first light-transmitting window at a position far away from a first end, and the second side surface is provided with a second light-transmitting window at a position far away from a second end.

The detector provided by the invention can calculate the DOI information of the scintillation crystal by utilizing the window method and the double-end method simultaneously, and the calculation results can be mutually referred, wherein the DOI information calculated by the window method has stronger reference meaning when the obtained reaction position is close to the middle region of the scintillation crystal, and the DOI information calculated by the double-end method has stronger reference meaning when the obtained reaction position is close to the two end regions of the scintillation crystal, so that the final result obtained by fitting has higher precision, the problem that the precision of calculating the DOI information by utilizing the window method is low when the reaction position is close to the two end regions of the scintillation crystal is solved, and the problem that the precision of calculating the DOI information by utilizing the double-end method is low when the reaction position is close to the middle region of the scintillation crystal is solved. Compared with the method of calculating the DOI of the scintillation crystal by using a window method or a double-end method alone, the detector can calculate the DOI information of the scintillation crystal with higher precision, has higher spatial resolution and better detection effect.

Illustratively, the scintillator crystal is sized x×y and the first photosensor is sized 4x×4Y. The size ratio of the first photoelectric sensor to the scintillation crystal in the detector provided by the invention can be 1:4, whereby smaller size scintillation crystals can be used, and the overall device can then be of smaller size for use in small animal PET detection.

Illustratively, the second photosensor is 4X 4Y in size. Thus, the first photoelectric sensor, the second photoelectric sensor and the scintillation crystal can have smaller sizes, so that the whole device can have smaller sizes, and the detector can be better applied to PET detection of small animals.

Illustratively, the crystal array has a size a1×b1 and the first sensor array has a size a2×b2, a2=a1, b2=b1 such that the crystal array is completely covered by the first sensor array at the first end. The detector can ensure that the visible light generated by each scintillation crystal impacted by gamma photons can be detected by at least one first photoelectric sensor, so that the condition that the event of the gamma photons impacting the scintillation crystal is not detected can be avoided, and the detection efficiency of the detector is improved.

Illustratively, the second sensor array has a size a3×b3, A3 < A1, B3 < B1 such that the crystal array is divided at the second end into a middle region covered by the second sensor array and a peripheral region not covered by the second sensor array, the sides including a third side between the middle region and the peripheral region, the third side being provided with a third light transmissive window at a position remote from the second end. When the detector needs to expand the detection range, only a plurality of second photoelectric sensors are needed to be connected in a supplementing mode, so that more scintillation crystals for calculating DOI by a window method and a double-end method can be realized, and the third light-transmitting window can play the same role as the second light-transmitting window, so that the detection range of the detector is expanded.

Illustratively, the scintillation crystal has a dimension of X Y, the crystal array has a first direction and a second direction perpendicular to each other, the outer edge of the surrounding region is a distance of 2X in the first direction from the outer edge of the middle region, and the outer edge of the surrounding region is a distance of 2Y in the second direction from the outer edge of the middle region. Such a detector is more regular, and multiple detectors can be spliced to achieve a larger detection range.

Illustratively, the second sensor array has a size A4B 4, A4 > A1, B4 > B1 such that the second sensor array has a footprint that covers the crystal array and an overrun zone that extends beyond the crystal array. The design of the out-of-range area can ensure that the second sensor array completely covers the second end of the crystal array, so that under the condition that the first sensor array also covers the first end of the crystal array, each scintillation crystal can be ensured to realize double-end method DOI calculation, and the accuracy of the detector for DOI calculation is improved.

Illustratively, the scintillation crystal has a dimension of X X Y, the crystal array has a first direction and a second direction perpendicular to each other, the outer edge of the overrun zone is 2X from the outer edge of the footprint in the first direction, and the outer edge of the overrun zone is 2Y from the outer edge of the footprint in the second direction. The detector is more regular, the plurality of second photoelectric sensors have the same shape and size, the structure is simple, and the production is convenient.

Illustratively, the second sensor array has a size of A5×B5, A5 < A1, B5 > B1 such that the crystal array has at least a central region covered by the second sensor array and a peripheral region uncovered by the second sensor array at the second end, the sides including a third side between the central region and the peripheral region, the third side being provided with a third light transmissive window at a location remote from the second end. When the detector needs to expand the detection range, only a plurality of second photoelectric sensors are needed to be connected in a supplementing mode, so that more scintillation crystals for calculating DOI by a window method and a double-end method can be realized, and the third light-transmitting window can play the same role as the second light-transmitting window, so that the detection range of the detector is expanded.

Illustratively, the scintillation crystal has a size of X Y, the crystal array has a first direction and a second direction perpendicular to each other, and the outer edge of the peripheral region is spaced from the outer edge of the central region by a distance of 2X in the first direction; and the second sensor array has an excess region outside the crystal array in the second direction, and the distance between the outer edge of the excess region and the outer edge of the middle region in the second direction is 2Y. The detector has more scintillation crystals in the second direction, so that DOI can be calculated by a window method and a double-end method, and the detection effect of the detector is improved.

The first and second photosensors are illustratively offset. The design can avoid that a plurality of light-transmitting windows are arranged on the same side face, and the plurality of light-transmitting windows can interfere with each other when being used for calculating DOI by a window method. Therefore, the detector is more convenient to use and process data, and has good detection effect.

