Method for determining event region, method and device for processing inter-crystal scattering events, computer storage medium and computer program product

Abstract

The application discloses a method for determining an event region, a method and device for processing inter-crystal scattering events, a computer storage medium and a computer program product. The method comprises: determining the gathering position of non-scattering events and the position information of scattering events on each crystal strip based on the positioning information of a plurality of events in the crystal strip or the crystal array; and dividing the event region of the corresponding crystal strip based on the gathering position of non-scattering events and the position information of scattering events. In one aspect, the application does not depend on the one-to-one mapping relationship between the crystal strip and the photoelectric conversion device, is suitable for a complex coupling structure, and solves the problem that the traditional energy screening method is invalid in such a structure. In another aspect, the application can effectively distinguish and remove abnormal events located in the boundary region of the crystal strip, maximally weakens the interference of inter-crystal scattering on data reconstruction, and optimizes the overall coincidence time resolution of the system.

Description

Technical Field

[0001] This invention relates to the field of signal processing technology, and in particular to a method for determining an event region, a method and apparatus for processing intercrystalline scattering events, a computer storage medium, and a computer program product. Background Technology

[0002] Studies have found that due to the influence of the light emission process and optical propagation characteristics in scintillation crystals, a single gamma photon event often leads to multiple photoelectric conversion channels simultaneously receiving visible light signals, thereby triggering multiple time channels in most cases and degrading time resolution performance. Generally, the main causes of this phenomenon can be attributed to two categories: intercrystalline scattering and light diffusion. Among them, events formed by intercrystalline scattering significantly degrade the system's time resolution performance. To improve the accuracy and performance of information extracted from the detector, it is necessary to distinguish between these two types of events and process the events corresponding to intercrystalline scattering and light diffusion separately. In the one-to-one coupling structure of crystal strip – photoelectric conversion device – readout channel, light diffusion and intercrystalline scattering can usually be distinguished by multi-channel energy distribution characteristics, for example, by judging whether the total energy collected by the event is within a preset "energy window" to filter the event.

[0003] However, as Figure 1 As shown, when there is no one-to-one mapping between crystal strips 10 and photoelectric conversion devices 20, the energy of intercrystalline scattering events deposited in multiple crystal strips 10 will still be collected by the entire photoelectric conversion device array, and its total energy often still falls within the energy window. Moreover, the distribution of light signals corresponding to different crystal strip positions varies greatly in each channel, making it difficult to distinguish light diffusion through proportional relationships. Figure 2 (blue dashed arrow) and intercrystalline scattering ( Figure 1 (The yellow dashed arrow in the middle) causes this method to fail. Although light diffusion models can be established for different crystal strip positions, the modeling is complex and the accuracy is limited. At the same time, inter-crystal scattering is also mainly based on adjacent crystal strips in space, making it highly similar to light in the multi-channel energy distribution, thus significantly increasing the difficulty of distinguishing between the two in this coupled structure.

[0004] To address the aforementioned issues, existing technologies have proposed a position spectrum partitioning method based on fixed geometric boundaries. This method simply divides the position spectrum into uniform rectangular regions, the same number as the number of crystal strips in the crystal array, according to the physical grid of the crystal array. The problem is that inter-crystal scattering events can cause the reconstructed position to shift between two crystal strips, forming "connections" or outliers in the position spectrum. This simple rectangular partitioning cannot effectively distinguish and eliminate these anomalous events located in the crystal strip boundary regions, causing them to be mistakenly included as valid events in subsequent calculations, thus degrading the overall coincidence time resolution of the system.

[0005] Therefore, there is a lack of an effective method in the existing technology to accurately identify and eliminate inter-crystal scattering events in complex coupling structures between crystal strips and photoelectric conversion devices. Summary of the Invention

[0006] Therefore, it is necessary to provide a method for determining the event region, a method for processing intercrystalline scattering events, an apparatus, a computer storage medium, and a computer program product to address at least one technical problem existing in traditional solutions.

[0007] According to a first aspect of this application, a method for determining an event region is provided, comprising: determining the aggregation position of non-scattering events and the position information of scattering events corresponding to each crystal strip based on the positioning information of several events in a crystal strip or crystal array; and dividing the event region of the corresponding crystal strip based on the aggregation position of the non-scattering events and the position information of the scattering events.

[0008] According to one embodiment of this application, before determining the aggregation location of non-scattering events and the location information of scattering events corresponding to each crystal strip, the determination method further includes: collecting several events, calculating the position coordinates of each event on the crystal strip or crystal array through a predetermined position reconstruction algorithm, and determining the positioning information based on the position coordinates.

[0009] According to one embodiment of this application, determining the clustering location of scattering events corresponding to each crystal strip includes: determining the clustering location of non-scattering events corresponding to each crystal strip by means of local count maxima, or by means of a combination of local count maxima and crystal strip physical arrangement calibration.

[0010] According to one embodiment of this application, based on the positioning information of several events corresponding to crystal strips or crystal arrays, determining the aggregation position of non-scattering events corresponding to each crystal strip includes: forming the positioning information into a two-dimensional position spectrum, and forming the aggregation position into a light spot on the two-dimensional position spectrum.

[0011] According to one embodiment of this application, based on the positioning information of several events in a crystal bar or crystal array, the aggregation position of non-scattering events corresponding to each crystal bar is determined, including: forming the positioning information into a list of count data related to the coordinates of the corresponding events, and combining the coordinates that satisfy the following conditions: adjacent coordinate positions or coordinate position difference less than a first preset value, and the corresponding count data volume greater than a second preset value, or arranged in descending order at the first predetermined position, as the aggregation position.

[0012] According to one embodiment of this application, dividing the event region of the corresponding crystal strip based on the aggregation location of the non-scattering event and the location information of the scattering event includes: setting a boundary around the aggregation location, and the region within the boundary forming the event region.

[0013] According to one embodiment of this application, dividing the event region of the corresponding crystal strip based on the aggregation location of the non-scattering event and the location information of the scattering event includes: associating the distance between each point on the boundary and the center of the corresponding aggregation location with the occurrence rate of intercrystalline scattering events at the location corresponding to the point.

[0014] According to one embodiment of this application, the distances between each point on the boundary and the center of the aggregation location are different.

[0015] According to one embodiment of this application, dividing the event region of a corresponding crystal strip based on the aggregation position of the non-scattering event and the location information of the scattering event includes: dividing the event region of a corresponding crystal strip based on the aggregation position, the location information of the scattering event, and the relative position of the corresponding crystal strip and adjacent crystal strips.

[0016] According to one embodiment of this application, the shape of the event area can be any one of a rectangle, an irregular shape, a circle, or an ellipse.

[0017] According to one embodiment of this application, the event regions corresponding to different crystal strips in the same crystal array may have the same shape, not exactly the same shape, or completely different shape.

[0018] According to one embodiment of this application, the event region of the corresponding crystal strip is divided based on the aggregation position of the non-scattering event and the position information of the scattering event, including: setting one event region for each crystal strip.

