Instant gamma photon event identification method, data reconstruction method and electronic equipment

Abstract

The invention is suitable for the technical field of medical treatment, and provides an identification method of an instant gamma photon event, a data reconstruction method and electronic equipment. The identification method for the instant gamma photon event comprises the steps that first TOF data of a double-coincidence event detected by a detector are acquired, and the double-coincidence event is two associated events which occur at the same time; second TOF data of three coincidence events are determined according to the first TOF data, and the three coincidence events are three associated events occurring at the same time; performing one or more verification operations to determine a prompt gamma photon location; and determining an instant gamma photon event in the three coincidence events based on the instant gamma photon position. According to the embodiment of the invention, the instant gamma photon event can be effectively identified by using the TOF data, and double-nuclide signals can be separated.

Description

Technical Field

[0001] The present application belongs to the field of medical technology, and in particular relates to a method for identifying a prompt gamma photon event, a data reconstruction method and an electronic device. Background Art

[0002] Electron emission tomography (PET) is one of the current ultra-high sensitivity and specific in vivo molecular imaging methods, and has become an important tool for tumor research and clinical diagnosis and treatment. The principle of PET imaging is to use the positrons emitted by radionuclides during the decay process, which interact with electrons in the surrounding matter to produce annihilation radiation and emit two photons with opposite directions and equal energy. Based on these two photons, the tomographic distribution map of the body's positron nuclides is obtained to display the location, morphology, size and metabolic function of the lesion and diagnose the disease.

[0003] Traditional PET single scan imaging can only perform functional imaging of one tracer, and its ability to depict complex life activities is limited. PET multiple scan imaging can provide more comprehensive information on life activities, but the economic and time costs are high, and the registration problem between multiple scans will also affect the final imaging quality. Therefore, multi-tracer single PET scan imaging is of great significance in clinical applications.

[0004] However, some nuclides will emit prompt gamma photon rays (prompt-γ rays) with a certain probability while decaying, which can produce triple coincidence events after positron annihilation. However, in the traditional multi-tracer single PET scanning imaging process, only double coincidence events can be identified and output, and prompt gamma photon events (prompt-γ events) cannot be identified in triple coincidence events, which leads to the inability to effectively separate dual nuclide signals. Summary of the invention

[0005] The embodiments of the present application provide a method for identifying prompt gamma photon events, a data reconstruction method and an electronic device, which can effectively identify prompt gamma photon events using TOF data and help separate dual-nuclide signals.

[0006] A first aspect of an embodiment of the present application provides a method for identifying a prompt gamma photon event, comprising: acquiring first TOF data of a double coincidence event detected by a detector; the double coincidence event is two simultaneously occurring related events; determining second TOF data of a triple coincidence event based on the first TOF data; the triple coincidence event is three simultaneously occurring related events; performing one or more verification operations to determine the prompt gamma photon position; based on the prompt gamma photon position, determining the prompt gamma photon event in the triple coincidence event; the verification operation comprises: selecting a candidate true double coincidence event and a candidate prompt gamma photon position based on the triple coincidence event; acquiring a candidate decay position based on the detection position and TOF information of the candidate true double coincidence event; acquiring estimated TOF data of the triple coincidence event based on the candidate decay position; and determining the candidate prompt gamma photon position as the prompt gamma photon position in response to the estimated TOF data matching the second TOF data.

[0007] In some embodiments of the first aspect, the identification method further includes: determining a flight time error between the estimated TOF data and the second TOF data; if the flight time error is less than an error threshold, confirming that the estimated TOF data matches the second TOF data.

[0008] In some embodiments of the first aspect, determining the flight time error between the estimated TOF data and the second TOF data includes: determining a reference TOF vector based on the second TOF data; calculating the distance between the TOF vector corresponding to the estimated TOF data and the reference TOF vector to obtain the flight time error.

[0009] In some embodiments of the first aspect, the acquiring of the candidate decay position based on the detection position and TOF information of the candidate true double coincidence event comprises: according to the detection position and TOF information of the candidate true double coincidence event; and according to the weighted weights, performing weighted addition on the detection positions of the candidate true double coincidence events to obtain the candidate decay position.

[0010] In some embodiments of the first aspect, determining the weighted weight based on the detection position and TOF information of the candidate true double coincidence event includes: calculating the distance between the photon pairs corresponding to the candidate true double coincidence event based on the detection position of the candidate true double coincidence event; dividing the flight time corresponding to the TOF information by the distance between the photon pairs, and determining the weighted weight based on the division result and the speed of light.

[0011] In some embodiments of the first aspect, determining the second TOF data of three coincidence events based on the first TOF data includes: determining, based on the first TOF data, double coincidence events with the same detection position; and determining the second TOF data based on the double coincidence events with the same detection position.

[0012] In some embodiments of the first aspect, the events with the same detection position include three double-coincidence events, wherein there is one same detection position between every two double-coincidence events in the three double-coincidence events, and the same detection positions between every two double-coincidence events are different; determining the second TOF data based on the double-coincidence events with the same detection position includes: detecting whether the TOF information of the three double-coincidence events meets the time condition; if the TOF information of the three double-coincidence events meets the time condition, generating the second TOF data based on the detection positions and TOF information of the three double-coincidence events.

[0013] In some embodiments of the first aspect, the event with the same detection position includes two double-coincidence events; determining the second TOF data based on the double-coincidence events with the same detection position includes: determining the TOF information of a third double-coincidence event based on the TOF information of the two double-coincidence events; generating the second TOF data based on the detection positions and TOF information of the two double-coincidence events and the TOF information of the third double-coincidence event.