The crystal array has a first direction and a second direction perpendicular to each other, the first photosensor being offset by two scintillation crystals in the first direction and/or the second direction relative to the second photosensor. In this way, the dimension ratio of the first photoelectric sensor and the second photoelectric sensor relative to the scintillation crystal in the first direction and the second direction is 1:4, the ratio of the scintillation crystal for calculating DOI by the window method and the double-end method in all the scintillation crystals is larger, so that the detection effect of the detector is better.

According to another aspect of the present invention, there is also provided an emission imaging device. The emission imaging device includes a processor module and any of the detectors described above, with the plurality of first photosensors and the plurality of second photosensors being respectively electrically connected with the processor module. In such an emission imaging device, since the detector can calculate DOI with high accuracy, the overall device detection result has higher accuracy.

In the summary, a series of concepts in a simplified form are introduced, which will be further described in detail in the detailed description section. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

Advantages and features of the invention are described in detail below with reference to the accompanying drawings.

Drawings

The following drawings are included to provide an understanding of the invention and are incorporated in and constitute a part of this specification. Embodiments of the present invention and their description are shown in the drawings to explain the principles of the invention. In the drawings of which there are shown,

fig. 1 is a schematic diagram of an emissive imaging device according to an exemplary embodiment of the present invention;

FIG. 2 is a cross-sectional view of a detector according to an exemplary embodiment of the invention;

FIG. 3 is a top view of a detector according to an exemplary embodiment of the present invention;

FIG. 4 is a bottom view of the probe shown in FIG. 3;

FIG. 5 is a top view of a detector according to an exemplary embodiment of the invention;

FIG. 6 is a bottom view of the probe shown in FIG. 5;

FIG. 7 is a top view of a detector according to an exemplary embodiment of the invention; and

Fig. 8 is a bottom view of the probe shown in fig. 7.

Wherein the above figures include the following reference numerals:

10. a detector; 100. a first sensor array; 110. a first photosensor; 200. a second sensor array; 210. a second photosensor; 220. an overrun zone; 230. a coverage area; 300. a crystal array; 310. a first end; 320. a second end; 330. a scintillation crystal; 331. a first side; 332. a second side; 333. a third side; 334. a first light-transmitting window; 335. a second light-transmitting window; 336. a third light-transmitting window; 337. a light reflecting layer; 340. a middle region; 350. a peripheral region; 20. an emission imaging device; 400. a processor module; 30. and a detection ring.

Detailed Description

In the following description, numerous details are provided to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the following description illustrates preferred embodiments of the invention by way of example only and that the invention may be practiced without one or more of these details. Furthermore, some technical features that are known in the art have not been described in detail in order to avoid obscuring the invention.

According to one aspect of the invention, a detector is provided that may include a plurality of scintillation crystals, a plurality of first photosensors, and a plurality of second photosensors, wherein the plurality of scintillation crystals may form a crystal array, the plurality of first photosensors may form a first sensor array, and the plurality of second photosensors may form a second sensor array. A scintillation crystal refers to a crystal that converts the energy of energetic particles into optical energy under the impact of gamma photons. The scintillation crystal may be lutetium yttrium silicate scintillation crystal (LYSO crystal), bismuth germanate scintillation crystal (BGO crystal), cerium doped lutetium silicate scintillation crystal (LSO crystal), gadolinium silicate scintillation crystal (GSO crystal), sodium iodide scintillation crystal (NaI crystal), or crystals of various other materials. The plurality of scintillation crystals can be closely arranged to form a crystal array, and the whole formed crystal array can be in various shapes such as rectangle, circle or trapezoid. The first and second photosensors may each be of various types, existing or likely to occur in the future, such as photomultiplier tubes (PMTs), silicon photomultipliers (sipms), and so forth. The plurality of first photoelectric sensors can be closely arranged to form a first sensor array, and the formed first sensor array can be in various shapes such as rectangle, circle or trapezoid. The plurality of second photoelectric sensors can be closely arranged to form a second sensor array, and the formed second sensor array can be in various shapes such as rectangle, circle or trapezoid. The first photosensor, the first sensor array, the second photosensor, and the second sensor array are described in detail below.

According to another aspect of the present invention, an emissive imaging device is provided. Referring to fig. 1, the emission imaging device 20 may include a processor module 400 and any one of the detectors 10 described below, and the plurality of first photosensors 110 and the plurality of second photosensors 210 may be electrically connected with the processor module 400, respectively. The emission imaging device 20 may include a detection ring 30. Fig. 1 shows an enlarged view of the probe ring 30. The detector ring 30 may have a plurality of any of the detectors 10 arranged thereon as described below. Typically, the plurality of detectors 10 forming one detector ring 30 have substantially the same structure. The present application does not exclude embodiments in which different probes form one probe ring 30. A plurality of detection rings 30 may be closely arranged in a direction perpendicular to the paper surface. The detection space enclosed by these detection rings 30 can accommodate the object to be measured. Typically, the detection space may be substantially cylindrical. Of course, embodiments in which the detection space has other shapes are not excluded from the present application. The plurality of detectors 10 may be arranged in pairs, the pairs of detectors 10 being functional under PET imaging. In such an emission imaging device 20, since the detector 10 can calculate DOI with high accuracy, the overall device detection result has higher accuracy.