[0019] According to a second aspect of this application, a method for processing intercrystalline scattering events is provided, comprising: for each detected event, if the detected event is located within the event region, it is identified as a valid event; otherwise, it is identified as an intercrystalline scattering event and discarded.

[0020] According to a third aspect of this application, an event region determination apparatus is provided, comprising: a clustering location determination unit configured to determine the clustering location of non-scattering events and the location information of scattering events on each crystal strip based on the positioning information corresponding to several events in a crystal strip or crystal array; and a region determination unit configured to divide the event region of the corresponding crystal strip based on the clustering location of the non-scattering events and the location information of the scattering events.

[0021] According to one embodiment of this application, the determining device further includes: a position spectrum determining unit, configured to collect a plurality of events, calculate the position coordinates of each event on a crystal strip or crystal array using a predetermined position reconstruction algorithm, and determine the positioning information based on the position coordinates of all events.

[0022] According to one embodiment of this application, the aggregation location determination unit is configured to determine the aggregation location of scattering events on each crystal strip by means of local count maxima, or by means of a combination of local count maxima and crystal strip physical arrangement calibration.

[0023] According to one embodiment of this application, the aggregation location determination unit is configured to form the positioning information into a two-dimensional location spectrum and to form the aggregation location as a light spot on the two-dimensional location spectrum.

[0024] According to one embodiment of this application, the aggregation location determination unit is configured to form the positioning information into a list of count data related to the coordinates of the corresponding event, and to combine the coordinates that satisfy the following conditions: the coordinates are adjacent or the difference between the coordinates is less than a first preset value, and the corresponding count data is greater than a second preset value, or the coordinates are arranged in descending order at the first predetermined position as the aggregation location.

[0025] According to one embodiment of this application, the region determination unit is configured to set a boundary around the aggregation location, and the region within the boundary forms the event region.

[0026] According to one embodiment of this application, the region determination unit is configured to correlate the distance between each point on the boundary and the center of the corresponding aggregation location with the occurrence rate of intercrystalline scattering events at the location corresponding to the point.

[0027] According to one embodiment of this application, the distances between each point on the boundary and the center of the aggregation location are different.

[0028] According to one embodiment of this application, the region determination unit is configured to divide the event region of the corresponding crystal strip based on the aggregation location, the scattering event location information, and the relative position of the corresponding crystal strip with adjacent crystal strips.

[0029] According to one embodiment of this application, the shape of the event area can be any one of a rectangle, an irregular shape, a circle, or an ellipse.

[0030] According to one embodiment of this application, the event regions corresponding to different crystal strips in the same crystal array may have the same shape, not exactly the same shape, or completely different shape.

[0031] According to one embodiment of this application, the region determination unit is configured to provide one event region on each crystal strip.

[0032] According to a fourth aspect of this application, an apparatus for processing intercrystalline scattering events is provided, the apparatus being configured such that for each detected event, if the detected event is located within the event region, it is considered a valid event; otherwise, it is considered an intercrystalline scattering event and discarded.

[0033] According to a fifth aspect of this application, a computer storage medium is provided that stores a computer program thereon, which, when executed by a processor, implements the steps of the determination method and / or the processing method described herein.

[0034] According to a sixth aspect of this application, a computer program product is provided, comprising a computer program or instructions, wherein the steps of the determination method and / or the processing method are executed by a processor.

[0035] The method for determining the event region, the method and apparatus for processing inter-crystal scattering events, the computer storage medium, and the computer program product provided in this application associate the event region corresponding to the crystal strip with the aggregation location of non-scattering events and the location information of scattering events. On the one hand, it does not rely on the one-to-one mapping relationship between the crystal strip and the photoelectric conversion device, making it suitable for complex coupling structures and solving the problem of the failure of traditional energy sieving methods in such structures. On the other hand, instead of simply dividing the position spectrum into uniform rectangular regions with the same number of crystal strips as the physical grid of the crystal array, it can effectively distinguish and eliminate abnormal events located in the boundary region of the crystal strip, minimizing the interference of inter-crystal scattering on data reconstruction and optimizing the overall coincidence time resolution of the system. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of a non-one-to-one mapping coupling between a scintillation crystal bar and a photoelectric conversion device. Figure 2 This is a flowchart illustrating a method for determining an event region in one embodiment of this application; Figure 3 This is a flowchart illustrating a method for determining an event region in another embodiment of this application; Figure 4 This is a schematic diagram of the position spectrum determined by the method in one embodiment of this application; Figure 5 This is a schematic diagram of the event region determined by the method in one embodiment of this application; Figure 6 This is a flowchart illustrating a method for handling one of the intercrystalline scattering events in this application; Figure 7(a) shows the coincidence time difference distribution obtained by the position spectrum division method based on fixed geometric boundaries; Figure 7(b) is a distribution of the time difference of conformity obtained using the determination method of this application; Figure 8 To obtain a time difference distribution map by separately statistically analyzing the events excluded by the determination method provided in this application; Figure 9(a) shows the energy distribution characteristics of scattering events obtained from the scattering process between non-adjacent crystals; Figure 9(b) shows the energy distribution characteristics of scattering events obtained from the scattering process between adjacent crystals; Figure 9(c) shows the energy distribution characteristics of non-scattering events; Figure 10 The coincidence time difference distribution of the excluded scattering events; Figure 11 This is a schematic diagram of the structure of the event region determination device in one embodiment of this application; Figure 12 This is a schematic diagram of the structure of the event region determination device in another embodiment of this application; Figure 13 This is a schematic diagram of the structure of a screening device for intercrystalline scattering events in one embodiment of this application; Figure 14 This is a schematic diagram of the structure of a computer system in one embodiment of this application; Figure 15 This is an internal structural diagram of a computer device in one embodiment of this application. Detailed Implementation

[0038] To make the above-mentioned objectives, features, and advantages of this application more readily understood, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0039] It should be noted that when an element is said to be "fixed to" another element, it can be directly fixed to the other element or there may be an intervening element. When an element is said to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "substantially equal" or "substantially equal to" as used herein mean that the difference between the two lies within a range of errors considered equivalent in the art. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The terms “and / or” or “and / or” as used herein include any and all combinations of one or more of the associated listed items.

[0041] To address the technical problems existing in the prior art, this application proposes a method, apparatus, and supporting applications for determining the event region that can at least assist in eliminating intercrystalline scattering events in complex coupled structures.

[0042] In some embodiments, the method for determining the event region can be executed by an event region determining device. For example, the method for determining the event region can be partially or wholly stored in a storage device (such as the built-in storage module of the detection device or an external storage device) in the form of a program or instructions, which, when executed, can implement the method for determining the event region. The event region determining device disclosed in this application for implementing the above-described method for determining the event region can be a device with abundant computing resources (e.g., a computer, server, cloud computing, etc.) or a device with limited computing resources (e.g., FPGA (Field Programmable Gate Array) chip board, ASIC (Application-Specific Integrated Circuit) chip board, and other hardware circuits).