[0014] In an embodiment of the present application, by acquiring the first TOF data of a double coincidence event detected by a detector, determining the second TOF data of a triple coincidence event based on the first TOF data, performing one or more verification operations to determine the position of a prompt gamma photon, and based on the position of the prompt gamma photon, determining the prompt gamma photon event in the triple coincidence event, the TOF situation of the double coincidence event can be used to obtain the TOF data of the triple coincidence event, and the position of the prompt gamma photon can be verified by using the TOF situation of the triple coincidence event, so as to effectively identify the prompt gamma photon event in the triple coincidence event, which is helpful to separate the dual-nuclide signals.

[0015] A second aspect of an embodiment of the present application provides a PET data reconstruction method, comprising: acquiring first TOF data of a double coincidence event detected by a detector; the double coincidence event is two simultaneously occurring related events; determining second TOF data of a triple coincidence event based on the first TOF data; the triple coincidence event is three simultaneously occurring related events; performing one or more verification operations to determine a true double coincidence event; reconstructing the TOF data corresponding to the true double coincidence event to obtain a TOF image; the verification operation comprises: selecting a candidate true double coincidence event based on the triple coincidence event; acquiring a candidate decay position based on the detection position and TOF information of the candidate true double coincidence event; acquiring estimated TOF data of the triple coincidence event based on the candidate decay position; and determining the candidate true double coincidence event as a true double coincidence event in response to the estimated TOF data matching the second TOF data.

[0016] In the implementation manner of the present application, the TOF situation of the triple coincidence event can be used to determine the true double coincidence event, which facilitates reconstruction of the TOF data corresponding to the true double coincidence event to obtain the TOF image, thereby helping to improve the reliability of the TOF image.

[0017] A third aspect of an embodiment of the present application provides a device for identifying prompt gamma photon events, including: an acquisition unit, used to acquire first TOF data of a double coincidence event detected by a detector; the double coincidence event is two simultaneously occurring related events; a determination unit, used to determine second TOF data of a triple coincidence event based on the first TOF data; the triple coincidence event is three simultaneously occurring related events; a verification unit, used to perform one or more verification operations to determine the prompt gamma photon position; an identification unit, used to determine the prompt gamma photon event in the triple coincidence event based on the prompt gamma photon position; the verification unit is specifically used to: select candidate true double coincidence events and candidate prompt gamma photon positions based on the triple coincidence events; acquire candidate decay positions based on the detection positions and TOF information of the candidate true double coincidence events; acquire estimated TOF data of the triple coincidence event based on the candidate decay positions; and determine the candidate prompt gamma photon position as the prompt gamma photon position in response to the estimated TOF data matching the second TOF data.

[0018] A PET data reconstruction device provided in a fourth aspect of an embodiment of the present application includes: an acquisition unit, used to acquire first TOF data of a double coincidence event detected by a detector; the double coincidence event is two simultaneously occurring related events; a determination unit, used to determine second TOF data of a triple coincidence event based on the first TOF data; the triple coincidence event is three simultaneously occurring related events; a verification unit, used to perform one or more verification operations to determine a true double coincidence event; a reconstruction unit, used to reconstruct the TOF data corresponding to the true double coincidence event to acquire a TOF image; the verification unit is specifically used to: select a candidate true double coincidence event based on the triple coincidence event; acquire a candidate decay position based on the detection position and TOF information of the candidate true double coincidence event; acquire estimated TOF data of the triple coincidence event based on the candidate decay position; and determine the candidate true double coincidence event as a true double coincidence event in response to the estimated TOF data matching the second TOF data.

[0019] A fifth aspect of an embodiment of the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the following steps when executing the computer program: obtaining first TOF data of a double coincidence event detected by a detector; the double coincidence event is two simultaneously occurring related events; determining second TOF data of a triple coincidence event based on the first TOF data; the triple coincidence event is three simultaneously occurring related events; performing one or more verification operations to determine the prompt gamma photon position; determining the prompt gamma photon event based on the prompt gamma photon position, and deleting the TOF data corresponding to the prompt gamma photon event from the second TOF data; the verification operation comprises: selecting a candidate true double coincidence event and a candidate prompt gamma photon position based on the triple coincidence event; obtaining a candidate decay position based on the detection position and TOF information of the candidate true double coincidence event; obtaining estimated TOF data of the triple coincidence event based on the candidate decay position; determining the candidate prompt gamma photon position as the prompt gamma photon position in response to the estimated TOF data matching the second TOF data.

[0020] A sixth aspect of an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for identifying prompt gamma photon events are implemented, or when the computer program is executed by a processor, the steps of the method for reconstructing PET data are implemented.

[0021] A seventh aspect of an embodiment of the present application provides a computer program product. When the computer program product is run on an electronic device, the electronic device executes the steps of the above-mentioned method for identifying prompt gamma photon events, or the electronic device executes the steps of the above-mentioned method for reconstructing PET data.

[0022] It can be understood that the beneficial effects of the third to seventh aspects mentioned above can be found in the relevant descriptions of the first and second aspects mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 It is a schematic diagram of the implementation flow of the method for identifying prompt gamma photon events provided in an embodiment of the present application;

[0025] Figure 2 is a schematic diagram of a detector provided in an embodiment of the present application;

[0026] Figure 3 It is a schematic diagram of a specific implementation flow of the verification operation provided in the embodiment of the present application;

[0027] Figure 4 is a schematic diagram of a specific implementation flow of determining the second TOF data provided in an embodiment of the present application;

[0028] Figure 5 It is a schematic diagram of the implementation flow of the PET data reconstruction method provided in the embodiment of the present application;

[0029] Figure 6 It is a structural schematic diagram of a device for identifying prompt gamma photon events provided in an embodiment of the present application;

[0030] Figure 7 is a structural schematic diagram of a PET data reconstruction device provided in an embodiment of the present application;

[0031] Figure 8 It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work are protected by the present application.