Referring to fig. 2, a 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 living being to be detected during detection, and the second end 320 may be the other end of the crystal array 300 that is farther from the living being to be detected. The crystal array 300 is turned over, and the second end 320 may be the end of the detector 10 that is closer to the living being to be detected during detection, and the first end 310 may be the other end of the crystal array 300 that is farther from the living being to be detected. It should be noted that the first end 310 and the second end 320 are not specifically defined herein, but merely serve as a distinction between two ends of the crystal array 300. For ease of description, the end of crystal array 300 near the upper portion in the Z-Z direction is referred to as a first end 310, and the other end of crystal array 300 near the lower portion in the Z-Z direction is referred to as a second end 320.

The scintillation crystal 330 can have sides between the first end 310 and the second end 320. The scintillation crystal 330 is generally rectangular parallelepiped, such scintillation crystal 330 having four sides between the first end 310 and the second end 320. The faces of the scintillation crystals 330 not coupled to the first or second photosensors 110, 210 may be provided with a light reflecting layer 337, and since the sides of the scintillation crystals 330 are faces not coupled to the first or second photosensors 110, 210, the sides of each of the scintillation crystals 330 may be covered with a light reflecting layer 337 reflecting light toward the inside of the corresponding scintillation crystal 330. The light reflection layer 337 can prevent the scintillation crystal 330 from being affected by scintillation light generated when the scintillation crystal 330 is impacted by gamma photons. The light reflecting layer 337 can improve the accuracy of detection when detecting scintillation light of a single scintillation crystal 330. The light-reflecting layer 337 may be formed by spraying, plating (e.g., spraying or silver plating), or pasting a light-reflecting material (e.g., ESR reflector). As a high-efficiency reflector, the reflectivity of ESR (Enhanced Specular Reflector) in the whole visible light spectrum range is more than 98%, which is higher than that of other types of reflectors at present. The ESR consists of a high polymer film layer, and is a more environment-friendly reflecting sheet material. The ESR retroreflective sheeting has a thickness of about 40 microns, for example 38 microns.

The plurality of first photosensors 110 may form a first sensor array 100, and the first sensor array 100 may be coupled to the first end 310. The plurality of second photosensors 210 may form a second sensor array 200, and the second sensor array 200 may be coupled to the second end 320. Coupled means that scintillation light signals can be transferred between the first sensor array 100 and/or the second sensor array 200 and the scintillation crystal 330. The first photoelectric sensor 110 and the second photoelectric sensor 210 can receive the scintillation light signal transmitted through the scintillation crystal 330, and further can convert the scintillation light signal into an electrical signal, the electrical signal can be used for data processing by a processor at the rear end, and visual images can be obtained through the data processing. The plurality of first photosensors 110 may have the same size and shape, or may have different sizes and shapes, and the plurality of first photosensors 110 may be closely arranged to form the first sensor array 100, or may have a gap therebetween. The plurality of second photosensors 210 are similar to the plurality of first photosensors 110, and are not described here. The first sensor array 100 is coupled to the first end 310, the second sensor array 200 is coupled to the second end 320, at least a portion of the scintillation crystals 330 in the crystal array 300 are simultaneously coupled with the first photosensor 110 and the second photosensor 210, the portion of the scintillation crystals 330 generate visible light when being impacted by gamma photons, the visible light can be detected by the coupled first photosensor 110 and second photosensor 210, and the DOI information of the scintillation crystals 330 impacted by gamma photons can be calculated according to the proportion of the visible light detected by the first photosensor 110 and the second photosensor 210. Thus, such a detector 10 may enable double-ended calculation of DOI.

Taking one scintillation crystal 330 coupled with the first photosensor 110 as an example, among the adjacent scintillation crystals 330 of the scintillation crystals 330, there is one scintillation crystal 330 coupled with the other first photosensor 110, the first photosensors 110 respectively coupled with the two scintillation crystals 330 are also adjacent to each other, and the opposite side surfaces of the two scintillation crystals 330 are the first side surface 331. That is, the sides may include a first side 331 between two adjacent first photosensors 110. The first side 331 may be provided with a first light transmissive window 334 at a location remote from the first end 310. Taking the example of the III scintillation crystal 330 and the IV scintillation crystal 330 marked in fig. 2, when the III scintillation crystal 330 is impacted by gamma photons, visible light can be generated, and the visible light can be detected by the first photosensor 110 coupled to the III scintillation crystal 330, wherein part of the visible light can reach the IV scintillation crystal 330 through the first light-transmitting window 334, so that the part of the visible light can be detected by the first photosensor 110 coupled to the IV scintillation crystal 330, and the DOI information of the III scintillation crystal 330 can be calculated according to the ratio of the visible light detected by the two first photosensors 110. Thus, such a detector 10 may implement windowed DOI calculation through the first light-transmitting window 334. On the other hand, the first and second photosensors 110 and 210 are simultaneously coupled to the III-scintillation crystal 330, and when the III-scintillation crystal 330 is impacted by gamma photons, the generated visible light can be detected by the coupled first and second photosensors 110 and 210, and the DOI information of the III-scintillation crystal 330 can be calculated by a double-ended method according to the ratio of the visible light detected by the first and second photosensors 110 and 210.