[0043] The following description, with reference to the accompanying drawings, illustrates some preferred embodiments of the present application. It should be noted that the following description is for illustrative purposes only and is not intended to limit the scope of protection of this application.

[0044] Figure 2 This is a flowchart illustrating a method for determining an event region in one embodiment of this application; Figure 3 This is a flowchart illustrating a method for determining an event region in another embodiment of this application. In one embodiment, the method for determining the event region may include steps 100-300. It should be noted that step 100 is optional, and the determination method provided in this application can determine the event region based on the pre-processed event location; that is, the method steps provided in this application can be executed starting from step 200.

[0045] Step 100: Collect several events, and calculate the position coordinates of each event on the crystal bar or crystal array using a predetermined position reconstruction algorithm, and determine the location information of the event based on the position coordinates.

[0046] Generally, crystal bars or crystal arrays are coupled to photoelectric conversion devices, and a readout electronics section is connected to the back end to form a detector, which collects several events. A single crystal bar in a crystal bar or crystal array can be coupled one-to-one with a photoelectric conversion device, indicating a one-to-one mapping relationship between the crystal bar and the photoelectric conversion device. Alternatively, multiple crystal bars can be coupled to a single photoelectric conversion device; for example, an array containing 20×20 crystal bars can be coupled to an array containing 8×8 SiPMs, in which case there is no one-to-one mapping relationship between the crystal bars and the photoelectric conversion device. Figure 1 The method for determining the event region provided in this application is particularly applicable to situations where there is no one-to-one mapping relationship between the crystal strip and the photoelectric conversion device.

[0047] The crystal strip can be any one of NaI, CsI, LYSO, YSO, LaBr3:Ce, or BGO, and the photoelectric conversion device can be any one of a photomultiplier tube (PMT), photodiode, or silicon photomultiplier (SiPM), preferably SiPM. The function of the crystal strip is to convert X-rays into visible light signals, and the function of the photoelectric conversion device is to convert visible light signals into scintillation pulses. Further, the scintillation pulses are digitally sampled by the readout electronics at the back end of the photoelectric conversion device. Taking multi-voltage threshold sampling as an example, multiple voltage thresholds need to be preset using a digital-to-analog converter (DAC) before sampling. By recording the time information of the scintillation pulse crossing these voltage thresholds, a series of "time-voltage" pairs are obtained. Then, combined with prior information about the scintillation pulses, the original information of the pulses is restored through a fitting method, including the position, energy, and time information of the original signal. The original signal is processed to obtain several events. This process can be implemented using methods already described in the prior art, and will not be elaborated upon in this application.

[0048] The predetermined position reconstruction algorithm can be any one of the following: light diffusion energy weighting method, centroid algorithm, maximum likelihood localization method, machine learning and deep learning algorithms, etc.; the position coordinates can be two-dimensional coordinates (X, Y). Typically, these two-dimensional coordinates correspond to the cross-section of the scintillation crystal array. That is, the cross-section of each crystal strip in the scintillation crystal array occupies a certain area in the two-dimensional coordinate plane. By determining whether the two-dimensional coordinates are located within the corresponding area region, it can be determined which crystal strip in the scintillation crystal array corresponds to the scintillation pulse event, thereby determining the specific crystal strip position where the gamma photons are deposited.

[0049] Step 200: Based on the location information of several events in the crystal strip or crystal array, determine the aggregation position of the non-scattering events and the location information of the scattering events corresponding to each crystal strip.

[0050] Non-scattering events, also known as normal single-crystal events, are events that do not involve scattering. It's important to note that a large number of normal events exist within a crystal strand. In the position spectrum corresponding to the strand, these normal events generally cluster at or around a fixed location. Scattered scattering events, on the other hand, are generally more dispersed and do not cluster at a single location. Therefore, the degree of clustering can be used to determine the location of non-scattering events and the location of scattering events. For example, if a certain number or proportion of events cluster around the same point, then the location formed by these events around that point can be considered the clustering location of non-scattering events, and the other events are scattering events.

[0051] Further, step 200 may include: determining the aggregation location of non-scattering events on each crystal strip by means of local count maxima, or by means of a combination of local count maxima and crystal strip physical arrangement calibration.

[0052] The physical arrangement calibration of crystal strips can be understood as the calibration information such as the known arrangement of the crystal array and the physical dimensions of each crystal strip. For example, the crystal array may have 20 crystal strips in 20 rows and 20 in 20 columns, or 10 crystal strips in 10 rows and 10 in 10 columns, or 16 crystal strips in 18 in 16 columns, or others. The rectangular cross-sectional dimensions of the crystal strips may be 1mm×1mm, 2mm×2mm, or 1mm×2mm, or others. A crystal strip refers to a scintillation crystal strip. Generally, there is only one aggregation location for non-scattering events in a single crystal strip. Therefore, combining local count maxima with the physical arrangement calibration of crystal strips can more accurately and quickly determine the aggregation location of non-scattering events on each crystal strip. Specifically, in one example, the locations of a large number of events collected by the detector are first reconstructed, the distribution of each event in the location spectrum is statistically analyzed, and the counts are accumulated according to the two-dimensional location coordinates to form a location spectrum. Since the energy deposition locations of non-scattering events are relatively stable, they usually appear as high-count aggregation regions near the corresponding crystal locations in the location spectrum. Subsequently, local maxima are searched in the position spectrum using a local maximum algorithm, and combined with the actual physical arrangement of the crystal array, the aggregation location of non-scattering events on each crystal strip is determined. Further, step 200 may include: forming the positioning information into a two-dimensional position spectrum, and forming the aggregation location as a light spot on the two-dimensional position spectrum.

[0053] As an alternative example, besides forming the location information into a two-dimensional location spectrum, it can also be expressed using coordinates and count data, forming a list of count data related to the coordinates of the corresponding event. Coordinates that meet the following conditions are combined to form the clustered location: adjacent coordinate positions or coordinate position differences less than a first preset value, and corresponding count data greater than a second preset value or arranged in descending order at the first predetermined position. The first preset value, second preset value, and predetermined position can all be set based on experience in the corresponding application scenario.

[0054] Preferably, the positioning information is formed into a two-dimensional location spectrum, and the clustered locations are formed into light spots on the two-dimensional location spectrum, because this allows for a more intuitive observation of low-count data. For example... Figure 4 As shown, a two-dimensional position spectrum of a 20×20 crystal array is illustrated, where the light spots represent aggregation sites. (The image shows the position spectrum of a 20×20 crystal array.) Figure 4 In addition to the 20×20 clustered locations, bright spots distributed between the crystal stripes can be clearly observed. These "connecting" structures distributed along the row or column direction are usually caused by inter-crystal scattering; while the irregularly distributed isolated white noise spots mostly originate from inter-crystal scattering events, and their calculated positions are highly random. Therefore, by observing the specific distribution of an event in the position spectrum, it is possible to deduce whether the event is an inter-crystal scattering event, thus distinguishing between them.