[0033] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0034] In the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0035] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0036] Traditional PET single scan imaging can only perform functional imaging of one tracer, and its ability to depict complex life activities is limited. PET multiple scan imaging can provide more comprehensive information on life activities, but the economic and time costs are high, and the registration problem between multiple scans will also affect the final imaging quality. Therefore, multi-tracer single PET scan imaging is of great significance in clinical applications.

[0037] However, some nuclides will emit prompt gamma photon rays with a certain probability while decaying, which can produce triple coincidence events after positron annihilation. However, in the traditional multi-tracer single PET scanning imaging process, only double coincidence events can be identified and output, and prompt gamma photon events cannot be identified in triple coincidence events, which leads to the inability to effectively separate dual nuclide signals.

[0038] In view of this, the present application proposes a method for identifying prompt gamma photon events, which can use the flight time of double coincidence events to obtain TOF data of triple coincidence events, and use the TOF conditions of triple coincidence events to effectively identify prompt gamma photon events in triple coincidence events, which helps to separate dual-nuclide signals.

[0039] To facilitate understanding, some professional terms mentioned in this application are first explained.

[0040] Photon pair: A pair of photons flying in opposite directions produced when a particle annihilates an electron. + Photon pairs.

[0041] Coincidence event: A coincidence event detected by coincidence detection technology that occurs simultaneously is recorded as a coincidence count. A double coincidence event is two coincidence events that occur simultaneously. A triple coincidence event is three coincidence events that occur simultaneously. In the embodiments of the present application, a triple coincidence event may refer to a β + Double coincidence events produced by photon pairs and prompt gamma photon events produced by the simultaneous emission of prompt gamma photon rays during decay.

[0042] Prompt gamma photon event: also known as prompt-γ event, refers to the generation of a single gamma photon in addition to a pair of photons flying in opposite directions when annihilation occurs. Since the time difference between the gamma photon and the photon pair is only picoseconds (ps), the gamma photon is called prompt gamma photon (prompt-γ).

[0043] TOF: Time of Flight, in this application, refers to the time difference between a pair of photons reaching the PET detector, that is, the difference in detection time.

[0044] Detection position: The position where the detector receives the photon.

[0045] Decay Position: The location where the decay occurs.

[0046] In order to illustrate the technical solution of the present application, a specific embodiment is provided below for illustration.

[0047] Please refer to Figure 1 1 shows a schematic diagram of the implementation process of a method for identifying a prompt gamma photon event provided by an embodiment of the present application, which can be applied to an electronic device. The electronic device can be a computer, a PET device, or other intelligent device capable of processing TOF data, which is not limited by the present application.

[0048] Specifically, the method for identifying prompt gamma photon events may include the following steps S101 to S104.

[0049] Step S101, acquiring first TOF data of a double coincidence event detected by a detector.

[0050] In the embodiments of the present application, the detector may be a PET detector. The PET detector may be a ring structure formed by a plurality of detector units, and is used to capture photons generated when annihilation occurs. The electronic device may obtain the first TOF data collected by the detector within a period of time by wired or wireless communication with the PET detector.

[0051] A double coincidence event is two related events that occur simultaneously. The first TOF data of a double coincidence event is data that carries the flight time between the double coincidence events, generated based on the detection results of the detector for the double coincidence event. The first TOF data may include the detection position and TOF information of the double coincidence event, and may be queued in a list (list-mode). e Specifically, the first TOF data can be expressed as (p1, p2, t 12 ). Where p1 and p2 are the detection positions of photons. 12 It is the difference between the detection times of p1 and p2, that is, the flight time of events p1 and p2.

[0052] In the implementation of this application, please refer to Figure 2 , since some nuclides will emit prompt gamma photon rays with a certain probability when they decay ( Figure 2 The double coincidence events detected by the detector may include double coincidence events generated by photon pairs (or true double coincidence events), or may include double coincidence events consisting of a prompt gamma photon event and an event corresponding to one photon in the photon pair (or false double coincidence events).

[0053] Step S102: determining second TOF data of three coincident events according to the first TOF data.

[0054] In the implementation of the present application, the three coincidence events are three simultaneously occurring related events, which may refer to the double coincidence events generated by the photon pair and the prompt gamma photon event generated by the decay and the emission of prompt gamma photon rays, and the flight times of the three events are temporally correlated. The second TOF data of the three coincidence events carries the TOF information between the three coincidence events, and may include the detection positions of the three events of the three coincidence events, and the flight times between the three events.

[0055] Specifically, a triple coincidence event has three photons, so the second TOF data can be expressed as:

[0056] {(p1, p2, t 12 ), (p1, p3, t 13), (p2, p3, t 23 )}.

[0057] Among them, p1, p2, and p3 represent the detection positions of three photons, corresponding to the true double coincidence event generated by the photon pair, and a prompt gamma photon event. 12 is the difference between the detection times of p1 and p2, t 13 is the difference between the detection times of p1 and p3, t 23 is the difference between the detection times of p2 and p3. According to the definition of flight time, t 23 =t 13 -t 12 Based on this correlation in flight time, the second TOF data of the three coincident events can be determined according to the first TOF data.

[0058] Step S103, performing one or more verification operations to determine the prompt gamma photon position.

[0059] In the implementation of the present application, after obtaining the second TOF data, one or more verification operations may be performed based on the detection positions of the three photons and the TOF information between each of them to determine the prompt gamma photon position, wherein the prompt gamma photon position refers to the detection position of the prompt gamma photon.

[0060] In the implementation mode of the present application, Figure 3 As shown, the verification operation may include steps S301 to S304.

[0061] Step S301, selecting candidate true double coincidence events and candidate prompt gamma photon positions based on triple coincidence events.

