DOI Automatic Calibration Method and Device for a Dual-End PET Detector

Abstract

The present application is applicable to the field of scanning imaging technology, and provides a method and device for automatically calibrating the DOI of a dual-ended PET detector. The method includes: collecting energy data through the dual-ended PET detector, determining the distribution relationship between the DOI ratio and the number of gamma events based on the energy data to obtain a DOI curve, performing equal-area segmentation processing on the DOI curve to obtain multiple DOI boundary values, thereby calibrating the DOI scale table, and when a gamma event is detected, looking up the DOI corresponding to the gamma event through the DOI scale table. The present application realizes that when a gamma event is detected, the corresponding DOI can be automatically found through the DOI scale table, and at the same time, automatic calibration for DOI curves of different shapes can be achieved, with a small amount of calculation, improving the calibration accuracy and efficiency.

Description

Technical Field

[0001] This application belongs to the field of scanning imaging technology, and particularly relates to a method and device for automatically calibrating the DOI of a dual-ended PET detector. Background Art

[0002] Positron Emission Tomography (PET) is a molecular imaging technology with high sensitivity and is currently often used in fields such as tumor imaging and brain science disease research. In a PET imaging system, the inability to quickly and accurately determine the Depth Of Interaction (DOI) is a major factor hindering the simultaneous achievement of uniform high spatial resolution and high efficiency. A PET detector based on dual-ended readout can provide continuous depth information while providing high depth resolution, helping the PET imaging system achieve imaging results with uniform high spatial resolution and high efficiency.

[0003] Currently, there are mainly two methods for determining the depth of interaction based on a dual-ended PET detector; among them, the method of manually determining the depth of interaction based on a dual-ended PET detector usually requires a large number of crystals, with high difficulty and large workload, while the traditional automatic calibration method for the depth of interaction based on a dual-ended PET detector is usually only applicable to detectors with relatively regular DOI curves and has poor applicability. Summary of the Invention

[0004] The embodiments of this application provide a method, device, processing terminal, and readable storage medium for automatically calibrating the DOI of a dual-ended PET detector, which can solve the problems of high difficulty, large workload, and poor applicability of the traditional automatic calibration method for the depth of interaction based on a dual-ended PET detector.

[0005] In a first aspect, the embodiments of this application provide a method for automatically calibrating the DOI of a dual-ended PET detector, including:

[0006] Collecting energy data through a dual-ended PET detector;

[0007] Determining the distribution relationship between the DOI ratio and the number of gamma events based on the energy data to obtain a DOI curve;

[0008] Performing equal-area segmentation processing on the DOI curve to obtain multiple DOI boundary values, and calibrating a DOI scale table based on the DOI boundary values; the DOI scale table includes multiple DOI boundary values and the DOI corresponding to each DOI boundary value;

[0009] When a gamma event is detected, looking up the DOI corresponding to the gamma event through the DOI scale table.

[0010] In a second aspect, an embodiment of the present application provides a DOI automatic calibration device for a dual - end PET detector, including:

[0011] A data acquisition module, configured to acquire energy data through the dual - end PET detector;

[0012] A curve drawing module, configured to determine the distribution relationship between the DOI ratio and the number of gamma events according to the energy data, and obtain a DOI curve;

[0013] A calibration module, configured to perform equal - area segmentation processing on the DOI curve to obtain a plurality of DOI boundary values, and calibrate a DOI scale table according to the DOI boundary values; the DOI scale table includes a plurality of DOI boundary values and the corresponding DOI for each DOI boundary value;

[0014] A lookup module, configured to, when a gamma event is detected, look up the DOI corresponding to the gamma event through the DOI scale table.

[0015] In a third aspect, an embodiment of the present application provides a processing terminal, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the DOI automatic calibration method for the dual - end PET detector as described in any one of the above - mentioned first aspects.

[0016] In a fourth aspect, an embodiment of the present application provides a computer - readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the DOI automatic calibration method for the dual - end PET detector as described in any one of the above - mentioned first aspects.