[0055] Step 300: Divide the event regions of the corresponding crystal strips based on the aggregation location of the non-scattering events and the location information of the scattering events.

[0056] Each crystal strip is assigned a unique event region. The boundary of this event region is not a simple rectangle, but rather customized based on the aggregation locations of non-scattering events and the statistical distribution of scattering event locations within the crystal strip. This allows for a refined and non-uniform division of the position spectrum. Furthermore, the event region can be further customized by combining the aggregation and scattering event location information with the relative positions of the crystal strip and its adjacent crystal strips. These relative positions provide the boundaries for each crystal strip, preventing event regions from spanning multiple crystal strips.

[0057] For example, the boundary of the event region can be any one of a rectangle, an irregular shape, a circle, or an ellipse. It is understood that the shapes of the event regions on different crystal strips in the same crystal array may be the same, not exactly the same, or completely different. Furthermore, one event region is provided on each crystal strip.

[0058] Specifically, step 300 may include: setting a boundary around the gathering location, with the area within the boundary forming the event area.

[0059] Generally, the boundary of the event region is outside the corresponding gathering location, that is, the event region surrounds the corresponding gathering location.

[0060] In the example where the location information is formed into a two-dimensional position spectrum, the boundary can be directly delineated outside the light spot in the image to form an event region. However, it is important to note that the size and boundary of the event region need to be considered based on two scenarios: accurate rejection of scattering events and loss of true events due to erroneous rejection. In a preferred example, the distance between each point on the boundary and the center of the corresponding aggregation location is correlated with the occurrence rate of intercrystalline scattering events at the location corresponding to that point. For example, in directions where intercrystalline scattering is frequent (usually along the row or column direction of the crystal array), the boundary is set more strictly (i.e., closer to the center of the corresponding aggregation location) to cut off the "connection" with adjacent crystal strips. In other directions, the boundary can be set relatively loosely to accommodate the normal statistical fluctuations of the crystal strip. Figure 5 The diagram shows a schematic of the position spectrum after division in an example, illustrating a refined, non-uniform rectangular division of the position spectrum. In this diagram, white dots represent the clustering locations of non-scattering events, and red lines represent the boundaries surrounding the clustering locations. For each clustering location, the region within the adjacent boundary is the event region of the crystal strip corresponding to that clustering location.

[0061] In the example where location information is formed into a list of count data related to event coordinates, the event region can be delineated based on the statistical distribution formed by the correspondence between the count data and coordinates provided in the list. Here, the event region is expressed by the range of location coordinates, which can be formed by extending the event region outwards to the four quadrants with the center coordinates of the clustered location as (0,0). Understandably, the size and boundaries of the event region also need to be considered when delineating it, taking into account both the accurate removal of scattering events and the loss of true events due to erroneous removal. The strategy used can be the same as or similar to that in the example where location is formed into a two-dimensional location spectrum.

[0062] Preferably, since the probability of a scattering event occurring at different points within the event area is different, generally, the distance between each point on the boundary and the center of the aggregation location is different.

[0063] The determination method provided in this application, by associating the event region on the corresponding crystal strip with the aggregation location of non-scattering events and the location information of scattering events, does not rely on a one-to-one mapping relationship between the crystal strip and the photoelectric conversion device, making it applicable to complex coupling structures and solving the problem of the failure of traditional energy sieving methods in such structures. On the other hand, instead of simply dividing the position spectrum into uniform rectangular regions of the same number as the number of crystal strips in the crystal array according to the physical grid of the crystal array, it can effectively distinguish and eliminate abnormal events located in the boundary region of the crystal strip, minimizing the interference of inter-crystal scattering on data reconstruction and optimizing the overall coincidence time resolution of the system.

[0064] It should be noted that the method for determining the event region provided in this application can generally be performed during the testing or maintenance phase after the detector assembly is completed. The event region corresponding to each crystal strip can be determined and directly used in subsequent event detection to screen out inter-crystal scattering events.

[0065] Corresponding to the method for determining the event region described above, this application also provides a method for processing intercrystalline scattering events, such as... Figure 6 As shown, the processing method provided in this application includes step 400: for each detected event, if the detected event is located within the event region, it is considered a valid event; otherwise, it is considered an intercrystalline scattering event and discarded.

[0066] Specifically, in this application example, step 400 includes: for each detected event, reconstructing its position coordinates, determining whether the position coordinates fall within the event region; if so, it is considered a valid event; otherwise, it is considered an intercrystalline scattering event and discarded. Thus, in subsequent processing, only the retained valid events have their time information extracted for calculations that meet performance parameters such as time resolution.

[0067] To better illustrate the advantages of this application, the position spectrum of the same detector was divided using both the existing fixed geometric boundary-based position spectrum division method and the determination method provided in this application. The tested detector used a 20×20 crystal array coupled with an 8×8 SiPM array, and there was no one-to-one mapping between the crystal strips and the SiPMs. All response lines (LORs) were plotted for the obtained valid events to obtain the Gaussian distribution of the events, and the coincidence time resolution (CTR) was calculated. The results are shown in Figures 7(a) and 7(b). Figure 7(a) shows the coincidence time difference distribution obtained using the fixed geometric boundary-based position spectrum division method, and Figure 7(b) shows the coincidence time difference distribution obtained using this application. The horizontal axis represents time, the vertical axis represents event counts, the blue dots represent the time spectrum, and the red curves represent Gaussian fitting curves.

[0068] The results show that, by processing data based on fixed geometric boundaries, and by simply dividing the region based on the location reconstruction results without effectively identifying and removing intercrystalline scattering events, the resulting coincidence time difference distribution map exhibits a tail structure on the left side that significantly deviates from the Gaussian morphology. This indicates that, in addition to normal single-crystal stripe deposition events, events with different temporal characteristics are still included in the statistics. As a result, the coincidence time resolution is also low, at 403.3 ps.

[0069] In contrast, the method provided in this application filters out intercrystalline scattering events based on location discrimination, making the statistical sample closer to a set of events with a single time response characteristic. After filtering, the consistency between the time difference distribution and the Gaussian fitting results is significantly improved, and the final time resolution is optimized to 365.9 ps. This result demonstrates that the method provided in this application can effectively improve the time performance of the system.

[0070] To further analyze the impact of intercrystalline scattering on time-resolved performance, the events eliminated by the method provided in this application were statistically analyzed separately, and their time difference distribution was analyzed, such as... Figure 8 As shown in Figure 9, the meanings of the parameters are the same as in Figure 7. The results show that the overall temporal distribution of the removed events still approximately follows a Gaussian distribution, but the tail components that deviate from the main Gaussian distribution in the original time spectrum are also mainly included in this type of event, corresponding to the area marked by the green box in the figure. For the anomalous time events within the green box, their energy distribution characteristics on the SiPM array are further traced. The analysis found that such events usually appear as two luminescent centers with a large spatial distance on the array [Figure 9(a)], indicating that they mainly originate from the scattering process between non-adjacent crystal strips. In contrast, the energy distribution of inter-crystal scattering events outside the green box mostly appears as two luminescent centers with a relatively close spatial distance [Figure 9(b)], corresponding to scattering between adjacent crystals. For comparison, Figure 9(c) shows the energy distribution characteristics of non-scattering events, where energy is represented by gray values, with lower gray values ​​indicating higher energy.