Taking one scintillation crystal 330 coupled with the second photosensor 210 as an example, in the adjacent scintillation crystals 330 of the scintillation crystals 330, there is one scintillation crystal 330 coupled with the other second photosensor 210, the second photosensors 210 respectively coupled with the two scintillation crystals 330 are also adjacent to each other, and the opposite side surfaces of the two scintillation crystals 330 are the second side surfaces 332. That is, the sides may include a second side 332 between two adjacent second photosensors 210. The second side 332 may be provided with a second light transmissive window 335 at a location remote from the second end 320. Taking the number I scintillation crystal 330 and the number II scintillation crystal 330 marked in fig. 2 as an example, when the number I scintillation crystal 330 is impacted by gamma photons, visible light can be generated, and the visible light can be detected by the second photosensor 210 coupled with the number I scintillation crystal 330, wherein part of the visible light can reach the number II scintillation crystal 330 through the second light-transmitting window 335, so that part of the visible light can be detected by the second photosensor 210 coupled with the number II scintillation crystal 330, and DOI information of the number I scintillation crystal 330 can be calculated according to the ratio of the visible light detected by the two second photosensors 210. Thus, such a detector 10 may implement windowed calculations DOI through the second light-transmissive window 335. On the other hand, the first and second photosensors 110 and 210 are simultaneously coupled to the I-number scintillation crystal 330, and when the I-number scintillation crystal 330 is impacted by gamma photons, the generated visible light can be detected by the coupled first and second photosensors 110 and 210, and the DOI information of the I-number scintillation crystal 330 can be calculated by a double-ended method according to the ratio of the visible light detected by the first and second photosensors 110 and 210.

The above-described I-number scintillation crystal 330, II-number scintillation crystal 330, III-number scintillation crystal 330, and IV-number scintillation crystal 330 are merely examples for convenience of explanation, and the scintillation crystal 330 capable of simultaneously implementing the window method and the double-ended method for DOI calculation is not limited thereto. In addition, the arrangement of the crystal array 300, the first sensor array 100 and the second sensor array 200 is not particularly limited, and it is understood that various other positional relationships between the first sensor array 100, the second sensor array 200 and the crystal array 300 are possible.

The detector 10 provided by the invention can calculate the DOI information of the scintillation crystal 330 by using a window method and a double-end method simultaneously, and the calculation results can be mutually referred, wherein the DOI information calculated by the window method has stronger reference meaning when the obtained reaction position is close to the middle area of the scintillation crystal 330, and the DOI information calculated by the double-end method has stronger reference meaning when the obtained reaction position is close to the two end areas of the scintillation crystal 330, so that the final result obtained by fitting has higher precision, the problem that the precision of calculating the DOI information by using the window method is low when the reaction position is close to the two end areas of the scintillation crystal 330 is solved, and the problem that the precision of calculating the DOI information by using the double-end method is low when the reaction position is close to the middle area of the scintillation crystal 330 is solved. Compared with the method of calculating the DOI of the scintillation crystal 330 by using a window method or a double-end method alone, the detector 10 can calculate the DOI information of the scintillation crystal 330 with higher precision, has higher spatial resolution and better detection effect.

The detector 10 of the present invention is described in detail below in connection with various embodiments.

As shown in fig. 2, 3, and 4, in one embodiment of the present invention, the crystal array 300 is a 12×12 array, and each scintillation crystal 330 can be x×y in size. The first sensor array 100 is a 3×3 array, and each first photosensor 110 may have a size of 4×4Y. The second sensor array 200 is a 2×2 array, and the second photosensor 210 may also have a size of 4×4Y. The first sensor array 100 covers just 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 illustrated X-X direction, the edge of the second sensor array 200 is spaced from the edge of the crystal array 300 by two columns of scintillation crystals 330. In the illustrated Y-Y direction, the edge of the second sensor array 200 is spaced from the edge of the crystal array 300 by two rows of scintillation crystals 330. Thus, the middle region 340 of the crystal array 300 is an 8 x 8 array, and the photosensors are coupled to both ends of the scintillation crystals 330 of the middle region 340, i.e., the scintillation crystals 330 of the middle region 340 can implement double-ended DOI calculation. Referring to fig. 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 DOI, that is, all the scintillation crystals 330 on both sides of the first light-transmitting windows 334 can implement the windowed calculation of DOI. On the other hand, referring to fig. 4, the second sensor array 200 covers only the middle region 340 of the second end 320 of the crystal array 300, and only the second light-transmitting window 335 located in the middle region 340 can be used to calculate DOI, that is, the scintillation crystals 330 located on both sides of the second light-transmitting window 335 in the middle region 340 can implement the windowed DOI calculation.