[0017] In a fifth aspect, an embodiment of the present application provides a computer program product. When the computer program product runs on a terminal device, it causes the terminal device to execute the DOI automatic calibration method for the dual - end PET detector as described in any one of the above - mentioned first aspects.

[0018] The beneficial effects of the embodiments of the present application compared with the prior art are as follows: Energy data is acquired through the dual - end PET detector, the distribution relationship between the DOI ratio and the number of gamma events is determined according to the energy data to obtain a DOI curve, equal - area segmentation processing is performed on the DOI curve to obtain a plurality of DOI boundary values, thereby calibrating the DOI scale table, enabling the automatic lookup of the corresponding DOI through the DOI scale table when a gamma event is detected, and at the same time, automatic calibration for DOI curves of different shapes can be achieved, with a small amount of calculation, improving the calibration accuracy and efficiency.

[0019] It can be understood that the beneficial effects of the above second aspect to fifth aspect can be referred to the relevant descriptions in the above first aspect, and will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 is a schematic structural diagram of a DOI automatic calibration system for a dual - end PET detector provided by an embodiment of the present application;

[0022] Figure 2 is a schematic flowchart of a DOI automatic calibration method for a dual - end PET detector provided by an embodiment of the present application;

[0023] Figure 3 is a schematic flowchart of step S103 of the DOI automatic calibration method for a dual - end PET detector provided by an embodiment of the present application;

[0024] Figure 4 is a schematic diagram of a DOI curve provided by an embodiment of the present application;

[0025] Figure 5 is a dual - end PET detector based on an LYSO crystal array coupled with an SiPM array provided by an embodiment of the present application;

[0026] Figure 6 is a schematic structural diagram of a DOI automatic calibration device for a dual - end PET detector provided by an embodiment of the present application;

[0027] Figure 7 is a schematic structural diagram of a processing terminal provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] In the following description, specific details such as specific system structures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present application. However, those skilled in the art should clearly understand that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well - known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present application.

[0029] It should be understood that, as used in the specification of the present application and the appended claims, the term "comprising" indicates the presence of the described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their combinations.

[0030] It should also be understood that the term "and / or" as used in the specification of the present application and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0031] As used in the specification of the present application and the appended claims, the term "if" may be construed, depending on the context, as "when", "once", "in response to determining", or "in response to detecting". Similarly, the phrase "if determined" or "if [the described condition or event] is detected" may be construed, depending on the context, as meaning "once determined", "in response to determining", "once [the described condition or event] is detected", or "in response to detecting [the described condition or event]".

[0032] In addition, in the description of the specification of the present application and the appended claims, the terms "first", "second", "third", etc. are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0033] Reference to "one embodiment" or "some embodiments" or the like described in the specification of the present application means that a specific feature, structure, or characteristic described in connection with that embodiment is included in one or more embodiments of the present application. Thus, statements such as "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc. that appear in different places in this specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "comprising", "including", "having", and their variants all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0034] The DOI automatic calibration method for the dual-ended PET detector provided by the embodiments of the present application can be applied to a processing terminal, such as terminal devices like mobile phones, tablet computers, laptop computers, ultra-mobile personal computers (UMPCs), netbooks, etc. The embodiments of the present application do not impose any restrictions on the specific types of terminal devices.

[0035] In recent years, positron emission tomography (PET) is a molecular imaging technology with high sensitivity and is often used in fields such as tumor imaging and brain science disease research. In a PET imaging system, the inability to quickly and accurately determine the depth of interaction (DOI) is a major factor hindering the simultaneous achievement of uniform high spatial resolution and high efficiency. Traditional methods for determining the depth of interaction based on dual-ended PET detectors usually require a large number of crystals, which are difficult, labor-intensive, or have poor applicability. To solve this problem, this application proposes a DOI automatic calibration method for dual-ended PET detectors, a DOI automatic calibration device for dual-ended PET detectors, a processing terminal, and a computer-readable storage medium. Energy data can be collected by the dual-ended PET detector, the distribution relationship between the DOI ratio and the number of gamma events can be determined based on the energy data to obtain a DOI curve, and the DOI curve is processed by equal-area segmentation to obtain multiple DOI boundary values, thereby calibrating the DOI scale table. When a gamma event is detected, the corresponding DOI can be automatically found through the DOI scale table, and at the same time, automatic calibration for DOI curves of different shapes can be achieved, with a small amount of calculation, improving the calibration accuracy and efficiency.