[0071] Based on the above differences, the effect of intercrystalline scattering on time-resolved performance can be approximately decomposed into two types of Gaussian components in the time difference distribution, such as... Figure 10 As shown. Two types of scattering events (Gaussian fitted curves are respectively) Figure 10 The green and red curves in the graph correspond to different contributions to temporal degradation, and together they form the structure in the original time spectrum that deviates from the ideal single Gaussian distribution.

[0072] From a physical perspective, multi-channel triggering caused by intercrystalline scattering not only reduces the amplitude and slows the rise time of single-channel signals, but also affects the judgment of time signals, mistaking the time of scattered events for the actual event time, thus degrading the detector's timing performance. Therefore, the method provided in this application identifies and eliminates such scattering events, which can reduce time broadening and improve the system's timing performance.

[0073] Based on the description of the above-described method embodiments for determining event regions, this application also provides an apparatus for determining event regions. The apparatus may include devices (including distributed systems), software (applications), modules, components, servers, clients, etc., using the methods described in the embodiments of this specification, combined with necessary hardware implementations. Based on the same inventive concept, the apparatuses in one or more embodiments provided in this application are as described in the following embodiments. Since the implementation schemes and methods for solving the problem by the apparatus are similar, the implementation of specific apparatuses in the embodiments of this specification can refer to the implementation of the foregoing methods, and repeated details will not be elaborated further. As used below, the terms "module" or "module group" can refer to a combination of software and / or hardware that implements a predetermined function. Although the apparatuses described in the following embodiments are preferably implemented in software, hardware implementations, or a combination of software and hardware, are also possible.

[0074] Figure 11 This is a schematic diagram of the structure of the event region determination device in one embodiment of this application; Figure 12 This is a schematic diagram of the structure of an event region determination device in one embodiment of this application. In one embodiment, the event region determination device 1100 may include a location spectrum determination unit 1100, a cluster location determination unit 1200, and a region determination unit 1300. It should be noted that the location spectrum determination unit 1100 is an optional unit, and the determination device 1100 provided in this application can determine the event region based on the event location that has been pre-processed.

[0075] Specifically, the position spectrum determination unit 1100 is configured to collect several events and calculate the position coordinates of each event on the crystal strip or crystal array through a predetermined position reconstruction algorithm, and determine the positioning information of the events based on the position coordinates of all events.

[0076] Generally, a crystal bar or crystal array is coupled to a photoelectric conversion device, and a readout electronics section is connected to the back end to form a detector, which collects several events. A single crystal bar in the crystal bar or crystal array can be coupled one-to-one with the photoelectric conversion device, indicating a one-to-one mapping relationship between the crystal bar and the photoelectric conversion device. Alternatively, multiple crystal bars can be coupled to a single photoelectric conversion device; for example, an array containing 20×20 crystal bars can be coupled to an array containing 8×8 SiPMs, where no one-to-one mapping relationship exists between the crystal bars and the photoelectric conversion device. The event region determination device provided in this application is particularly suitable for situations where no one-to-one mapping relationship exists between the crystal bars and the photoelectric conversion device.

[0077] The crystal strip can be any one of NaI, CsI, LYSO, YSO, LaBr3:Ce, or BGO, and the photoelectric conversion device can be any one of a photomultiplier tube (PMT), photodiode, or silicon photomultiplier (SiPM), preferably SiPM. The function of the crystal strip is to convert X-rays into visible light signals, and the function of the photoelectric conversion device is to convert visible light signals into scintillation pulses. Further, the scintillation pulses are digitally sampled by the readout electronics at the back end of the photoelectric conversion device. Taking multi-voltage threshold sampling as an example, multiple voltage thresholds need to be preset using a digital-to-analog converter (DAC) before sampling. By recording the time information of the scintillation pulse crossing these voltage thresholds, a series of "time-voltage" pairs are obtained. Then, combined with prior information about the scintillation pulses, the original information of the pulses is restored through a fitting method, including the position, energy, and time information of the original signal. The original signal is processed to obtain several events. This process can be implemented using methods already described in the prior art, and will not be elaborated upon in this application.

[0078] The predetermined position reconstruction algorithm can be any one of the following: light diffusion energy weighting method, centroid algorithm, maximum likelihood localization method, machine learning and deep learning algorithms, etc.; the position coordinates can be two-dimensional coordinates (X, Y). Typically, these two-dimensional coordinates correspond to the cross-section of the scintillation crystal array. That is, the cross-section of each crystal strip in the scintillation crystal array occupies a certain area in the two-dimensional coordinate plane. By determining whether the two-dimensional coordinates are located within the corresponding area region, it can be determined which crystal strip in the scintillation crystal array corresponds to the scintillation pulse event, thereby determining the specific crystal strip position where the gamma photons are deposited.

[0079] Specifically, the aggregation location determination unit 1200 is configured to determine the aggregation location of non-scattering events and the location information of scattering events on each crystal strip based on the positioning information of several events in the crystal strip or crystal array.

[0080] Non-scattering events, also known as normal single-crystal stripe events, are events that do not involve scattering. It's important to note that a large number of normal events exist within a crystal stripe. In the position spectrum corresponding to the stripe, these normal events generally cluster at or around a fixed location. In contrast, scattered events are generally more dispersed and do not cluster at a single location. Therefore, the degree of clustering can be used to determine the location of both non-scattering and scattering events.

[0081] Furthermore, the aggregation location determination unit 1200 is configured to determine the aggregation location of scattering events on each crystal strip by means of local count maxima, or by means of a combination of local count maxima and crystal strip physical arrangement calibration.

[0082] The physical arrangement calibration of crystal strips can be understood as the calibration information such as the known arrangement of the crystal array and the physical dimensions of each crystal strip. For example, the crystal array may have 20 crystal strips in 20 rows and 20 in 20 columns, or 10 crystal strips in 10 rows and 10 in 10 columns, or 16 crystal strips in 18 in 16 columns, or others. The rectangular cross-sectional dimensions of the crystal strips may be 1mm×1mm, 2mm×2mm, or 1mm×2mm, or others. A crystal strip refers to a scintillation crystal strip. Generally, there is only one aggregation location for non-scattering events in a single crystal strip. Therefore, combining local count maxima with the physical arrangement calibration of crystal strips can more accurately and quickly determine the aggregation location of non-scattering events on each crystal strip. Specifically, in one example, the locations of a large number of events collected by the detector are first reconstructed, the distribution of each event in the location spectrum is statistically analyzed, and the counts are accumulated according to the two-dimensional location coordinates to form a location spectrum. Since the energy deposition locations of non-scattering events are relatively stable, they usually appear as high-count aggregation regions near the corresponding crystal locations in the location spectrum. Subsequently, local maximum points are searched in the position spectrum using a local maximum algorithm. Combined with the actual physical arrangement of the crystal array, the aggregation location of non-scattering events on each crystal strip is determined.

