Spatially coded detector, spatial coding, decoding method, apparatus and storage medium

Abstract

This application proposes a spatial coding detector, spatial coding, decoding method, apparatus, and storage medium. The spatial coding detector includes a scintillation crystal array and a photoelectric converter. The scintillation crystal array includes at least two crystal strips, wherein the at least two crystal strips have different decay times. The photoelectric converter is coupled to the crystal array. The spatial coding method includes: establishing a spatial position coding table for the scintillation crystal array; selecting crystal strips of corresponding specifications from the spatial position coding table to form the scintillation crystal array according to spatial resolution requirements; and coupling the scintillation crystal array and the photoelectric converter according to a preset coding order or preset coding position. By spatially coding the crystal strips in the scintillation crystal array, this application can decode additional spatial information through decay time, thereby overcoming the limitation of photoelectric converter arrays on detector spatial resolution.

Description

Technical Field

[0001] This application relates to the field of radiation detection, and more specifically, to a spatial coding detector, spatial coding, decoding method, apparatus, and storage medium. Background Technology

[0002] X-rays generally refer to photon beams with energies of at least 100 eV, including X-rays, gamma rays, alpha rays, beta rays, neutron rays, and proton rays. The ability of a radiation detector to resolve energy, temporal, and spatial information directly determines the imaging quality of the detection system. For example... Figure 1 As shown, the working principle of the X-ray detector is as follows: First, the X-ray interacts with the scintillation crystal, converting the X-ray into visible light photons. These visible light photons are transported within the scintillation crystal and incident on a photoelectric conversion device coupled to it. The photoelectric conversion device converts the incident visible light into an electrical signal, which is then acquired and output as a digital signal by an electronics system matched to the photoelectric conversion device. Finally, using software algorithms, information such as the time, energy, and position of the X-ray can be calculated from the digital signal.

[0003] Gamma ray detection has a wide range of applications. For example, positron emission tomography (PET) uses gamma ray detectors as the front end of the system to obtain information on the distribution of positron annihilation events, thereby assisting in cancer diagnosis and treatment, brain science research, cardiology research, heavy ion radiotherapy monitoring, and so on.

[0004] Based on the time performance requirements of PET, the X-ray detectors currently in use are basically based on scintillation crystals and photoelectric conversion devices. Typical scintillation crystals include LYSO, BGO, and YSO, while photoelectric conversion devices include position-sensitive PMT, SiPM, and SPAD.

[0005] Currently, common crystal detectors include single-layer array single decay time scintillation crystal array detectors, single-layer array scintillation crystal + photoconductor layer detectors, dual-end readout single-layer single decay time scintillation crystal detectors, and combined scintillation crystal array detectors.

[0006] A single-layer array scintillation crystal detector consists of multiple crystal strips with the same decay time arranged into a scintillation crystal array. Reflective materials, such as barium sulfate coatings or process reflective films, are used to establish complete optical isolation between the crystal strips and between the crystal strips and the external environment. The optical surface at one end of the crystal strip is not covered with reflective material and is coupled to the photoelectric conversion device array via a coupling agent such as silicone grease.

[0007] A single-layer array scintillation crystal and photoconductor detector adds a transparent medium, i.e., a photoconductor, between the scintillation crystal array and the photoelectric conversion device array. Visible light photons, after exiting the scintillation crystal, undergo a divergence process before entering the photoelectric conversion device array.

[0008] The dual-end readout single-layer single-decay time scintillation crystal detector does not cover the optical surfaces at both ends of the crystal strip with reflective material, and is coupled to the photoelectric converter array through optical coupling agents such as silicone grease.

[0009] A combined scintillation crystal detector is a combination of a multi-layer scintillation crystal array and a multi-layer continuous scintillation crystal array, which are then coupled to an array of photoelectric conversion devices.

[0010] For single-layer crystal arrays, the spatial resolution on the projection plane is limited by the size of the photoelectric conversion device. Combined scintillation crystal detectors, on the other hand, suffer from problems such as complex structure, high manufacturing difficulty, and high bit error rate. Summary of the Invention

[0011] This application proposes a spatial coding detector, spatial coding and decoding method, apparatus, electronic device and storage medium to solve the problem of spatial resolution limitation caused by the size of photoelectric conversion device in the detector.

[0012] According to one aspect of this application, a spatial coding detector is proposed, comprising: a scintillation crystal array and a photoelectric converter, wherein the scintillation crystal array comprises at least two crystal strips, wherein the at least two crystal strips have different decay times; and the photoelectric converter is coupled to the crystal array.

[0013] According to some embodiments, the scintillation crystal array includes at least one crystal unit, and the crystal unit includes a plurality of the crystal strips.

[0014] According to some embodiments, at least two crystal bars in the crystal unit have different decay times, or the decay time of at least some of the crystal bars in the crystal unit is different from the decay time of at least one crystal bar.