As shown in fig. 5 and 6, in one embodiment of the present invention, the crystal array 300 is a 12×12 array, and each scintillation crystal 330 may be x×y in size. The first sensor array 100 is a 3×3 array, and each first photosensor 110 may have a size of 4×4Y. The second sensor array 200 is a 4X 4 array, and the second photosensor 210 may also be 4X 4Y in size. The first sensor array 100 just covers the first end 310 of the crystal array 300. The second sensor array 200 overlies the second end 320 of the crystal array 300, and the second sensor array 200 has a footprint 230 overlying the second end 320 of the crystal array 300 and an excess region 220 that extends beyond the crystal array 300. In the illustrated X-X direction, the edge of the second sensor array 200 is spaced from the edge of the crystal array 300 by two columns of scintillation crystals 330. In the illustrated Y-Y direction, the edge of the second sensor array 200 is beyond the edge of the crystal array 300 by a distance of two rows of scintillation crystals 330. In this way, all of the scintillation crystals 330 of the crystal array 300 can implement a double-ended calculation of DOI. Referring to fig. 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 DOI, that is, all the scintillation crystals 330 on both sides of the first light-transmitting windows 334 can implement the windowed calculation of DOI. On the other hand, referring to fig. 6, the second sensor array 200 also completely covers the second end 320 of the crystal array 300, and all the second light-transmitting windows 335 can be used to calculate the DOI, that is, all the scintillation crystals 330 on both sides of the second light-transmitting windows 335 can implement the window method to calculate the DOI.

As shown in fig. 7 and 8, in one embodiment of the present invention, the crystal array 300 is a 12×12 array, and each scintillation crystal 330 may be x×y in size. The first sensor array 100 is a 3×3 array, and each first photosensor 110 may have a size of 4×4Y. The second sensor array 200 is a 4X 2 rectangular array, the second photosensor 210 may also be 4X 4Y in size. The first sensor array 100 just covers the first end 310 of the crystal array 300. The second sensor array 200 covers a middle region 340 of the second end 320 of the crystal array 300 in the illustrated X-X direction, i.e. the crystal array 300 has a middle region 340 coupled with the second photosensors 210 and a surrounding region 350 not coupled with the second photosensors 210 in the illustrated X-X direction. The second sensor array 200 has a portion overlying the crystal array 300 in the illustrated Y-Y direction and an excess region 220 beyond the crystal array 300. In the illustrated X-X direction, the edge of the second sensor array 200 is spaced from the edge of the crystal array 300 by two columns of scintillation crystals 330. In the illustrated Y-Y direction, the edge of the second sensor array 200 is beyond the edge of the crystal array 300 by a distance of two rows of scintillation crystals 330. The scintillating crystals 330 of the middle region 340 are coupled with photosensors at both ends, so that the scintillating crystals 330 of the middle region 340 can calculate DOI by a double-ended method. Referring to fig. 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 DOI, that is, all the scintillation crystals 330 on both sides of the first light-transmitting windows 334 can implement the windowed calculation of DOI. Referring to fig. 8, the second sensor array 200 covers only the middle region 340 of the second end 320 of the crystal array 300 in the X-X direction as shown, and only the second light-transmitting window 335 located in the middle region 340 can be used to calculate DOI, that is, the scintillation crystals 330 located on both sides of the second light-transmitting window 335 in the middle region 340 can implement the windowed calculation of DOI.

Referring to fig. 3, 5 and 7 in combination, in three embodiments of the present invention, the size of the scintillation crystal 330 may be x×y, and the size of the first photosensor 110 may be 4x×4Y. The dimensions are those in the X-X direction of the illustration and in the Y-Y direction of the illustration. As shown, sixteen scintillation crystals 330 can be coupled to one first photosensor 110, and the ratio of the dimensions of the first photosensor 110 and the scintillation crystals 330 in the X-X direction and the Y-Y direction is 1:4. when used for detection of small animals, the overall size of the detector needs to be small, and in practice, small-sized scintillation crystals and photosensors are required. In the conventional detector device, the photoelectric sensors and the scintillation crystals are arranged according to the diagram, and at most four scintillation crystals are coupled to one photoelectric sensor in the X-X direction and the Y-Y direction, namely, the dimension ratio of the photoelectric sensors to the scintillation crystals in the X-X direction and the Y-Y direction is 1 at the minimum: 2, otherwise, at least a part of the scintillation crystals coupled by the photoelectric sensor cannot realize window method DOI calculation, and the spatial resolution of the whole device is reduced. Due to the limitations of the technology and cost of the photosensor, when the photosensor with the smallest size in the prior art is used, if the size ratio of the photosensor to the scintillation crystal is 1:2, the size of the scintillation crystal is still large. The size ratio of the first photosensor 110 to the scintillation crystal 330 in the detector 10 provided by the present invention may be 1:4, whereby a smaller size scintillation crystal 330 can be used, and the overall device can then be of smaller size for use in small animal PET detection.

Similarly, referring to fig. 4, 6 and 8, the second photosensor 210 may also be 4X 4Y in size. The dimensions are those in the X-X direction of the illustration and in the Y-Y direction of the illustration. As shown, sixteen scintillation crystals 330 can be coupled to one second photosensor 210, and the second photosensor 210 and the scintillation crystals 330 have a dimension ratio of 1 in the X-X direction and the Y-Y direction: 4. thus, the first and second photosensors 110, 210 and the scintillation crystal 330 can each be of smaller size, further enabling the overall device to be of smaller size, such a detector 10 being better suited for use in small animal PET detection.