[0036] To implement the technical solution proposed in this application, a DOI automatic calibration system for a dual-ended PET detector can be constructed first. Please refer to Figure 1 This DOI automatic calibration system for a dual-ended PET detector consists of a dual-ended PET detector and a processing terminal, and the dual-ended PET detector is communicatively connected to the processing terminal.

[0037] Among them, the dual-ended PET detector is a dual-ended PET detector provided with a scintillation crystal containing 176 Lu element (such as LYSO, LSO, etc.), and the processing terminal is a processing device that processes the energy data obtained by scanning with the dual-ended PET detector to determine the depth of interaction scale. During the scanning process, the dual-ended PET detector collects the energy data and sends it to the processing terminal. The processing terminal determines the distribution relationship between the DOI ratio and the number of gamma events based on the energy data to obtain a DOI curve, and the DOI curve is processed by equal-area segmentation to obtain multiple DOI boundary values, thereby calibrating the DOI scale table. When a gamma event is detected, the corresponding DOI can be automatically found through the DOI scale table.

[0038] To illustrate the technical solution proposed in this application, the following will be described through specific embodiments.

[0039] Figure 2A schematic flow chart of a method for automatic DOI calibration of a double-ended PET detector provided in the present application is shown. As an example but not a limitation, the method can be applied in a processing terminal.

[0040] S101. Acquire energy data through a double-ended PET detector.

[0041] Specifically, the double-ended PET detector is a double-ended PET detector provided with a scintillation crystal containing Lu element (such as LYSO, LSO, etc.). 176 The scintillation crystal of the Lu element has background radiation (such as the LYSO crystal itself has uniform background radiation Lu-176), and the energy data (specifically the background radiation signal) collected by the double-ended PET detector can be obtained.

[0042] S102: Determine the distribution relationship between the DOI ratio and the number of gamma events according to the energy data to obtain a DOI curve.

[0043] Specifically, after each gamma ray is detected by the PET detector, the energy data of the light detectors at both ends will be obtained respectively, and then a depth of interaction (DOI) DOI ratio will be obtained by calculating the energy ratio of the energy data. At this time, the number of gamma events corresponding to the corresponding DOI ratio will be increased by one. By detecting a large number of gamma ray events, the distribution relationship between the DOI ratio and the corresponding number of gamma events is determined, and the depth of interaction DOI curve is drawn.

[0044] S103, performing equal-area segmentation processing on the DOI curve to obtain a plurality of DOI boundary values, and calibrating a DOI scale according to the DOI boundary values; the DOI scale includes a plurality of DOI boundary values ​​and a DOI corresponding to each DOI boundary value.

[0045] Specifically, for the gamma rays emitted by the crystal background, the number of gamma rays emitted at different depths is almost the same. When the horizontal axis scale in the DOI curve is detected to be fixed, it is determined that all the areas covered under the DOI curve of the effective depth can be equivalent to the total value. Therefore, the DOI boundary value at the boundary of multiple segments corresponding to different depths can be determined by performing equal area segmentation (or equal counting) processing on the DOI curve, and then the DOI corresponding to each segment DOI boundary value can be determined to calibrate the effective depth scale. Among them, the DOI scale includes multiple DOI boundary values ​​and the DOI corresponding to each DOI boundary value.