[0015] According to some embodiments, the at least one crystal unit is the same size, and the decay time of at least a portion of the crystal strips differs between different crystal units.

[0016] According to some embodiments, the scintillation crystal array includes at least two sizes of crystal units, and at least a portion of the crystal strips have different decay times between different crystal units.

[0017] According to some embodiments, the crystal bars in the crystal unit are arranged in a matrix, and the crystal bars at corresponding positions in different crystal units have the same decay time.

[0018] According to some embodiments, the decay time of each of the crystal strips is different.

[0019] According to some embodiments, the decay time of the crystal strips follows an arithmetic progression.

[0020] According to some embodiments, the decay time of the crystal strip is between 30 ns and 50 ns.

[0021] According to some embodiments, some of the crystal strips have different external dimensions.

[0022] According to some embodiments, the crystal strip has a shape including prisms, cylinders, or irregular shapes.

[0023] According to some embodiments, the photoelectric converter is a photoelectric conversion device array, and each unit in the photoelectric conversion device array is coupled to the crystal bar in a one-to-one, one-to-many, or many-to-one manner.

[0024] According to one aspect of this application, a spatial coding method is proposed, the spatial coding method comprising: establishing a spatial position coding table for a scintillation crystal array, the spatial position coding table including the correspondence between crystal bars of different decay times and different sizes and spatial resolution; selecting crystal bars of corresponding specifications from the spatial position coding table to form the scintillation crystal array according to spatial resolution requirements; and coupling the scintillation crystal array with a photoelectric converter according to a preset coding order or preset coding position.

[0025] According to some embodiments, the spatial location encoding table also includes the correspondence between the spatial resolution and the crystal bars of different positions, sizes or decay times arranged in a preset encoding order or preset encoding position.

[0026] According to some embodiments, the same spatial resolution corresponds to multiple forms of the preset encoding order or the preset encoding position.

[0027] According to some embodiments, the photoelectric converter is a photoelectric conversion device array, and each unit in the photoelectric conversion device array is coupled to the crystal strip in a one-to-one, one-to-many, or many-to-one manner.

[0028] According to one aspect of this application, a spatial decoding method is proposed for use in a spatially encoded detector as described above. The spatial decoding method includes: acquiring information about the ray using a pulse signal output by a photoelectric converter, the information including energy information, arrival time, and decay time; determining the crystal unit where the ray is deposited using the energy information and the arrival time; and acquiring the deposition location of the ray using the decay time and a pre-established lookup table, the lookup table including a correspondence between the decay time and the ray deposition location.

[0029] According to some embodiments, acquiring information about the ray using the pulse signal output by the photoelectric converter includes: acquiring information about the ray using a multi-voltage threshold sampling method, an oscilloscope, or an analog-to-digital converter.

[0030] According to some embodiments, determining the crystal unit for X-ray deposition includes: determining the crystal unit for X-ray deposition using a one-to-one coupling method or a centroid method based on the coupling form between the scintillation crystal array and the photoelectric converter.

[0031] According to some embodiments, the lookup table is pre-established by: probing the rays using crystal strips of different specifications; calculating the decay time of the rays deposited in each crystal strip; and establishing the lookup table using the calculated decay time and the deposition position of the rays in different crystal strips.

[0032] According to one aspect of this application, a spatial decoding device is proposed for use with the spatial coding detector described above. The spatial decoding device includes: a ray information acquisition unit for acquiring ray information using a pulse signal output by a photoelectric converter, the information including energy information, arrival time, and decay time; a crystal region determination unit for determining the crystal unit where the ray is deposited using the energy information and the arrival time; and a deposition location determination unit for obtaining the deposition location of the ray using the decay time and a pre-established lookup table, the lookup table including the correspondence between the decay time and the deposition location.

[0033] According to one aspect of this application, a spatial decoding apparatus is provided, comprising: one or more processors; a storage device for storing a computer program; and, when the computer program is executed by the one or more processors, causing the one or more processors to implement the method described above.

[0034] According to one aspect of this application, a storage medium is provided that stores program instructions thereon, which, when executed, implement the method described above.

[0035] When calculating the deposition location of rays, the spatial resolution of the photoelectric conversion device array limits the detector's ability to distinguish the deposition location. This application addresses this by spatially encoding the decay time of the crystal strips in the scintillation crystal array and further locating the specific crystal strip where deposition occurs using the additional spatial information decoded from the decay time. This overcomes the limitation of the spatial resolution of the photoelectric conversion device array on the spatial resolution of the detector. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0037] Figure 1 A schematic diagram illustrating the working principle of an X-ray detector is shown.

[0038] Figure 2a This is a side view of a spatial coding detector according to an example embodiment of the present application.

[0039] Figure 2b A cross-sectional view of a spatial coding detector according to an example embodiment of this application is shown.

[0040] Figure 3 This diagram illustrates the spatial coding of a scintillation crystal array according to an example embodiment of this application.