Referring again to fig. 3, 5 and 7 in combination, the crystal array 300 may be a1×b1 in size, the first sensor array 100 may be a2×b2 in size, a2=a1, b2=b1, and a2=a1 in the case where the crystal array 300 is a 12×12 array, each scintillation crystal 330 is an x×y in size, the first sensor array 100 is a 3×3 array, and each first photosensor 110 is a 4x×4Y in size, so that the crystal array 300 may be completely covered by the first sensor array 100 at the first end 310. The first sensor array 100 may just cover the first end 310 of the crystal array 300. It is noted that the specific shape and size of the first photosensor 110, the specific shape and size of the scintillation crystal 330, and the size ratio of the first photosensor 110 to the scintillation crystal 330 are not limited herein. Such a detector 10 can ensure that the visible light generated by each scintillation crystal 330 impacted by the gamma photons can be detected by at least one first photosensor 110, so that the condition that the event that the gamma photons impact the scintillation crystal 330 is not detected can be avoided, and the detection efficiency of the detector 10 is improved.

Referring to fig. 4, the second sensor array 200 may have a size a3×b3, a3 < A1, B3 < B1, and a1=12x, b1=12y, a3=8x, b3=8y, where the crystal array 300 is a 12×12 array, each of the scintillator crystals 330 has a size x×y, the second sensor array 200 is a 2×2 array, and the second photosensor 210 has a size of 4x×4y, so that the crystal array 300 may be divided into a middle region 340 covered by the second sensor array 200 and a peripheral region 350 not covered by the second sensor array 200 at the second end 320. Referring to fig. 2, the side surface may include a third side surface 333 between the middle region 340 and the peripheral region 350, and the third side surface 333 may be provided with a third light-transmitting window 336 at a position remote from the second end 320. A third light transmissive window 336 may also be provided at other locations on the crystal array 300. When the detection range of the detector 10 needs to be enlarged, only a plurality of second photoelectric sensors 210 need to be connected in a supplementing way, so that more scintillation crystals 330 for realizing the window method and the double-end method DOI calculation can be realized, and the third light-transmitting window 336 can play the same role as the second light-transmitting window 335, so that the detection range of the detector 10 is enlarged.

Referring again to fig. 4, the scintillation crystal 330 may be sized x×y, the crystal array 300 may have a first direction (i.e., X-X direction as illustrated) and a second direction (i.e., Y-Y direction as illustrated) perpendicular to each other, the outer edge of the peripheral region 350 may be 2X from the outer edge of the middle region 340 in the first direction, and the outer edge of the peripheral region 350 may be 2Y from the outer edge of the middle region 340 in the second direction. For ease of description, the first direction is referred to hereinafter as the illustrative X-X direction, and the second direction is referred to as the illustrative Y-Y direction. Specifically, the scintillation crystals 330 are arranged in a plurality of rows and columns, the crystal array 300 is arranged in a square shape, and the second sensor array 200 is coupled to a middle region 340 of the second end 320 of the crystal array 300, and the middle region 340 and the surrounding region 350 are each spaced apart by two rows or columns of the scintillation crystals 330 in the X-X direction and the Y-Y direction. Such a detector 10 is more regular, and a plurality of detectors 10 may be spliced to achieve a larger detection range.

Referring to fig. 5 and 6, the size of the crystal array 300 may be a1×b1, and the size of the first sensor array 100 may be a2×b2, a2=a1, b2=b1, such that the crystal array 300 may be completely covered by the first sensor array 100 at the first end 310. The second sensor array 200 may have a size a4×b4, a4 > A1, and B4 > B1, and a1=12x, b1=12y, a4=16x, and b4=16y in the case where the crystal array 300 is a 12×12 array, each of the scintillator crystals 330 is x×y in size, and the second sensor array 200 is a4×4 array, and the second photosensor 210 is a4×4Y in size, so that the second sensor array 200 may have a coverage area 230 covering the crystal array 300 and an excess area 220 exceeding the crystal array 300. The footprint 230 may have the same size and shape as the second end 320 of the crystal array 300 and the overrunning zone 220 may have various shapes and sizes. The coverage area 230 and the over-coverage area 220 are only partitions made on the second sensor array 200 for convenience of description, and the second photosensors 210 located in the over-coverage area 220 and the coverage area 230 are not particularly limited in terms of the locations, and the plurality of second photosensors 210 may be the same photosensors or different photosensors whether located in the over-coverage area 220 or the coverage area 230. The design of the overrun zone 220 ensures that the second sensor array 200 has completely covered the second end 320 of the crystal array 300, thereby ensuring that each scintillation crystal 330 can perform a double ended calculation of DOI with the first sensor array 100 also covering the first end 310 of the crystal array 300, thus improving the accuracy of the detector 10 in calculating DOI.

Further, the scintillation crystal 330 can be sized X Y, the crystal array 300 can have a first direction (i.e., the X-X direction as shown) and a second direction (i.e., the Y-Y direction as shown) perpendicular to each other, the outer edge of the excess zone 220 can be 2X from the outer edge of the footprint 230 in the first direction, and the outer edge of the excess zone 220 can be 2Y from the outer edge of the footprint 230 in the second direction. Specifically, the scintillation crystals 330 are arranged in a plurality of rows and columns, the crystal array 300 is arranged in a square shape, the second sensor array 200 is coupled to the second end 320 of the crystal array 300, and the excess zone 220 and the footprint 230 are spaced apart by two rows or columns of scintillation crystals 330 in both the X-X direction and the Y-Y direction. Such a detector 10 is more regular, and the plurality of second photosensors 210 have the same shape and size, and is simple in structure and convenient in production.