[0083] Furthermore, the aggregation location determination unit 1200 is configured to form the positioning information into a two-dimensional location spectrum and to form the aggregation location into a light spot on the two-dimensional location spectrum.

[0084] As an alternative example, besides forming the location information into a two-dimensional location spectrum, it can also be expressed using coordinates and count data, forming a list of count data related to the coordinates of the corresponding event. Coordinates that meet the following conditions are combined to form the clustered location: adjacent coordinate positions or coordinate position differences less than a first preset value, and corresponding count data greater than a second preset value or arranged in descending order at the first predetermined position. The first preset value, second preset value, and predetermined position can all be set based on experience in the corresponding application scenario.

[0085] Preferably, the positioning information is formed into a two-dimensional location spectrum, and the clustered locations are formed into light spots on the two-dimensional location spectrum, because this allows for a more intuitive observation of low-count data. For example... Figure 4 As shown, a two-dimensional position spectrum of a 20×20 crystal array is illustrated, where the light spots represent aggregation sites. (The image shows the position spectrum of a 20×20 crystal array.) Figure 4 In addition to the 20×20 clustered locations, bright spots distributed between the crystal stripes can be clearly observed. These "connecting" structures distributed along the row or column direction are usually caused by inter-crystal scattering; while the irregularly distributed isolated white noise spots mostly originate from inter-crystal scattering events, and their calculated positions are highly random. Therefore, by observing the specific distribution of an event in the position spectrum, it is possible to deduce whether the event is an inter-crystal scattering event, thus distinguishing between them.

[0086] Specifically, the region determination unit 1300 is configured to divide the event region of the corresponding crystal strip based on the aggregation position of the non-scattering event and the position information of the scattering event.

[0087] Each crystal strip is assigned a unique event region. The boundary of this event region is not a simple rectangle, but rather customized based on the aggregation locations of non-scattering events and the statistical distribution of scattering event locations within the crystal strip. This allows for a refined and non-uniform division of the position spectrum. Furthermore, the event region can be further customized by combining the aggregation locations and scattering event locations with the relative positions of the crystal strip and its adjacent crystal strips. These relative positions provide the boundaries of each crystal strip, preventing event regions from crossing crystal strips.

[0088] For example, the boundary of the event region can be any one of a rectangle, an irregular shape, a circle, or an ellipse. It is understood that the shapes of the event regions on different crystal strips in the same crystal array may be the same, not exactly the same, or completely different. Furthermore, one event region is provided on each crystal strip.

[0089] Specifically, the region determination unit 1300 is configured to set a boundary around the gathering location, and the region within the boundary forms the event region.

[0090] Generally, the boundary of the event region is outside the corresponding gathering location, that is, the event region surrounds the corresponding gathering location.

[0091] In the example of positioning to form a two-dimensional positional spectrum, the boundary can be directly delineated outside the light spot in the image to form the event region. However, it is important to note that the size and boundary of the event region need to be considered based on two scenarios: accurate removal of scattering events and loss of true events due to erroneous removal. In a preferred example, the distance between each point on the boundary and the center of the corresponding aggregation location is correlated with the occurrence rate of intercrystalline scattering events at the corresponding location. For example, in directions with high intercrystalline scattering (usually along the row or column direction of the crystal array), the boundary is set more strictly (i.e., closer to the center of the corresponding aggregation location) to cut off the "connection" with adjacent crystal strips. In other directions, the boundary can be set relatively loosely to accommodate the normal statistical fluctuations of the crystal strip. Figure 5 The diagram shows a schematic of the position spectrum after division in an example, illustrating a refined, non-uniform rectangular division of the position spectrum. In this diagram, white dots represent the clustering locations of non-scattering events, and red lines represent the boundaries surrounding the clustering locations. For each clustering location, the region within the adjacent boundary is the event region of the crystal strip corresponding to that clustering location.

[0092] In the example where location information is formed into a list of count data related to event coordinates, event regions can be divided based on the statistical distribution formed by the correspondence between the count data and coordinates provided in the list. Here, the event region is expressed by the range of location coordinates, which can be formed by expanding outwards to the four quadrants with the center coordinates of the clustered location as (0,0). Understandably, the size and boundaries of the event region also need to be considered during the division, taking into account both the accurate removal of scattering events and the loss of true events due to erroneous removal. The strategy used can be the same as or similar to that in the example where location is formed into a two-dimensional location spectrum.

[0093] Preferably, since the probability of a scattering event occurring at different points within the event area is different, generally, the distance between each point on the boundary and the center of the aggregation location is different.

[0094] The determining device 1100 provided in this application associates the event region on the corresponding crystal strip with the aggregation position of non-scattering events and the position information of scattering events. On the one hand, it does not rely on the one-to-one mapping relationship between the crystal strip and the photoelectric conversion device, making it suitable for complex coupling structures and solving the problem of failure of traditional energy sieving methods in such structures. On the other hand, instead of simply dividing the position spectrum into uniform rectangular regions with the same number of crystal strips as the physical grid of the crystal array, it can effectively distinguish and eliminate abnormal events located in the boundary region of the crystal strip, minimizing the interference of inter-crystal scattering on data reconstruction and optimizing the overall coincidence time resolution of the system.

[0095] It should be noted that the event region determination device 1100 provided in this application can generally be used during the testing or maintenance phase after the detector assembly is completed to determine the event region corresponding to each crystal strip. It can be directly used in subsequent event detection to screen out inter-crystal scattering events.

[0096] Corresponding to the above-mentioned method and / or apparatus for determining the event region, in the embodiments of this application, such as Figure 13 As shown, this application also provides a screening device 1300 for intercrystalline scattering events. The screening device 1300 is configured such that for each detected event, if the detected event is located within the event region as described in the above embodiments, it is considered a valid event; otherwise, it is considered an intercrystalline scattering event and is rejected.

[0097] Specifically, in this application example, the screening device 1300 is configured to reconstruct the position coordinates of each detected event, determine whether the position coordinates fall within the event region, and if so, identify it as a valid event; otherwise, identify it as an intercrystalline scattering event and discard it. Thus, in subsequent processing, only the time information of the retained valid events is extracted for calculations of performance parameters such as time resolution. For the beneficial effects and comparative examples of this device, please refer to the embodiments of the above processing method, which will not be repeated here.

[0098] It should be understood that Figures 11-13The apparatus and modules shown can be implemented in various ways. For example, in some embodiments, the apparatus and modules can be implemented in hardware, software, or a combination of both. The hardware portion can be implemented using dedicated logic; the software portion can be stored in memory and executed by a suitable instruction execution device, such as a microprocessor or dedicated-design hardware. Those skilled in the art will understand that the methods and apparatus described above can be implemented using computer-executable instructions and / or included in processor control code, for example, such code provided on a carrier medium such as a disk, CD, or DVD-ROM, a programmable memory such as read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The apparatus and modules described in this application can be implemented not only with hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field-programmable gate arrays, programmable logic devices, etc., but also with software, for example, executed by various types of processors, or with a combination of the aforementioned hardware circuits and software (e.g., firmware).