[0046] It can be understood that when the DOI curve is processed by equal area to obtain N segments, N-1 DOI boundary values at the boundaries can be correspondingly obtained, so as to determine the DOI corresponding to the DOI boundary value of each segment. For example: the number of segments N of the DOI curve is 8, and the crystal length is 20 mm, then there are 7 boundary values. The actual depth corresponding to each DOI boundary value is 2.5 mm. The determined DOI boundary values are: DOI1 = 0.4, DOI2 = 0.45, DOI3 = 0.5... DOI7 = 0.7. The corresponding calibration table is: working depth (DOI) = 0-2.5 mm, DOI = 0-0.4; working depth = 2.5-5 mm, DOI = 0.4-0.45; working depth = 5-7.5 mm, DOI = 0.45-0.5... working depth = 17.5-20 mm, DOI = 0.65-0.7.

[0047] S104. When a gamma event is detected, look up the DOI corresponding to the gamma event through the DOI scale table.

[0048] Specifically, in the imaging mode, after each gamma ray event is detected, the DOI ratio can be calculated according to the energy ratio, and then the DOI ratio is compared with the above DOI boundary values (that is, each boundary value in the DOI lookup table) to obtain the corresponding segment (that is, the depth ID), and the actual working depth DOI corresponding to the DOI boundary value of this segment is determined.

[0049] For example: the DOI ratio calculated for a certain gamma ray event actually detected is 0.41. Since DOI1 < 0.41 < DOI2, the depth ID of the actual DOI boundary value can be obtained through comparison as 2, and the corresponding actual crystal depth range is 2.5-5 mm. In order to save computing resources and effectively utilize DOI information, the appropriate number of segments is generally set according to the actual DOI resolution. When imaging, the actual depth is determined by the depth ID number of the segment to which the DOI ratio belongs, and the physical coordinates of the gamma ray are located.

[0050] In one embodiment, the determining the distribution relationship between the DOI ratio and the number of gamma events according to the energy data to obtain the DOI curve includes:

[0051] Calculating the DOI ratio according to the energy data;

[0052] Counting the number of gamma events corresponding to the DOI ratio to determine the distribution relationship between the DOI ratio and the number of gamma events, and obtaining the DOI curve.

[0053] Specifically, the energy ratio calculation is performed on the energy data collected by the dual - end PET detector to obtain the DOI ratio. By detecting a large number of gamma - ray events, a lot of gamma - event statistical quantities [DOI_Ratio, Counts] corresponding to different DOI ratios are obtained, so as to determine the distribution relationship between the DOI ratio and the corresponding number of gamma events. Taking the horizontal axis as the interaction depth DOI ratio and the vertical axis as the number of gamma events corresponding to the interaction depth DOI ratio, the interaction depth DOI curve is plotted.

[0054] As Figure 3 shown, in one embodiment, the step S103 includes:

[0055] S1031. Calculate the total area value of the DOI curve according to all DOI ratios and the corresponding number of gamma events;

[0056] S1032. Perform equal - area segmentation processing on the DOI curve based on the total area value, determine multiple segmentation DOI boundary values with the same area, and calibrate the DOI scale table according to the DOI boundary values.

[0057] Specifically, first, in the DOI curve, the sum of all DOI ratios and the corresponding number of gamma events is calculated to obtain the total area Stot of the DOI curve. Assuming that the required DOI scale table includes N segmentation lines, the DOI curve is subjected to equal - area segmentation processing based on the total area value to obtain N equal - area segments. The area corresponding to each segment is S1 = Stot / N. The sum of the number of gamma events in the curve with the same area for each segment is 1 / N of the total number of gamma - ray events in the whole curve, obtaining N - 1 DOI boundary values at the demarcation points, determining the interaction depth DOI corresponding to each segmentation DOI boundary value, and thus calibrating the DOI scale table according to the above - mentioned multiple DOI boundary values and the corresponding interaction depth DOI.

[0058] Figure 4 An exemplary schematic diagram of an interaction depth DOI curve is shown.

[0059] Figure 4 In [the figure], the horizontal axis in the interaction depth DOI curve represents the interaction depth DOI ratio, the vertical axis represents the number of gamma events corresponding to the interaction depth DOI ratio, and the dots on the horizontal axis represent the DOI boundary values at the demarcation points.