[0041] Figure 4 A schematic diagram of the spatial coding of another scintillation crystal array according to an example embodiment of this application is shown.

[0042] Figure 5 A flowchart illustrating a spatial encoding method according to an example embodiment of this application is shown.

[0043] Figure 6 A flowchart illustrating a spatial decoding method according to an example embodiment of this application is shown.

[0044] Figure 7 A flowchart illustrating a method for creating a lookup table according to an example embodiment of this application is shown.

[0045] Figure 8 A schematic block diagram of a spatial decoding apparatus according to an example embodiment of this application is shown.

[0046] Figure 9 Another spatial decoding apparatus according to an embodiment of this application is shown. Detailed Implementation

[0047] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this application will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted.

[0048] The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced without one or more of these specific details, or other methods, components, materials, apparatus, or operations may be employed. In these cases, well-known structures, methods, apparatuses, implementations, materials, or operations will not be shown or described in detail.

[0049] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0050] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0051] The specific embodiments according to this application will now be described in detail with reference to the accompanying drawings.

[0052] Figure 2a A side view of a spatial coding detector according to an example embodiment of this application is shown. Figure 2b A schematic cross-sectional view of a spatial coding detector according to an example embodiment of this application is shown.

[0053] like Figure 2a and Figure 2bThe spatial coding detector shown includes a scintillation crystal array 10 and a photoelectric conversion device array 20 coupled to the scintillation crystal array 10. The scintillation crystal array 10 includes crystal bars 11 arranged in m rows and n columns, and the photoelectric conversion device array 20 includes photoelectric conversion devices arranged in c rows and d columns. M, n, c, and d are all integers greater than or equal to 1, and m, n, c, and d are not all 1 at the same time.

[0054] According to some embodiments of this application, the multiple crystal strips 11 in the scintillation crystal array 10 can be combined in different arrangements to form the scintillation crystal array 10. Those skilled in the art should note that... Figures 2a-4 In the example embodiment, the crystal strip 11 is in the shape of a cuboid, and the scintillation crystal array 10 is a cuboid formed by closely arranging the crystal strips 11. However, in this application, the crystal strip 11 can also be a prism shape, a cylinder shape, or other irregular shape with different numbers of edges. The scintillation crystal array 10 can also be formed by combining and arranging these crystal strips 11 of different shapes to form various shapes, such as cubes, single rows, irregular shapes, etc.

[0055] Those skilled in the art should also note that in the above embodiments, the crystal strips 11 are arranged according to the row and column directions of a matrix, but they can also be arranged in an irregular manner. For example: in the first case, cuboid crystal strips of the same specification are arranged irregularly, such as crystal strips of the same shape and specification being arranged alternately in the row or column direction, with the same crystal strip corresponding to two crystal strips in an adjacent row or column; in the second case, cuboid crystal strips of different shapes and specifications are arranged irregularly, such as crystal strips of two different sizes being arranged alternately in the row or column direction, with the larger crystal strip corresponding to multiple smaller crystal strips in an adjacent row or column; in the third case, the crystal strips are not completely identical in shape and specification, and their arrangement is not entirely regular, such as some crystal strips being prism-shaped and others being cylindrical, with crystal strips of various specifications being arranged alternately. These arrangements and shapes, through corresponding spatial encoding, can also obtain corresponding spatial distribution information on the projection plane, which will not be elaborated further here.

[0056] According to some embodiments of this application, in the scintillation crystal array 10, at least two crystal strips 11 have different decay times. Preferably, each crystal strip 11 in the scintillation crystal array 10 has a different decay time. According to some embodiments, the decay times of multiple crystal strips 11 in the same scintillation crystal array 10 form an arithmetic sequence. For example, the scintillation crystal 10 includes m×n crystal strips 11, and the decay times of these crystal strips 11 are all between 30ns and 50ns and form an arithmetic sequence. By utilizing the different decay times of the crystal strips, the crystal strips are arranged according to a specific pattern, thereby encoding the spatial information of the crystal strips into the decay time of the scintillation crystal array.

[0057] In the embodiments of this application, visible light is generated by the interaction of high-energy rays with the scintillation crystal. The generation rate of visible light photons reaches its maximum value within a very short period of time, and then decreases to 0 according to an exponential model. Therefore, the decay time is usually defined as the time required for the visible light generation rate to decrease to 1 / e (where e is the natural base) of the maximum generation rate. The decay time is an inherent property of the scintillation crystal, determined by the type of crystal and the manufacturing process. Scintillation crystals with specific decay times can be produced as needed within a certain range, which will not be elaborated further here.

[0058] Those skilled in the art should note that the definition of decay time can vary for different high-energy rays. They can define different decay times as needed. For example, the decay time can be defined as the time required for the visible light generation rate to decrease to 2 / e of the highest point generation rate. This can be achieved simply by ensuring that at least some crystal bars in the scintillation crystal array 10 have different decay times, thereby allowing photons to be incident on the photoelectric conversion device array in different times. This is something that those skilled in the art can easily conceive of based on the teachings of this application, and will not be elaborated further here.