[0099] It should be noted that the above description of the modules is for convenience only and should not be construed as limiting this specification to the embodiments described. It is understood that those skilled in the art, after understanding the principle of the device, may arbitrarily combine the modules or construct subsystems connected to other modules without departing from this principle. For example, the modules may share a single storage module, or each module may have its own separate storage module. Such modifications are all within the scope of this specification.

[0100] Figure 14 This is a schematic diagram of a computer system for implementing the determination method and / or screening method in one embodiment of this application. (Refer to...) Figure 14 The computer system S00 may include a processing component S20, which further includes one or more processors, and memory resources represented by memory S22 for storing instructions, such as application programs, that can be executed by the processors of the processing component S20. The application programs stored in memory S22 may include one or more instructions, with each module corresponding to a set of instructions. Furthermore, the processing component S20 is configured to execute instructions to perform the aforementioned determination and / or filtering methods.

[0101] The operations and / or methods described in the embodiments of this specification, implemented by a single processor, may also be implemented jointly or independently by multiple processors. For example, if, in this application specification, the processor of the processing device executes steps 100 to 400, it should be understood that steps 100 to 400 may also be executed jointly or independently by two different processors of the processing device (e.g., the first processor executes steps 100 to 300, the second processor executes step 400, or the first and second processors jointly execute steps 100 to 400).

[0102] The computer system S00 may further include: a power supply component S24 configured to perform power management of the computer system S00; a wired or wireless network interface S26 configured to connect the computer system S00 to a network; and an input / output (I / O) interface S28. The computer system S00 can operate on an operating system stored in memory S22, such as Windows Server, Mac OS X, Unix, Linux, FreeBSD, or similar.

[0103] In an exemplary embodiment, a computer-readable storage medium including instructions is also provided, such as a memory S22 including instructions, which can be executed by the processor of the computer system S00 to perform the above method. The storage medium can be a computer-readable storage medium, for example, a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc.

[0104] In an exemplary embodiment, a computer program product is also provided, the computer program product including instructions that can be executed by a processor of a computer system S00 to perform the above method.

[0105] In one embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 15 As shown, Figure 15 This is an internal structural diagram of a computer device according to one embodiment of this application. The computer device includes a processor, memory, and a network interface connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database stores user- and task-related data used in the methods described above. The network interface communicates with external terminals via a network connection. When the computer program is executed by the processor, it implements a determination method and / or a processing method.

[0106] Those skilled in the art will understand that Figure 15 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0107] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0108] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on its differences from other embodiments. In particular, hardware + program embodiments are basically similar to method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0109] It should be noted that the devices, electronic devices, servers, etc., described above according to the method embodiments may also include other implementation methods, and specific implementation methods can be referred to the description of the relevant method embodiments. Furthermore, new embodiments formed by the combination of features between various methods, devices, and server embodiments still fall within the scope of this application, and will not be elaborated upon here.

[0110] In the description of this specification, the references to "one embodiment," "an embodiment," and / or "some embodiments," "some embodiments," "other embodiments," "ideal embodiments," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiment or example, and certain features, structures, or characteristics in one or more embodiments of this specification may be appropriately combined.

[0111] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0112] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

[0113] The basic concepts have been described herein. It is obvious that the detailed disclosure above is merely illustrative and does not constitute a limitation of this specification. Although not explicitly stated herein, various modifications, improvements, and corrections may be made to this specification by those skilled in the art. Such modifications, improvements, and corrections are suggested in this specification and therefore remain within the spirit and scope of the exemplary embodiments described herein.

[0114] Furthermore, those skilled in the art will understand that various aspects of this specification can be described and illustrated in several patentable ways or situations, including any new and useful combination of processes, machines, products, or substances, or any new and useful improvements thereof. Accordingly, various aspects of this specification can be implemented entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. All of the above hardware or software may be referred to as a “data block,” “module,” “engine,” “module,” “component,” or “system.” Furthermore, various aspects of this specification may be represented as a computer product located on one or more computer-readable media, including computer-readable program code.

[0115] Computer storage media may contain a propagated data signal containing computer program code, for example, on baseband or as part of a carrier wave. This propagated signal may take various forms, including electromagnetic, optical, and suitable combinations thereof. Computer storage media can be any computer-readable medium other than a computer-readable storage medium, which can be connected to an instruction execution system, apparatus, or device to enable communication, propagation, or transmission of a program for use. The program code located on the computer storage medium can be propagated through any suitable medium, including radio, cable, fiber optic cable, RF, or similar media, or any combination of the above media.

[0116] The computer program code required for the operation of each part of this manual can be written in any one or more programming languages, including object-oriented programming languages ​​such as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C++, C#, VB.NET, Python, etc.; conventional procedural programming languages ​​such as C, Visual Basic, Fortran 3003, Perl, COBOL 3002, PHP, ABAP; dynamic programming languages ​​such as Python, Ruby, and Groovy; or other programming languages. This program code can run entirely on the user's computer, or as a standalone software package on the user's computer, or partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter case, the remote computer can be connected to the user's computer through any network, such as a local area network (LAN) or wide area network (WAN), or connected to an external computer (e.g., via the Internet), or in a cloud computing environment, or used as a service such as Software as a Service (SaaS).

[0117] Furthermore, unless expressly stated in the claims, the order of processing elements and sequences, the use of numbers and letters, or other names described in this specification are not intended to limit the order of the processes and methods described herein. Although various examples have been discussed in the foregoing disclosure of some embodiments of the invention that are currently considered useful, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments; rather, the claims are intended to cover all modifications and equivalent combinations that conform to the spirit and scope of the embodiments described herein. For example, while the system components described above can be implemented using hardware devices, they can also be implemented solely using software solutions, such as installing the described system on existing servers or mobile devices.

[0118] Similarly, it should be noted that, in order to simplify the description disclosed herein and thus aid in the understanding of one or more embodiments of the invention, the foregoing description of embodiments in this specification may sometimes combine multiple features into a single embodiment, drawing, or description thereof. However, this method of disclosure does not imply that the subject matter of this specification requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of a single embodiment disclosed above.

[0119] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of range in some embodiments of this specification are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

[0120] For each patent, patent application, patent application publication, and other material such as articles, books, specifications, publications, and documents referenced in this specification, the entire contents of which are incorporated herein by reference. This excludes historical application documents that are inconsistent with or conflict with the content of this specification, as well as documents that limit the broadest scope of the claims in this specification (currently or subsequently appended to this specification). It should be noted that in the event of any inconsistency or conflict between the descriptions, definitions, and / or terminology used in the supplementary materials to this specification and the content of this specification, the descriptions, definitions, and / or terminology used in this specification shall prevail.