[0062] In the embodiments of the present application, a true double coincidence event refers to a coincidence event in which the two photons detected coincidentally originate from the same annihilation event and neither of the two photons interacts with the medium before reaching the detector. Of the three detection positions of a triple coincidence event, one must correspond to a prompt gamma photon, and the other two correspond to a photon pair with an angle of π generated by the annihilation of positrons and electrons. 12 ), (p1, p3, t 13 ), (p2, p3, t 23 )}, it is known that it is the TOF data of a triple coincidence event, but it is unknown which of p1, p2, and p3 corresponds to a prompt gamma photon event. Therefore, one of the three coincidence events can be selected as a prompt gamma photon event, and its corresponding detection position is the candidate prompt gamma photon position; at this time, the remaining two events are selected as candidate true double coincidence events.

[0063] For example, if p1 is selected as the candidate prompt gamma photon position, then p2 and p3 correspond to a candidate true double coincidence event. If p2 is selected as the candidate prompt gamma photon position, then p1 and p3 correspond to a candidate true double coincidence event. If p3 is selected as the candidate prompt gamma photon position, then p1 and p2 correspond to a candidate true double coincidence event.

[0064] Step S302: Acquire a candidate decay position based on the detection position and TOF information of the candidate true double coincidence event.

[0065] Based on the detection position and TOF information of the candidate true double coincidence event, the decay occurrence position corresponding to the candidate true double coincidence event can be determined and used as the candidate decay position.

[0066] Specifically, step S302 may include: determining weighted weights according to the detection positions and TOF information of the candidate true double coincidence events, and performing weighted addition on the detection positions of the candidate true double coincidence events according to the weighted weights to obtain the candidate decay positions.

[0067] Among them, determining the weighted weight based on the detection position and TOF information of the candidate true double coincidence event can include: calculating the distance between the photon pairs corresponding to the candidate true double coincidence event based on the detection position of the candidate true double coincidence event, dividing the flight time corresponding to the TOF information by the distance between the photon pairs, and determining the weighted weight based on the division result and the speed of light.

[0068] Take p1, p2, and p3 as candidate prompt gamma photon positions and discuss them in categories. Define c as the speed of light, ":=" as the assignment symbol, and "||ab||" as the distance between a and b.

[0069] Let p1 be the candidate prompt gamma photon position. At this time, the true double coincidence event generated by the photon pair is (p2, p3, t 23 ), the candidate decay position p can be calculated 23 : =λp2+(1-λ)p3, where weighted weight λ: =(1-c·t 23 / ||p2-p3||) / 2.

[0070] Let p2 be the candidate prompt gamma photon position. At this time, the true double coincidence event generated by the photon pair is (p1, p3, t 13 ), the candidate decay position p can be calculated 13 : =λp1+(1-λ)p3, where the weighted weight λ: =(1-c·t 13 / ||p1-p3||) / 2.

[0071] Let p3 be the candidate prompt gamma photon position. At this time, the true double coincidence event generated by the photon pair is (p1, p2, t 12), the candidate decay position p can be calculated 12 : =λp1+(1-λ)p2, where weighted weight λ: =(1-c·t 12 / ||p1-p2||) / 2.

[0072] Step S303: acquiring estimated TOF data of three coincidence events based on the candidate decay positions.

[0073] The estimated TOF data may include the TOF information between every two events in the three coincident events, which can be expressed as (t′ 12 , t′ 13 , t′ 23 Specifically, for the candidate decay position, substitute the second TOF data {(p1, p2, t 12 ), (p1, p3, t 13 ), (p2, p3, t 23 )} can generate a corresponding estimated TOF data (t′ 12 , t′ 13 ′, t′ 23 ).

[0074] Step S304: in response to the estimated TOF data matching the second TOF data, determining the candidate prompt gamma photon position as the prompt gamma photon position.

[0075] If the estimated TOF data matches the second TOF data, it means that the candidate true double coincidence event and the candidate prompt gamma photon position selected by the estimated TOF data are consistent with the actual detection results, so the candidate prompt gamma photon position can be determined as the prompt gamma photon position. If the estimated TOF data does not match the second TOF data, it means that the candidate true double coincidence event and the candidate prompt gamma photon position selected by the estimated TOF data are inconsistent with the actual detection results, and the assumptions of the candidate true double coincidence event and the candidate prompt gamma photon position need to be abandoned.

[0076] Specifically, during the verification process, the identification method provided by the present application may also include: determining the flight time error between the estimated TOF data and the second TOF data; if the flight time error is less than the error threshold, confirming that the estimated TOF data matches the second TOF data.

[0077] In an embodiment of the present application, the smaller the time-of-flight error, the closer the candidate decay position is to the decay position corresponding to the true double coincidence event. If the time-of-flight error is less than the error threshold, it can be confirmed that the estimated TOF data matches the second TOF data. If the time-of-flight error is greater than or equal to the error threshold, it can be confirmed that the estimated TOF data does not match the second TOF data.

[0078] Specifically, a reference TOF vector may be determined according to the second TOF data, and a distance between a TOF vector corresponding to the estimated TOF data and the reference TOF vector may be calculated to obtain a time of flight error.

[0079] The reference TOF vector represents the true value of the TOF vector of the three coincident events. 12 ), (p1, p3, t 13 ), (p2, p3, t 23 )}, the reference TOF vector (t 12 , t 13 , t 23 Based on the estimated TOF data, the corresponding TOF vector (t′) can be obtained. 12 , t′ 13 , t′ 23 ). The distance dist((t 12 , t 13 , t 23 ), (t′ 12 , t′ 13 , t′ 23 )), the flight time error can be obtained. Wherein, dist is a distance function, which can be a Euclidean distance function, a Manhattan distance function, etc., and this application does not limit this.

[0080] As can be understood, the distance is positively correlated with the amount of flight time error.