[0059] When calculating the deposition location of rays, the spatial resolution of the photoelectric conversion device array coupled with the scintillation crystal array limits the ability to resolve the region corresponding to the deposition of high-energy rays. However, by setting multiple crystal strips with different decay times in the scintillation crystal array, the different decay time information corresponding to different regions is encoded with the crystal strips, and additional spatial information is decoded by the decay time. This allows for the location of the specific crystal strip in the scintillation crystal array where deposition occurs, thereby overcoming the limitation of the photoelectric conversion device array resolution on the detector's spatial resolution.

[0060] Figure 2a and Figure 2bThe illustrated embodiments can be used in detectors that include scintillation crystal arrays, such as detectors that include a single-layer scintillation crystal array or detectors that include a multi-layer scintillation crystal array. By using crystal bars with different decay times in the scintillation crystal array and decoding the decay time of the rays, it is possible to overcome the limitation of the photoelectric conversion device array resolution on the detector spatial resolution in single-layer array spatial coding detectors, and also to solve the problem of high bit error rate in multi-layer or combined scintillation crystal detectors.

[0061] Furthermore, according to some embodiments of this application, the crystal strips 11 in the scintillation crystal array 10 can be divided into multiple crystal units, each crystal unit including multiple crystal strips 11, and at least a portion of the crystal strips in each crystal unit have different decay times, or different crystal units have different decay times. According to some embodiments, the decay times of multiple crystal strips in the same crystal unit can form an arithmetic sequence. By utilizing the different decay times of the scintillation crystals, the crystal strips are arranged according to a specific pattern, thereby encoding the spatial information of the crystal strips into the decay time of the scintillation crystal array.

[0062] According to some embodiments, the size of multiple crystal units can be the same or different, and the number of crystal bars, external dimensions, and decay time in different crystal units can also not be exactly the same.

[0063] According to some embodiments, when the scintillation crystal array is in the form of a cuboid matrix, the crystal units can be divided according to the arrangement order of the rows or columns of the scintillation crystal array, and the size of each crystal unit can be the same or different.

[0064] According to some embodiments, crystal units can be divided according to the arrangement order of the outer and inner rings of the scintillation crystal array. The decay time of each crystal strip in different crystal units can be exactly the same, not exactly the same, or completely different. At least some crystal strips in different crystal units have different decay times.

[0065] Figure 3 This diagram illustrates a scintillation crystal array block diagram according to an example embodiment of this application. Figure 3 In one embodiment, the scintillation crystal array is divided into multiple crystal units of the same size 1, 2, 3, ..., s according to the row and column order of the crystal bars, where s is a natural number. Figure 3 In this embodiment, the scintillation crystal array 10 is divided into s crystal units of the same size, and each crystal unit contains 4 crystal strips of the same size. The specific numbering of the crystal strips can be as follows: Figure 2b As shown in the image.

[0066] According to some embodiments, the crystal bars in the same crystal unit have the same decay time, while the crystal bars in different crystal units have different decay times.

[0067] For example, the decay times of crystal strips 1-1, 2-1, 1-2, and 2-2 in crystal unit 1 are the same, all being 30 ns. The decay times of crystal strips 3-1, 4-1, 3-2, and 4-2 in crystal unit 2 are the same, all being 30.5 ns, and so on.

[0068] According to some embodiments, at least some crystal bars in the same crystal unit have different decay times than other crystal bars, and the decay times of crystal bars in different crystal units are not exactly the same.

[0069] For example, in crystal unit 1, crystal strips 1-1 and 2-2 have the same decay time of 30 ns, and crystal strips 2-1 and 1-2 have the same decay time of 31 ns; in crystal unit 2, crystal strips 3-1 and 4-2 have the same decay time of 30.5 ns, and crystal strips 4-1 and 3-2 have the same decay time of 31 ns, and so on.

[0070] According to some embodiments, the crystal bars in the same crystal unit have different decay times.

[0071] For example, the decay times of crystal strips 1-1, 2-1, 1-2, and 2-2 in crystal unit 1 are different from each other. The decay time settings of each crystal strip in crystal unit 2, crystal unit 3, crystal unit 4, ... crystal unit s are the same as those in crystal unit 1.

[0072] According to some embodiments, the decay times of the crystal strips in the same crystal unit follow an arithmetic progression.

[0073] According to some embodiments, the decay times of the crystal bars in the same crystal unit are an arithmetic sequence with a tolerance range of 30 to 50 ns.

[0074] According to some example embodiments of this application, crystal bars at the same position in different crystal units have the same decay time, while crystal bars at different positions in the same crystal unit have not the same decay time.