[0121] Finally, it should be understood that the embodiments described in this specification are merely illustrative of the principles of the embodiments described herein. Other variations may also fall within the scope of this specification. Therefore, alternative configurations of the embodiments described herein are intended to be illustrative rather than limiting, and should be considered consistent with the teachings of this specification. Accordingly, the embodiments described herein are not limited to those explicitly introduced and described herein.

Claims

1. A method for determining an event region, characterized in that, include: Based on the location information of several events in the crystal strip or crystal array, determine the aggregation position of the non-scattering events and the location information of the scattering events corresponding to each crystal strip; The event regions of the corresponding crystal strips are divided based on the aggregation location of the non-scattering events and the location information of the scattering events.

2. The determination method according to claim 1, characterized in that, Before determining the aggregation location of the non-scattering events and the location information of the scattering events corresponding to each crystal strip, the determination method further includes: Several events are collected, and the position coordinates of each event on the crystal bar or crystal array are calculated using a predetermined position reconstruction algorithm. The positioning information is determined based on the position coordinates.

3. The determination method according to claim 1, characterized in that, Determine the clustering location of non-scattering events corresponding to each crystal strip, including: The location of the non-scattering events corresponding to each crystal strip is determined by local count maxima, or by combining local count maxima with the physical arrangement calibration of the crystal strips.

4. The determination method according to claim 1, characterized in that, Based on the location information of several events in a crystal strip or crystal array, the aggregation position of non-scattering events corresponding to each crystal strip is determined, including: The positioning information is formed into a two-dimensional location spectrum, and the clustered location is formed into a light spot on the two-dimensional location spectrum.

5. The determination method according to claim 1, characterized in that, Based on the location information of several events in the crystal strip or crystal array, the aggregation position of the non-scattering events corresponding to each crystal strip is determined, including: The location information is formed into a list of count data related to the coordinates of the corresponding event. The coordinates that meet the following conditions are combined into the clustered location: the coordinates are adjacent or the difference between the coordinates is less than a first preset value, and the corresponding count data is greater than a second preset value, or the coordinates are arranged in descending order at the first predetermined position.

6. The determination method according to claim 1, characterized in that, Based on the aggregation location of the non-scattering events and the location information of the scattering events, the event regions of the corresponding crystal strips are divided, including: A boundary is set around the gathering location, and the area within the boundary forms the event area.

7. The determination method according to claim 6, characterized in that, Based on the aggregation location of the non-scattering events and the location information of the scattering events, the event regions of the corresponding crystal strips are divided, including: The distance between each point on the boundary and the center of the corresponding aggregation location is correlated with the occurrence rate of intercrystalline scattering events at the location corresponding to the point.

8. The determination method according to claim 6, characterized in that, The distance between each point on the boundary and the center of the aggregation location is different.

9. The determination method according to claim 1, characterized in that, Based on the aggregation location of the non-scattering events and the location information of the scattering events, the event regions of the corresponding crystal strips are divided, including: The event regions of the corresponding crystal strips are divided based on the aggregation location of the non-scattering events, the location information of the scattering events, and the relative positions of the corresponding crystal strips with adjacent crystal strips.

10. The determination method according to claim 1, characterized in that, The shape of the event area can be any one of rectangle, irregular shape, circle or ellipse.

11. The determination method according to claim 1, characterized in that, The event regions corresponding to different crystal strips in the same crystal array may have the same shape, not exactly the same shape, or completely different shape.

12. The determination method according to claim 1, characterized in that, Based on the aggregation location of the non-scattering events and the location information of the scattering events, the event regions of the corresponding crystal strips are divided, including: Each crystal bar corresponds to one event region.

13. A method for processing intercrystalline scattering events, characterized in that, include: For each detected event, if the detected event is located within the event region as described in any one of claims 1 to 12, it is considered a valid event; otherwise, it is considered an intercrystalline scattering event and is discarded.

14. A device for determining an event region, characterized in that, include: The aggregation location determination unit is configured to determine the aggregation location of non-scattering events and the location information of scattering events corresponding to each crystal strip based on the positioning information of several events in the crystal strip or crystal array. The region determination unit is configured to divide the event region of the corresponding crystal strip based on the aggregation location of the non-scattering event and the location information of the scattering event.

15. The determining device according to claim 14, characterized in that, Also includes: The position spectrum determination unit is configured to collect several events and calculate the position coordinates of each event on the crystal strip or crystal array through a predetermined position reconstruction algorithm, and determine the positioning information based on the position coordinates of all events.

16. The determining device according to claim 14, characterized in that, The aggregation location determination unit is configured to determine the aggregation location of the scattering events corresponding to each crystal strip by means of local count maxima, or by means of a combination of local count maxima and crystal strip physical arrangement calibration.

17. The determining device according to claim 14, characterized in that, The aggregation location determination unit is configured to form the positioning information into a two-dimensional location spectrum and to form the aggregation location into a light spot on the two-dimensional location spectrum.

18. The determining device according to claim 14, characterized in that, The aggregation location determination unit is configured to form the positioning information into a list of count data related to the coordinates of the corresponding event, and to combine the coordinates that meet the following conditions: the coordinates are adjacent or the difference between the coordinates is less than a first preset value, and the corresponding count data is greater than a second preset value, or the coordinates are arranged in descending order at the first predetermined position as the aggregation location.

19. The determining device according to claim 14, characterized in that, The region determination unit is configured to set a boundary around the aggregation location, and the region within the boundary forms the event region.

20. The determining device according to claim 19, characterized in that, The region determination unit is configured to correlate the distance between each point on the boundary and the center of the corresponding aggregation location with the occurrence rate of intercrystalline scattering events at the location corresponding to the point.

21. The determining device according to claim 19, characterized in that, The distance between each point on the boundary and the center of the aggregation location is different.

22. The determining device according to claim 14, characterized in that, The region determination unit is configured to divide the event region of the corresponding crystal strip based on the aggregation location, the scattering event location information, and the relative position of the corresponding crystal strip with adjacent crystal strips.

23. The determining device according to claim 14, characterized in that, The shape of the event area can be any one of rectangle, irregular shape, circle or ellipse.

24. The determining device according to claim 14, characterized in that, The event regions corresponding to different crystal strips in the same crystal array may have the same shape, not exactly the same shape, or completely different shape.

25. The determining device according to claim 14, characterized in that, The region determination unit is configured to set one event region on each crystal strip.

26. A device for processing intercrystalline scattering events, characterized in that, The processing device is configured such that for each detected event, if the detected event is located within the event region as described in any one of claims 14 to 25, it is considered a valid event; otherwise, it is considered an intercrystalline scattering event and is discarded.

27. A computer storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the determining method according to any one of claims 1 to 12 and / or the processing method according to claim 13.

28. A computer program product, characterized in that, It includes a computer program or instructions, which, when executed by a processor, implements the steps of the determining method according to any one of claims 1 to 12 and / or the processing method according to claim 13.

Images