[0081] In the implementation of the present application, p1, p2, and p3 are respectively used as prompt gamma photon events, and three combinations of candidate true double coincidence events and candidate prompt gamma photon positions can be obtained. The present application can verify each combination; or verify each combination one by one until the prompt gamma photon position is obtained. In this case, the prompt gamma photon position can be obtained through at least one verification.

[0082] For example, assume that three matching event data satisfy p1: = (1, 0), p2: = (0, 1), p3: = (0, 0), and refer to the TOF vector (t 12 , t 13 , t 23 ):=(0,0,0), then according to the classification discussion, we can get:

[0083] Assume that p1 corresponds to a prompt gamma photon event, and the candidate decay position p 23 :=(0,0.5), the corresponding TOF vector is Does not match the reference TOF vector.

[0084] Assume that p2 corresponds to a prompt gamma photon event, and the candidate decay position p 13 :=(0.5,0), the corresponding TOF vector is Does not match the reference TOF vector.

[0085] Assume that p3 corresponds to a prompt gamma photon event. At this time, the candidate decay position p 12 :=(0.5,0.5), the corresponding TOF vector is (t′ 12 , t′ 13 , t′ 23 )=(0, 0, 0), and the distance from the reference TOF vector is 0 (ie, consistent).

[0086] So we can judge that p 12 is the decay position of the true double coincidence event, and p3 is the prompt gamma photon position.

[0087] Step S104, based on the prompt gamma photon position, determine the prompt gamma photon event among the three coincidence events.

[0088] In the implementation manner of the present application, an event in which the detection position is the prompt gamma photon position among the three coincidence events is a prompt gamma photon event.

[0089] In an embodiment of the present application, by acquiring the first TOF data of a double coincidence event detected by a detector, determining the second TOF data of a triple coincidence event based on the first TOF data, performing one or more verification operations to determine the position of a prompt gamma photon, and based on the position of the prompt gamma photon, determining the prompt gamma photon event in the triple coincidence event, the TOF situation of the double coincidence event can be used to obtain the TOF data of the triple coincidence event, and the position of the prompt gamma photon can be verified by using the TOF situation of the triple coincidence event, so as to effectively identify the prompt gamma photon event in the triple coincidence event, which is helpful to separate the dual-nuclide signals.

[0090] like Figure 4 As shown, in some embodiments of the present application, determining the second TOF data of three coincidence events according to the first TOF data may include steps S401 to S402.

[0091] Step S401: determining, based on the first TOF data, whether there are double coincidence events at the same detection position.

[0092] It is understandable that if there is an event corresponding to the same photon in two different double coincidence events, then the detection positions of the two events should be the same. For a triple coincidence event, there must be an event corresponding to the same photon between two double coincidence events. Based on this principle, according to the detection position in the first TOF data, it can be determined that there are double coincidence events with the same detection position. For example, the first TOF data (p1, p2, t 12 ) and the first TOF data (p1, p3, t 13 ) represents two different double coincidence events, and the detection position p1 is the same, which means that the two double coincidence events are double coincidence events with the same detection position, and there is an event corresponding to the same photon between the two double coincidence events (i.e., the event corresponding to p1).

[0093] By comparing the detection positions of the first TOF data of all double coincidence events in pairs, at least one pair of double coincidence events with the same detection position can be obtained.

[0094] Step S402: determining second TOF data according to the double coincidence events with the same detection position.

[0095] In the embodiment of the present application, for a pair of double coincidence events with the same detection position, the same detection position may correspond to one event, and the two different detection positions may each correspond to one event, so that the second TOF data of the three coincidence events can be determined. 12 ) and the first TOF data (p1, p3, t 13 ), the detection position p1 is the same, p1 can correspond to the same event, and p2 and p3 can each correspond to an event.

[0096] Specifically, this application provides two methods for acquiring the second TOF data:

[0097] Method 1:

[0098] The above-mentioned events with the same detection position include three double coincidence events, in which there is a same detection position between every two double coincidence events, and the same detection positions between every two double coincidence events are different.

[0099] For example, (p1, p2, t 12 )、(p1,p3,t 13 )、(p2,p3,t 23 ) represents the three double coincidence events mentioned above. (p1, p2, t 12 )、(p1,p3,t 13 ) between the same detection positions are p1, (p1, p2, t 12)、(p2,p3,t 23 ) between the same detection position is p2, (p1, p3, t 13 )、(p2,p3,t 23 ) is the same detection position between the two.

[0100] At this time, determining the second TOF data based on the existence of double coincidence events with the same detection position can include: detecting whether the TOF information of the three double coincidence events meets the time condition; if the TOF information of the three double coincidence events meets the time condition, generating the second TOF data based on the detection positions and TOF information of the three double coincidence events.

[0101] As explained above, the time condition that the TOF information of the three matching events should meet can be expressed as: t 23 =t 13 -t 12 .

[0102] If the TOF information of the three double coincidence events meets the time condition, it means that the three double coincidence events are true double coincidence events and prompt gamma photon events generated by the photon pairs. At this time, the detection positions p1, p2, p3 and TOF information t 12 ,t 13 ,t 23 , generate the second TOF data {(p1, p2, t 12 ), (p1, p3, t 13 ), (p2, p3, t 23 )}.

[0103] If the TOF information of the three double coincidence events does not meet the time condition, it means that the three double coincidence events are not true double coincidence events generated by photon pairs and prompt gamma photon events generated by the simultaneous decay and emission of prompt gamma photon rays. At this time, the three double coincidence events can be skipped.

[0104] Method 1 can screen out double coincidence events with the same detection position and satisfying the time condition from the collected first TOF data, and then generate second TOF data of triple coincidence events, which can ensure the accuracy of the second TOF data of triple coincidence events.