[0075] For example, the decay time of crystal strip 1-1 is the same as that of crystal strip 3-1, crystal strip 1-3, and crystal strip 3-3; the decay time of crystal strip 2-1 is the same as that of crystal strip 4-1, crystal strip 2-3, and crystal strip 4-3; the decay time of crystal strip 1-2 is the same as that of crystal strip 3-2, crystal strip 1-4, and crystal strip 3-4; and the decay time of crystal strip 2-2 is the same as that of crystal strip 4-2, crystal strip 2-4, and crystal strip 4-4. However, the decay times of crystal strips 1-1, 1-2, 2-1, and 2-2 are not exactly the same.

[0076] according to Figure 3The embodiment shown divides the scintillation crystal array into multiple crystal units of the same size, with at least some crystal units having different decay times. This allows for the additional spatial information decoded by the decay time to further locate the specific crystal stripe deposited in the crystal unit when calculating the deposition location of the ray, thereby overcoming the limitation of the spatial resolution of the photoelectric conversion device array on the spatial resolution of the detector.

[0077] Figure 4 This diagram illustrates another scintillation crystal array segmentation according to an example embodiment of this application. Figure 4 In one embodiment, the scintillation crystal array is divided into multiple crystal blocks of slightly different sizes according to the row and column order of the crystal bars, such as... Figure 4 As shown, thicker lines represent the same crystal unit, while thinner lines represent crystal bars within the same crystal unit. Figure 4 The scintillation crystal array includes multiple crystal units 30, 40, and 50 of different sizes. Crystal unit 30 includes 4×4 crystal strips 11, crystal unit 40 includes 4×2 crystal strips 11, and crystal unit 50 includes 2×2 crystal strips 11.

[0078] exist Figure 4 In the embodiments, the decay time settings of the crystal bars in the same crystal unit and the decay time settings of the crystal bars in different crystal units can be consistent with... Figure 3 The same applies to the embodiments, and will not be repeated here.

[0079] according to Figure 4 The embodiment shown divides the scintillation crystal array into multiple crystal units of different sizes, and at least some of the crystal units have different decay times. This allows for the additional spatial information decoded by the decay time to further locate the specific crystal strips deposited in different crystal units when calculating the deposition location of the rays. This overcomes the limitation of the spatial resolution of the photoelectric conversion device array on the spatial resolution of the detector.

[0080] Figure 5 A flowchart of a spatial encoding method according to an example embodiment of this application is shown. Figure 5 The spatial encoding method shown is used to include, for example, Figures 2a-4 The scintillation crystal array detector shown.

[0081] In step S501, a spatial position encoding table for the scintillation crystal array is established. The spatial position encoding table contains the correspondence between the decay time and size of the crystal strips and the spatial resolution of the detector.

[0082] According to some embodiments of this application, the spatial location coding table may also include the correspondence between the spatial resolution of the detector and the crystal bars with different positions, sizes, and decay times arranged in a preset coding order and coding position.

[0083] According to some embodiments of this application, the preset encoding order, encoding position, size, and attenuation time settings of the crystal bar can be configured with... Figures 2a-4 The embodiments are the same as those in the previous examples, and will not be repeated here.

[0084] In step S503, crystal bars of the corresponding specifications are selected from the spatial coding table in step S501 according to different spatial resolution requirements in actual applications, and arranged according to the preset coding order or coding position.

[0085] According to some embodiments, the same spatial resolution can correspond to multiple forms of encoding order or encoding position.

[0086] In step S505, the crystal strips are assembled according to the preset encoding order or encoding position to obtain a spatially encoded detector with the corresponding spatial resolution.

[0087] According to some embodiments, the assembled scintillation crystal array is coupled to the photoconverter in a one-to-one manner. Visible light photons generated after radiation is deposited within the crystal strips enter only one corresponding photoconverter.

[0088] According to some embodiments, the assembled scintillation crystal array is coupled to the photoelectric converter in a one-to-many manner. Visible light photons generated after rays are deposited within the crystal strips can enter the corresponding multiple photoelectric conversion devices.

[0089] According to some embodiments, the assembled scintillation crystal array is coupled to the photoelectric converter in a many-to-one manner. Visible light photons generated within multiple crystal strips enter the same photoelectric conversion device. According to some example embodiments of this application, the location of ray deposition in the many-to-one coupled spatially encoded detector is determined using the centroid method. For example, the center coordinates of each photoelectric conversion device and the weighted average coordinates of the detected photon count are first calculated, and the specific location of the ray deposition is determined by comparing the weighted average coordinates with the center coordinates.

[0090] according to Figure 5 The embodiment shown uses a spatial location coding table to design the detector, so that at least some crystal strips have different decay times. This allows for more precise positioning of the specific crystal strips where deposition occurs by decoding additional spatial information from the decay time when detecting rays, thereby overcoming the limitation of the spatial resolution of the photoelectric conversion device array on the spatial resolution of the detector.