Referring to fig. 2, 7 and 8 in combination, the second sensor array 200 may have a size of a5×b5, a5 < A1, B5 > B1, and in the case that the crystal array 300 is a 12×12 array, each scintillation crystal 330 has a size of x×y, the second sensor array 200 is a 2×4 array, and the second photosensor 210 has a size of 4x×4Y, a1=12x, b1=12y, a5=8x, b5=16y, such that the crystal array 300 may have at least a middle region 340 covered by the second sensor array 200 and a peripheral region 350 uncovered by the second sensor array 200 at the second end 320, the sides may include a third side 333 between the middle region 340 and the peripheral region 350, and the third side 333 may be provided with a third light-transmitting window 336 at a position remote from the second end 320. When the detection range of the detector 10 needs to be enlarged, only a plurality of second photoelectric sensors 210 need to be connected in a supplementing way, so that more scintillation crystals 330 for realizing the window method and the double-end method DOI calculation can be realized, and the third light-transmitting window 336 can play the same role as the second light-transmitting window 335, so that the detection range of the detector 10 is enlarged.

Referring again to fig. 2, 7, and 8 in combination, the scintillation crystal 330 has dimensions X Y, the crystal array 300 can have a first direction and a second direction perpendicular to each other, and the outer edge of the peripheral region 350 can be 2X from the outer edge of the middle region 340 in the first direction; and the second sensor array 200 may have an excess region 220 that is outside the crystal array 300 in the second direction, and the outer edge of the excess region 220 may be 2Y from the outer edge of the middle region 340 in the second direction. Specifically, the scintillation crystals 330 are arranged in a plurality of rows and columns, the crystal array 300 is arranged in a square shape, and two columns of scintillation crystals 330 are spaced between the outer edge of the peripheral region 350 and the outer edge of the middle region 340; two rows of scintillation crystals 330 are spaced from the outer edge of the outer region 220 and the outer edge of the middle region 340. Such a detector 10 having more scintillation crystals 330 in the second direction (i.e., the Y-Y direction as shown) allows for window and double-ended DOI calculations, thereby enhancing the detection of the detector 10. And such a detector 10 may be adapted to the needs of some practical situations. In the illustrated embodiment, the second sensor array 200 has an excess region 220 in the second direction that is outside the crystal array 300 and the crystal array 300 has a surrounding region 350 in the first direction that is not coupled to the second photosensor 210, but it should be noted that in other embodiments, the second sensor array 200 may have an excess region 220 in the first direction that is outside the crystal array 300 and the crystal array 300 may have a surrounding region 350 in the second direction that is not coupled to the second photosensor 210, and those skilled in the art may design a specific arrangement of the relative positions of the second sensor array 200 and the crystal array 300 according to the actual situation.

In several embodiments of the present invention, the first photosensor 110 is offset from the second photosensor 210. When the first photoelectric sensor 110 and the second photoelectric sensor 210 are arranged in a staggered manner, it can be ensured that at most one light-transmitting window is formed on one side, for example, at most one first light-transmitting window 334 is formed on one first side 331. The design can avoid that a plurality of light-transmitting windows are arranged on the same side face, and the plurality of light-transmitting windows can interfere with each other when being used for calculating DOI by a window method. Thus, such a detector 10 is more convenient to use and has a good detection effect.

In several of the embodiments presented above, the crystal array 300 may have a first direction (i.e., the illustrated X-X direction) and a second direction (i.e., the illustrated Y-Y direction) that are perpendicular to each other, and the first photosensor 110 may be offset from the second photosensor 210 by two of the scintillation crystals 330 in the first direction and/or the second direction. Specifically, the scintillation crystals 330 are arranged in a plurality of rows and columns, the crystal array 300 is arranged in a square shape, and the first photosensor 110 and the second photosensor 210 are spaced apart by two rows or two columns of the scintillation crystals 330 in the X-X direction and the Y-Y direction. This can achieve a dimension ratio of the first photosensor 110 and the second photosensor 210 relative to the scintillator crystal 330 of 1 in both the first direction and the second direction: 4, the ratio of the scintillation crystal 330 for calculating the DOI by the window method and the double-end method in all the scintillation crystals 330 is larger, so that the detection effect of the detector 10 is better.

It should be noted that, although in the above embodiments, the first sensor array 100 and the second sensor array 200 are arranged in a staggered manner, in the embodiment not shown, the first sensor array 100 and the second sensor array 200 may be arranged in a non-staggered manner. In this case, there is a case where two light-transmitting windows may be provided on one side of one scintillation crystal 330, for example, the first photosensor 110 and the second photosensor 210 are coupled to both ends of one scintillation crystal 330, and the scintillation crystal 330 is located at the edges of the first photosensor 110 and the second photosensor 210 at the same time, that is, the first side 331 located between the adjacent two first photosensors 110 and the second side 332 located between the adjacent two second photosensors 210 on the scintillation crystal 330 are the same side. At this time, the first side 331 is provided with a first light-transmitting window 334 at a position far from the first end 310, and the second side 332 is provided with a second light-transmitting window 335 at a position far from the second end 320, that is, on the same side, the first light-transmitting window 334 and the second light-transmitting window 335 are simultaneously provided. Such a scintillation crystal 330 can also implement both window and double ended calculations of DOI.