[0105] Method 2:

[0106] The above-mentioned event of having the same detection position includes two double coincidence events. For example, the two double coincidence events can be {(p1, p2, t 12 ), (p1, p3, t 13 )}、{(p2,p3,t 23 ), (p1, p3, t 13)}, or, {(p2, p3, t 23 ), (p2, p3, t 23 )}.

[0107] At this time, determining the second TOF data based on the double coincidence events with the same detection position may include: determining the TOF information of the third double coincidence event based on the TOF information of the two double coincidence events; generating the second TOF data based on the detection positions and TOF information of the two double coincidence events, and the TOF information of the third double coincidence event.

[0108] Specifically, according to t 23 =t 13 -t 12 The time relationship of the two double coincidence events can determine the TOF information of the third double coincidence event. At this time, the detection positions of the two double coincidence events can include the detection positions p1, p2, p3 and the TOF information between the two double coincidence events. Combined with the TOF information of the third double coincidence event, the second TOF data {(p1, p2, t 12 ), (p1, p3, t 13 ), (p2, p3, t 23 )}.

[0109] The two double coincidence events are {(p1, p2, t 12 ), (p1, p3, t 13 )}, the third double matching event can be obtained by (p2, p3, t 23 :=t 13 -t 23 ) for calculation.

[0110] This method can supplement the TOF information of the third double coincidence event when the third double coincidence event is missing, and then generate the second TOF data, which can improve the universality of the algorithm.

[0111] In some embodiments of the present application, after obtaining the prompt gamma photon event, the method may further include: removing the prompt gamma photon event from the three coincidence events to obtain a true double coincidence event. Alternatively, the TOF data corresponding to the prompt gamma photon event is deleted from the second TOF data. For example, when determining p 12 is the target decay position, p3 is the prompt gamma photon event, and the true double coincidence event can be determined as (p1, p2, t 12 ), delete (p1, p3, t 13 ) and (p2, p3, t 23 ).

[0112] True double coincidence events may be used for dual-nuclide imaging, image quality determination, or detector performance determination. This application does not impose any restrictions on the application scenarios of true double coincidence events.

[0113] Please refer to Figure 5 , Figure 5 The present invention provides a schematic diagram of a PET data reconstruction method according to an embodiment of the present invention, which can be applied to an electronic device. The electronic device can be a computer, a PET device, or other intelligent device capable of PET data reconstruction, which is not limited by the present invention.

[0114] The PET data reconstruction method may include: step S501 to step S504.

[0115] Step S501, acquiring first TOF data of a double coincidence event detected by a detector.

[0116] A double coincidence event is two related events that occur at the same time.

[0117] Step S502: Determine second TOF data of three coincident events according to the first TOF data.

[0118] Triple events are three related events that occur simultaneously.

[0119] Step S503, performing one or more verification operations to determine a true double coincidence event.

[0120] Among them, the verification operation may include: selecting a candidate true double coincidence event based on the three coincidence events; obtaining a candidate decay position based on the detection position and TOF information of the candidate true double coincidence event; obtaining estimated TOF data of the three coincidence events based on the candidate decay position; in response to the estimated TOF data matching the second TOF data, determining the candidate true double coincidence event as a true double coincidence event.

[0121] The specific implementation of steps S501 to S503 can be found in Figures 1 to 4 The difference is: Figure 1-4 In order to determine the candidate prompt gamma photon position as the prompt gamma photon position, Figure 5 To determine the candidate true double coincidence event as a true double coincidence event, that is, Figure 5 The focus is on identifying true double coincidence events among triple coincidence events, which will not be elaborated in this application.

[0122] Step S504, reconstructing the TOF data corresponding to the true double coincidence event to obtain a TOF image.

[0123] The TOF data may be TOF-PET data, and the TOF image may be a TOF-PET image. Based on the TOF data corresponding to the true double coincidence event, an existing method may be used to perform image reconstruction to obtain a TOF image.

[0124] In the implementation manner of the present application, the TOF situation of the triple coincidence event can be used to determine the true double coincidence event, which facilitates reconstruction of the TOF data corresponding to the true double coincidence event to obtain the TOF image, thereby helping to improve the reliability of the TOF image.

[0125] It should be noted that, for the sake of simplicity of description, the aforementioned method embodiments are all expressed as a series of action combinations, but those skilled in the art should know that the present application is not limited to the described order of actions, because according to the present application, certain steps can be performed in other orders.

[0126] like Figure 6 FIG. 6 is a schematic diagram of the structure of a device 600 for identifying a prompt gamma photon event provided in an embodiment of the present application. The device 600 for identifying a prompt gamma photon event is configured on an electronic device.

[0127] Specifically, the prompt gamma photon event recognition device 600 may include:

[0128] An acquisition unit 601 is used to acquire first TOF data of a double coincidence event detected by the detector; the double coincidence event is two associated events occurring simultaneously;

[0129] A determination unit 602 is configured to determine second TOF data of three matching events according to the first TOF data; the three matching events are three related events occurring simultaneously;

[0130] A verification unit 603, configured to perform one or more verification operations to determine the prompt gamma photon position;

[0131] An identification unit 604, configured to determine a prompt gamma photon event among the three coincidence events based on the prompt gamma photon position;

[0132] Among them, the verification unit 603 is specifically used to: select candidate true double coincidence events and candidate prompt gamma photon positions based on the three coincidence events; obtain candidate decay positions based on the detection positions and TOF information of the candidate true double coincidence events; obtain estimated TOF data of the three coincidence events based on the candidate decay positions; in response to the estimated TOF data matching the second TOF data, determine the candidate prompt gamma photon position as the prompt gamma photon position.

[0133] In some embodiments of the present application, the verification unit 603 may be specifically used to: determine the flight time error between the estimated TOF data and the second TOF data; if the flight time error is less than an error threshold, confirm that the estimated TOF data matches the second TOF data.