[0091] Figure 6A flowchart of a spatial decoding method according to an example embodiment of this application is shown. Figure 5 The spatial decoding method shown is used to include, for example, Figures 2a-4 The spatial coding detector shown.

[0092] like Figure 6 As shown, in step S601, the pulse signal output by the photoelectric converter or photoelectric converter array is used to obtain the information of the ray, wherein the information of the ray includes energy, arrival time and decay time.

[0093] According to some embodiments of this application, the pulse signal output by the photoelectric converter is sampled using a multi-voltage threshold (MVT) sampling method, an oscilloscope, or an analog-to-digital converter to obtain information about the ray, such as the energy information, arrival time, and decay time of the ray.

[0094] In step S603, the crystal unit for X-ray deposition is determined using the X-ray energy information and arrival time obtained in step S601.

[0095] According to some embodiments, the scintillation crystal array in the spatially coded detector is coupled to the photoelectric converter in a one-to-one manner. Visible light photons generated after X-ray deposition on the scintillation crystal array enter only one photoelectric conversion device. According to some example embodiments of this application, the block of X-ray deposition in the one-to-one coupled spatially coded detector is determined using a one-to-one coupling method.

[0096] According to some embodiments, the assembled scintillation crystal array is coupled to the photoelectric converter in a one-to-many manner. Visible light photons generated after rays are deposited within the crystal strips can enter the corresponding multiple photoelectric conversion devices.

[0097] According to some embodiments, the scintillation crystal array in the spatially coded detector is coupled to the photoelectric converter in a many-to-one manner. Visible light photons generated within multiple crystal strips enter the same photoelectric converter. According to some example embodiments of this application, the ray deposition block in the many-to-one coupled spatially coded detector is determined using the centroid method. For example, the center coordinates of each photoelectric converter and the weighted average coordinates of the detected photon count are first calculated, and the ray deposition block is determined by comparing the weighted average coordinates with the center coordinates.

[0098] In step S605, the deposition location of the ray is obtained using the attenuation time of the ray and a pre-established lookup table. The lookup table includes the correspondence between attenuation time and deposition location.

[0099] According to some embodiments of this application, a lookup table needs to be pre-established before step S605. The lookup table includes the correspondence between the attenuation time of the rays and the deposition location. The lookup table is established as follows: Figure 7 As shown. After determining the crystal unit for X-ray deposition through step S603, the specific crystal strip for X-ray deposition can be determined using the decay time obtained in step S601 and the pre-established lookup table.

[0100] according to Figure 6 The embodiment shown first determines the crystal unit for X-ray deposition, and then uses the coding information of each crystal strip to further locate the specific crystal strip in the determined deposition crystal unit where deposition occurs, thus overcoming the limitation of the resolution of the photoelectric conversion device on the spatial resolution of the detector.

[0101] Figure 7 A flowchart illustrating a method for creating a lookup table according to an example embodiment of this application is shown.

[0102] like Figure 7 As shown, in step S701, crystal strips of different specifications are used to detect rays.

[0103] According to some embodiments, different specifications include different crystal strip sizes, different decay times, or different materials coated on the outside of the crystal strip. When X-rays are deposited in crystal strips of different specifications, the parameter information of the pulses collected by the detector varies, including pulse arrival time, energy, and other information.

[0104] In step S703, the decay time of the rays deposited in each crystal strip is calculated.

[0105] According to some embodiments, the pulse signal output by the photoelectric converter is sampled using a multi-voltage threshold sampling method, an oscilloscope, or an analog-to-digital converter to calculate the decay time of the rays deposited in each crystal strip.

[0106] In step S705, a lookup table is created using the calculated decay time and the deposition location of the ray in the crystal strip.

[0107] according to Figure 7 The example shown establishes a lookup table that includes the correspondence between the decay time of the X-ray and the position of the crystal strips deposited by the X-ray.

[0108] Figure 8 This diagram illustrates a spatial decoding apparatus according to an example embodiment of the present application. According to some embodiments, Figure 8 The device shown is used for, for example Figures 2a-4 The spatial coding detector shown.

[0109] like Figure 8The spatial decoding device shown includes a ray information acquisition unit 801, a crystal region determination unit 803, and a deposition location determination unit 805. The ray information acquisition unit 801 acquires ray information using a pulse signal output from a photoelectric converter, including energy information, arrival time, and attenuation time. The crystal region determination unit 803 determines the crystal cell where the ray will be deposited using the energy information and arrival time. The deposition location determination unit 805 determines the deposition location of the ray using the attenuation time and a pre-established lookup table. The lookup table includes the correspondence between the ray's attenuation time and the deposition location.

[0110] Figure 9 Another spatial decoding apparatus according to an embodiment of this application is shown. Figure 9 The spatial decoding device shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.