In the description of the present invention, it should be understood that the azimuth or positional relationships indicated by the azimuth terms such as "front", "rear", "upper", "lower", "left", "right", "transverse", "vertical", "horizontal", and "top", "bottom", etc., are generally based on the azimuth or positional relationships shown in the drawings, merely for convenience of describing the present invention and simplifying the description, and these azimuth terms do not indicate and imply that the apparatus or elements referred to must have a specific azimuth or be constructed and operated in a specific azimuth, without limiting the scope of protection of the present invention; the orientation terms "inner" and "outer" refer to the inner and outer relative to the outline of the components themselves.

For ease of description, regional relative terms, such as "above … …," "above … …," "upper surface at … …," "above," and the like, may be used herein to describe regional positional relationships of one or more components or features to other components or features illustrated in the figures. It will be understood that the relative terms of regions include not only the orientation of the components illustrated in the figures, but also different orientations in use or operation. For example, if the element in the figures is turned over entirely, elements "over" or "on" other elements or features would then be included in cases where the element is "under" or "beneath" the other elements or features. Thus, the exemplary term "above … …" may include both orientations of "above … …" and "below … …". Moreover, these components or features may also be positioned at other different angles (e.g., rotated 90 degrees or other angles), and all such cases are intended to be encompassed herein.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, components, assemblies, and/or combinations thereof.

It should be noted that the terms "first," "second," and the like in the description and claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that embodiments of the present application described herein may be implemented in sequences other than those illustrated or described herein.

The present invention has been illustrated by the above-described embodiments, but it should be understood that the above-described embodiments are for purposes of illustration and description only and are not intended to limit the invention to the embodiments described. In addition, it will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that many variations and modifications are possible in light of the teachings of the invention, which variations and modifications are within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A detector, comprising:

a plurality of scintillation crystals, a plurality of the scintillation crystals forming a crystal array, the crystal array having a first end and a second end, the scintillation crystals having sides between the first end and the second end;

a plurality of first photosensors forming a first sensor array coupled to the first end; and

a plurality of second photosensors forming a second sensor array, the second sensor array coupled to the second end;

the side surfaces comprise a first side surface positioned between two adjacent first photoelectric sensors and a second side surface positioned between two adjacent second photoelectric sensors, wherein the first side surface is provided with a first light-transmitting window at a position far away from the first end, and the second side surface is provided with a second light-transmitting window at a position far away from the second end.

2. The detector of claim 1, wherein the scintillation crystal is X Y in size and the first photosensor is 4X 4Y in size.

3. The detector of claim 2, wherein the second photosensor is 4X 4Y in size.

4. The detector of claim 1, wherein the crystal array has a size a1×b1 and the first sensor array has a size a2×b2, a2=a1, b2=b1 such that the crystal array is completely covered by the first sensor array at the first end.

5. The detector of claim 4, wherein the second sensor array has a size a3×b3, a3 < A1, B3 < B1 such that the crystal array is divided at the second end into a middle region covered by the second sensor array and a peripheral region uncovered by the second sensor array, the sides including a third side between the middle region and the peripheral region, the third side being provided with a third light transmissive window at a location remote from the second end.

6. The detector of claim 5, wherein the scintillation crystal has a size X Y, the crystal array has a first direction and a second direction perpendicular to each other, the outer edge of the peripheral region is 2X from the outer edge of the central region in the first direction, and the outer edge of the peripheral region is 2Y from the outer edge of the central region in the second direction.

7. The detector of claim 4, wherein the second sensor array has a size a4×b4, a4 > A1, B4 > B1 such that the second sensor array has a footprint that covers the crystal array and an overrun zone that extends beyond the crystal array.

8. The detector of claim 7, wherein the scintillation crystal has dimensions X Y, the crystal array has a first direction and a second direction perpendicular to each other, the outer edge of the over-zone is 2X from the outer edge of the coverage area in the first direction, and the outer edge of the over-zone is 2Y from the outer edge of the coverage area in the second direction.

9. The detector of claim 4, wherein the second sensor array has a size a5×b5, A5 < A1, B5 > B1 such that the crystal array has at least a central region covered by the second sensor array and a peripheral region uncovered by the second sensor array at the second end, the sides including a third side between the central region and the peripheral region, the third side being provided with a third light transmissive window at a location remote from the second end.

10. The detector of claim 9, wherein the scintillation crystal has a size X Y, the crystal array has a first direction and a second direction perpendicular to each other, and the outer edge of the peripheral region is 2X from the outer edge of the central region in the first direction; and the second sensor array has an excess region in the second direction that is outside the crystal array, the distance of the outer edge of the excess region from the outer edge of the middle region in the second direction being 2Y.

11. A detector according to claim 3, wherein the first and second photosensors are arranged offset.

12. The detector of claim 11, wherein the crystal array has a first direction and a second direction perpendicular to each other, the first photosensor being offset from the second photosensor by two of the scintillation crystals in the first direction and/or the second direction.

13. An emission imaging device comprising a processor module and the detector of any of claims 1-12, a plurality of the first photosensors and a plurality of the second photosensors each electrically connected to the processor module.