[0134] In some embodiments of the present application, the verification unit 603 may be specifically used to: determine a reference TOF vector based on the second TOF data; calculate the distance between the TOF vector corresponding to the estimated TOF data and the reference TOF vector to obtain the flight time error.

[0135] In some embodiments of the present application, the verification unit 603 may be specifically used to: determine a weighted weight based on the detection position and TOF information of the candidate true double coincidence event; and perform weighted addition on the detection positions of the candidate true double coincidence events based on the weighted weight to obtain the candidate decay position.

[0136] In some embodiments of the present application, the verification unit 603 can be specifically used to: calculate the distance between the photon pairs corresponding to the candidate true double coincidence event based on the detection position of the candidate true double coincidence event; divide the flight time corresponding to the TOF information by the distance between the photon pairs, and determine the weighted weight based on the division result and the speed of light.

[0137] In some embodiments of the present application, the determination unit 602 may be specifically configured to: determine the existence of a double coincidence event at the same detection position according to the first TOF data; and determine the second TOF data according to the double coincidence event at the same detection position.

[0138] In some embodiments of the present application, events with the same detection position include three double-coincidence events, wherein there is one same detection position between every two double-coincidence events in the three double-coincidence events, and the same detection positions between every two double-coincidence events are different; the determination unit 602 can be specifically used to: detect whether the TOF information of the three double-coincidence events meets the time condition; if the TOF information of the three double-coincidence events meets the time condition, then generate the second TOF data according to the detection positions and TOF information of the three double-coincidence events.

[0139] In some embodiments of the present application, events with the same detection position include two double-coincidence events; the determination unit 602 can be specifically used to: determine the TOF information of the third double-coincidence event based on the TOF information of the two double-coincidence events; generate the second TOF data based on the detection positions and TOF information of the two double-coincidence events, and the TOF information of the third double-coincidence event.

[0140] It should be noted that, for the convenience and simplicity of description, the specific working process of the above-mentioned prompt gamma photon event identification device 600 can refer to Figures 1 to 4 The corresponding process of the method will not be repeated here.

[0141] like Figure 7 FIG. 7 is a schematic structural diagram of a PET data reconstruction device 700 provided in an embodiment of the present application. The PET data reconstruction device 700 is configured on an electronic device.

[0142] Specifically, the PET data reconstruction device 700 may include:

[0143] An acquisition unit 701 is used to acquire first TOF data of a double coincidence event detected by the detector; the double coincidence event is two associated events occurring simultaneously;

[0144] A determination unit 702 is configured to determine second TOF data of three matching events according to the first TOF data; the three matching events are three related events occurring simultaneously;

[0145] A verification unit 703, configured to perform one or more verification operations to determine a true double coincidence event;

[0146] A reconstruction unit 704, configured to reconstruct the TOF data corresponding to the true double coincidence event to obtain a TOF image;

[0147] The verification unit 703 is specifically used to: select a candidate true double coincidence event based on the three coincidence events; obtain a candidate decay position based on the detection position and TOF information of the candidate true double coincidence event; obtain estimated TOF data of the three coincidence events based on the candidate decay position; and determine the candidate true double coincidence event as a true double coincidence event in response to the estimated TOF data matching the second TOF data.

[0148] It should be noted that, for the convenience and simplicity of description, the specific working process of the above-mentioned PET data reconstruction device 700 can be referred to Figure 5 The corresponding process of the method will not be repeated here.

[0149] like Figure 8, which is a schematic diagram of an electronic device 8 provided in an embodiment of the present application. Specifically, the electronic device 8 may include: a processor 80, a memory 81, and a computer program 82 stored in the memory 81 and executable on the processor 80. When the processor 80 executes the computer program 82, the following steps are implemented: obtaining the first TOF data of a double coincidence event detected by the detector; the double coincidence event is two simultaneously occurring related events; determining the second TOF data of a triple coincidence event based on the first TOF data; the triple coincidence event is three simultaneously occurring related events; performing one or more verification operations to determine the prompt gamma photon position; determining the prompt gamma photon event based on the prompt gamma photon position, and deleting the TOF data corresponding to the prompt gamma photon event from the second TOF data; the verification operation includes: selecting candidate true double coincidence events and candidate prompt gamma photon positions based on the triple coincidence events; obtaining candidate decay positions based on the detection positions and TOF information of the candidate true double coincidence events; obtaining estimated TOF data of the triple coincidence event based on the candidate decay positions; and determining the candidate prompt gamma photon position as the prompt gamma photon position in response to the estimated TOF data matching the second TOF data.

[0150] Among them, the method of determining the prompt gamma photon event based on the prompt gamma photon position can refer to Figure 1-4 When processing TOF data, the electronic device 8 may delete the TOF data corresponding to the prompt gamma photon event from the second TOF data, thereby deleting the non-true double coincidence data.

[0151] In this way, the remaining data in the second TOF data can represent data of true double coincidence events, which is convenient for data analysis and PET data reconstruction.

[0152] The computer program may be divided into one or more modules / units, which are stored in the memory 81 and executed by the processor 80 to complete the present application. The one or more modules / units may be a series of computer program instruction segments capable of completing specific functions, which are used to describe the execution process of the computer program in the electronic device 8.

[0153] The electronic device 8 may include, but is not limited to, a processor 80 and a memory 81. Those skilled in the art will appreciate that Figure 8 It is only an example of the electronic device 8 and does not constitute a limitation of the electronic device 8. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the electronic device 8 may also include input and output devices, network access devices, buses, etc.