[0111] like Figure 9 As shown, the spatial decoding device is presented in the form of a general-purpose computing device. The components of this spatial decoding device may include, but are not limited to: at least one processor 910, at least one memory 920, a bus 930 connecting different system components (including the memory 920 and the processor 910), a display unit 940, etc. The memory 920 stores program code, which can be executed by the processor 910, causing the processor 910 to perform the methods described in this specification according to the various exemplary embodiments of this application. For example, the processor 910 can perform, as... Figure 6 The method shown.

[0112] The memory 920 may include a readable medium in the form of volatile memory cells, such as random access memory (RAM) 9201 and / or cache memory 9202, and may further include read-only memory (ROM) 9203.

[0113] The memory 920 may also include a program / utility 9204 having a set (at least one) of program modules 9205, including but not limited to: an operating system, one or more application programs, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.

[0114] Bus 930 can represent one or more of several types of bus structures, including a memory cell bus or memory cell controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus using any of the various bus structures.

[0115] The spatial decoding device can also communicate with one or more external devices 900 (e.g., keyboard, pointing device, Bluetooth device, etc.), one or more devices that enable a user to interact with the spatial decoding device, and / or any device that enables the spatial decoding device to communicate with one or more other computing devices (e.g., router, modem, etc.). This communication can be performed via input / output (I / O) interface 950. Furthermore, the spatial decoding device can communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 960. Network adapter 960 can communicate with other modules of the spatial decoding device via bus 930. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with the spatial decoding device, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0116] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. The technical solutions according to the embodiments of this application can be embodied in the form of a software product, which can be stored in a computer-readable storage medium (such as a CD-ROM, USB flash drive, or external hard drive) or on a network, including several computer program instructions to cause a computing device (such as a personal computer, server, or network device, etc.) to execute the methods described above according to the embodiments of this application.

[0117] Software products may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example,, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: electrical connections with one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0118] Computer-readable storage media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable storage medium may also be any readable medium other than a readable storage medium that can transmit, propagate, or transfer a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the readable storage medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0119] Program code for performing the operations of this application can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0120] The aforementioned computer-readable medium carries one or more program instructions that, when executed by a device, cause the computer-readable medium to perform the aforementioned functions.

[0121] Those skilled in the art will understand that the above modules can be distributed in the device as described in the embodiments, or they can be modified accordingly to be uniquely different from one or more devices in this embodiment. The multiple modules of the above embodiments can be combined into one module, or a single module can be further divided into multiple sub-modules.

[0122] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. The technical solutions according to the embodiments of this application can be embodied in the form of a software product, which can be stored in a computer-readable storage medium (such as a CD-ROM, USB flash drive, or external hard drive) or on a network, including several computer program instructions to cause a computing device (such as a personal computer, server, or network device, etc.) to execute the methods described above according to the embodiments of this application.

[0123] Software products may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example,, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: electrical connections with one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0124] Computer-readable storage media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable storage medium may also be any readable medium other than a readable storage medium that can transmit, propagate, or transfer a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the readable storage medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0125] Program code for performing the operations of this application can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0126] The aforementioned computer-readable medium carries one or more program instructions that, when executed by a device, cause the computer-readable medium to perform the aforementioned functions.

[0127] Those skilled in the art will understand that the above modules can be distributed in the device as described in the embodiments, or they can be modified accordingly to be uniquely different from one or more devices in this embodiment. The multiple modules of the above embodiments can be combined into one module, or a single module can be further divided into multiple sub-modules.

[0128] In traditional array scintillation crystal detectors, the detector's ability to acquire deposition projection location information is limited by the spatial resolution of the photoelectric conversion device array. According to some embodiments of this application, the decay time of each scintillation crystal strip in the scintillation crystal array is spatially encoded. The additional spatial information decoded from the decay time can be used to further locate the specific crystal strip where deposition occurred, thereby overcoming the limitation of the photoelectric conversion device array's spatial resolution on the detector's spatial resolution.

[0129] While this application provides the operational steps of the methods described in the above embodiments or flowcharts, the methods may include more or fewer operational steps based on conventional or non-inventive methods. For steps where there is no logically necessary causal relationship, the execution order of these steps is not limited to the execution order provided in the embodiments of this application.

[0130] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0131] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. Furthermore, any changes or modifications made by those skilled in the art based on the ideas of this application, and on the specific implementation methods and application scope of this application, are all within the scope of protection of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A spatially coded detector characterized by, include: A scintillation crystal array includes at least one crystal unit, wherein the crystal unit includes multiple crystal strips, at least some of the crystal strips in different crystal units have different decay times, at least two crystal strips in a crystal unit have different decay times, or the decay times of at least some of the crystal strips in a crystal unit are different from the decay times of at least one crystal strip, and the scintillation crystal array is configured to determine the crystal strips of corresponding specifications from a spatial location encoding table according to spatial resolution requirements, wherein the spatial location encoding table includes the correspondence between crystal strips of different decay times and different sizes and spatial resolutions; as well as A photoelectric converter, coupled to the crystal array, wherein the pulse signal output by the photoelectric converter acquires information about the radiation through a multi-voltage threshold sampling method.