[0154] The processor 80 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), off-the-shelf programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0155] The memory 81 may be an internal storage unit of the electronic device 8, such as a hard disk or memory of the electronic device 8. The memory 81 may also be an external storage device of the electronic device 8, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 8. Further, the memory 81 may also include both an internal storage unit of the electronic device 8 and an external storage device. The memory 81 is used to store the computer program and other programs and data required by the electronic device 8. The memory 81 may also be used to temporarily store data that has been output or is to be output.

[0156] It should be noted that, for the convenience and brevity of description, the structure of the electronic device 8 can also refer to the specific description of the structure in the method embodiment, which will not be repeated here.

[0157] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0158] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0159] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0160] In the embodiments provided in the present application, it should be understood that the disclosed devices / equipment and methods can be implemented in other ways. For example, the device / equipment embodiments described above are merely schematic, for example, the division of the modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0161] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0162] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0163] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0164] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for identifying prompt gamma photon events, characterized in that: include: Acquire first TOF data of a double coincidence event detected by the detector; the double coincidence event is two associated events occurring simultaneously; Determine second TOF data of three coincident events according to the first TOF data; the three coincident events are three associated events occurring simultaneously; performing one or more verification operations to determine the prompt gamma photon position; Based on the prompt gamma photon position, determining a prompt gamma photon event among the three coincidence events; The verification operation includes: Selecting a candidate true double coincidence event and a candidate prompt gamma photon position based on the triple coincidence event; Acquire a candidate decay position based on the detection position and TOF information of the candidate true double coincidence event; Based on the candidate decay positions, acquiring estimated TOF data of the three coincidence events; In response to the estimated TOF data matching the second TOF data, the candidate prompt gamma photon position is determined as the prompt gamma photon position.

2. The method for identifying prompt gamma photon events according to claim 1, characterized in that: The identification method further comprises: determining an amount of time of flight error between the estimated TOF data and the second TOF data; If the flight time error is less than an error threshold, it is confirmed that the estimated TOF data matches the second TOF data.

3. The method for identifying prompt gamma photon events as claimed in claim 2, characterized in that: Determining an amount of time-of-flight error between the estimated TOF data and the second TOF data comprises: Determine a reference TOF vector according to the second TOF data; The distance between the TOF vector corresponding to the estimated TOF data and the reference TOF vector is calculated to obtain the time of flight error.

4. The method for identifying prompt gamma photon events according to claim 1, characterized in that: The step of acquiring a candidate decay position based on the detection position and TOF information of the candidate true double coincidence event comprises: Determining a weighted weight according to the detection position and TOF information of the candidate true double coincidence event; According to the weighted weights, weighted addition is performed on the detection positions of the candidate true double coincidence events to obtain the candidate decay positions.

5. The method for identifying prompt gamma photon events as claimed in claim 4, characterized in that: The step of determining a weighted weight according to the detection position and TOF information of the candidate true double coincidence event comprises: Calculating the distance between the photon pairs corresponding to the candidate true double coincidence event according to the detection position of the candidate true double coincidence event; The flight time corresponding to the TOF information is divided by the distance between the photon pairs, and a weighted weight is determined according to the division result and the speed of light.

6. The method for identifying prompt gamma photon events according to any one of claims 1 to 5, characterized in that: Determining second TOF data of three matching events according to the first TOF data includes: Determining, based on the first TOF data, that there are double coincidence events at the same detection position; The second TOF data is determined according to the double coincidence events with the same detection position.

7. The method for identifying prompt gamma photon events according to claim 6, characterized in that: The event with the same detection position includes three double coincidence events, wherein one same detection position exists between every two double coincidence events in the three double coincidence events, and the same detection positions between every two double coincidence events are different; The determining the second TOF data according to the double coincidence events having the same detection position comprises: Detecting whether the TOF information of the three double coincidence events meets the time condition; If the TOF information of the three double coincidence events meets the time condition, the second TOF data is generated according to the detection positions and TOF information of the three double coincidence events.

8. The method for identifying prompt gamma photon events according to claim 6, characterized in that: The event of having the same detection position includes two double coincidence events; The determining the second TOF data according to the double coincidence events having the same detection position comprises: Determining TOF information of a third double coincidence event based on the TOF information of the two double coincidence events; The second TOF data is generated according to the detection positions and TOF information of the two double coincidence events and the TOF information of the third double coincidence event.

9. A PET data reconstruction method, characterized in that: include: Acquire first TOF data of a double coincidence event detected by the detector; the double coincidence event is two associated events occurring simultaneously; Determine second TOF data of three coincident events according to the first TOF data; the three coincident events are three associated events occurring simultaneously; performing one or more verification operations to determine a true double match event; Reconstructing TOF data corresponding to the true double coincidence event to obtain a TOF image; The verification operation includes: selecting a candidate true double coincidence event based on the three coincidence events; Acquire a candidate decay position based on the detection position and TOF information of the candidate true double coincidence event; Based on the candidate decay positions, acquiring estimated TOF data of the three coincidence events; In response to the estimated TOF data matching the second TOF data, the candidate true double coincidence event is determined to be a true double coincidence event.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the following steps are implemented: Acquire first TOF data of a double coincidence event detected by the detector; the double coincidence event is two associated events occurring simultaneously; Determine second TOF data of three coincident events according to the first TOF data; the three coincident events are three associated events occurring simultaneously; performing one or more verification operations to determine the prompt gamma photon position; Determining a prompt gamma photon event based on the prompt gamma photon position, and deleting TOF data corresponding to the prompt gamma photon event from the second TOF data; The verification operation includes: Selecting a candidate true double coincidence event and a candidate prompt gamma photon position based on the triple coincidence event; Acquire a candidate decay position based on the detection position and TOF information of the candidate true double coincidence event; Based on the candidate decay positions, acquiring estimated TOF data of the three coincidence events; In response to the estimated TOF data matching the second TOF data, the candidate prompt gamma photon position is determined as the prompt gamma photon position.

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