2. The spatial coding detector according to claim 1, characterized in that, The at least one crystal unit is the same size.

3. The spatial coding detector according to claim 1, characterized in that, The scintillation crystal array comprises crystal units of at least two different sizes.

4. The spatial coding detector according to claim 2 or 3, characterized in that, The crystal bars in the crystal unit are arranged in a matrix, and the crystal bars at corresponding positions in different crystal units have the same decay time.

5. The spatial coding detector according to claim 1, characterized in that, The decay time of each of the crystal bars is different.

6. The spatial coding detector according to claim 5, characterized in that, The decay time of the crystal strips follows an arithmetic progression.

7. The spatial coding detector according to claim 5, characterized in that, The decay time of the crystal strip is between 30ns and 50ns.

8. The spatial coding detector according to claim 1, characterized in that, Some of the crystal strips have different external dimensions.

9. The spatial coding detector according to claim 1, characterized in that, The crystal strips may have a prism, cylinder, or irregular shape.

10. The spatial coding detector according to claim 1, characterized in that, The photoelectric converter is a photoelectric conversion device array, and each unit in the photoelectric conversion device array is coupled to the crystal strip in a one-to-one, one-to-many, or many-to-one manner.

11. A spatial coding method, characterized in that, The spatial coding method includes: A spatial position encoding table for a scintillation crystal array is established. The spatial position encoding table includes the correspondence between crystal strips of different decay times and sizes and spatial resolution. The scintillation crystal array includes at least one crystal unit, and the crystal unit includes multiple crystal strips. At least some of the crystal strips in different crystal units have different decay times. At least two crystal strips in a crystal unit have different decay times, or the decay times of at least some of the crystal strips in a crystal unit are different from the decay times of at least one crystal strip. According to the spatial resolution requirements, the crystal strips of the corresponding specifications are selected from the spatial location coding table to form the scintillation crystal array; The scintillation crystal array is coupled to the photoelectric converter according to a preset encoding order or preset encoding position. The pulse signal output by the photoelectric converter obtains the information of the ray through a multi-voltage threshold sampling method.

12. The spatial coding method according to claim 11, characterized in that, The spatial location coding table also includes the correspondence between the spatial resolution and the crystal bars of different positions, sizes or decay times arranged according to the preset coding order or the preset coding position.

13. The spatial encoding method according to claim 11, wherein the same spatial resolution corresponds to multiple forms of the preset encoding order or the preset encoding position.

14. The spatial coding method according to claim 11, characterized in that, The photoelectric converter is a photoelectric conversion device array, and each unit in the photoelectric conversion device array is coupled to the crystal strip in a one-to-one, one-to-many, or many-to-one manner.

15. A spatial decoding method, characterized in that, The spatial decoding method is used in a spatial coding detector as described in any one of claims 1-10, the spatial decoding method comprising: Information about the ray is obtained using the pulse signal output by the photoelectric converter. This information includes energy information, arrival time, and decay time. The information about the ray is obtained using a multi-voltage threshold sampling method. The energy information and the arrival time are used to determine the crystal unit of the X-ray deposition; The deposition location of the ray is obtained using the decay time and a pre-established lookup table, wherein the lookup table includes the correspondence between the decay time and the ray deposition location.

16. The method according to claim 15, characterized in that, The crystal unit for determining X-ray deposition includes: The crystal units of the X-ray deposition are determined using a one-to-one coupling method or a centroid method based on the coupling form between the scintillation crystal array and the photoelectric converter.

17. The method according to claim 15, characterized in that, The lookup table is pre-built in the following manner: The rays are detected using crystal strips of different specifications; Calculate the decay time of the rays deposited in each of the crystal strips; The lookup table is established using the calculated decay time and the deposition location of the ray in different crystal strips.

18. A spatial decoding device, characterized in that, The spatial decoding device is used in the spatial coding detector as described in any one of claims 1-10, the spatial decoding device comprising: The X-ray information acquisition unit is used to acquire X-ray information using the pulse signal output by the photoelectric converter. The information includes energy information, arrival time, and decay time. A crystal region determination unit is used to determine the crystal unit for X-ray deposition using the energy information and the arrival time; The deposition location determination unit is used to obtain the deposition location of the ray using the decay time and a pre-established lookup table, wherein the lookup table includes the correspondence between the decay time and the deposition location.

19. A spatial decoding device, characterized in that, include: One or more processors; Storage device for storing computer programs; When the computer program is executed by the one or more processors, the one or more processors cause the one or more processors to implement the method as described in any one of claims 15-17.

20. A storage medium, characterized in that, It stores program instructions that, when executed, implement the method as described in any one of claims 15-17.

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