[0060] In one embodiment, the dual - end PET detector includes a first PET detector and a second PET detector, and the energy data includes a first energy value collected by the first PET detector and a second energy value collected by the second PET detector.

[0061] Specifically, the dual - ended PET detector includes a first PET detector and a second PET detector. Correspondingly, the energy data collected by the dual - ended PET detector includes: the first energy value collected by the first PET detector and the second energy value collected by the second PET detector.

[0062] In one embodiment, the dual - ended PET detector is provided with a lutetium yttrium silicate crystal array coupled with a silicon photomultiplier tube array.

[0063] Specifically, both the first PET detector and the second PET detector of the dual - ended PET detector are provided with silicon photomultiplier tubes. Between the tube bodies of the first PET detector and the second PET detector, there is 176 a scintillation crystal of Lu element (such as LYSO, LSO, etc.). Therefore, there is a lutetium yttrium silicate crystal array coupled with a silicon photomultiplier tube array between the dual - ended PET detectors.

[0064] In one embodiment, for the energy data collected by the dual - ended PET detector, calculating an energy ratio of the energy data to obtain a DOI ratio includes:

[0065] Obtaining the first energy value and the second energy value collected by the dual - ended PET detector;

[0066] Determining the sum of the first energy value and the second energy value, and calculating the ratio of the first energy value to the sum as the DOI ratio.

[0067] Specifically, obtaining the first energy value collected by the first PET detector and the second energy value collected by the second PET detector in the dual - ended PET detector, and calculating an energy ratio of the first energy value and the second energy value based on the following formula to obtain the DOI ratio:

[0068]

[0069] where E1 represents the first energy value collected by the first PET detector (silicon photomultiplier tube SiPM 1), and E2 represents the second energy value collected by the second PET detector (silicon photomultiplier tube SiPM 2). That is, first calculate and determine the sum of the first energy value and the second energy value, and calculate the ratio between the first energy value and the above - mentioned sum as the DOI ratio.

[0070] Figure 5 An exemplary schematic diagram of a dual - ended PET detector based on a LYSO crystal array coupled with a SiPM array is shown.

[0071] Figure 5In it, silicon photomultipliers are provided at both ends of the dual - end PET detector (i.e., the first PET detector and the second PET detector), and a LYSO scintillation crystal is provided between the tube bodies of the first PET detector and the second PET detector.

[0072] In this embodiment, energy data is collected by the dual - end PET detector, the distribution relationship between the DOI ratio and the number of gamma events is determined based on the energy data to obtain a DOI curve, the DOI curve is processed by equal - area segmentation to obtain a plurality of DOI boundary values, thereby calibrating the DOI scale table. When a gamma event is detected, the corresponding DOI can be automatically found through the DOI scale table, and at the same time, automatic scaling for DOI curves of different shapes can be achieved, with a small amount of calculation, improving the scaling accuracy and efficiency.

[0073] It should be understood that the magnitudes of the sequence numbers of the steps in the above - mentioned embodiments do not mean the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0074] Corresponding to the DOI automatic scaling method of the dual - end PET detector described in the above - mentioned embodiments, Figure 6 The structural block diagram of the DOI automatic scaling device of the dual - end PET detector provided by the embodiment of the present application is shown. For the sake of convenience of description, only the parts related to the embodiment of the present application are shown.

[0075] Refer to Figure 6 , the DOI automatic scaling device 100 of the dual - end PET detector includes:

[0076] A data acquisition module 101, configured to collect energy data through the dual - end PET detector;

[0077] A curve drawing module 102, configured to determine the distribution relationship between the DOI ratio and the number of gamma events based on the energy data to obtain a DOI curve;

[0078] A scaling module 103, configured to perform equal - area segmentation processing on the DOI curve to obtain a plurality of DOI boundary values, and calibrate the DOI scale table according to the DOI boundary values; the DOI scale table includes a plurality of DOI boundary values and the DOI corresponding to each DOI boundary value;

[0079] A lookup module 104, configured to, when a gamma event is detected, look up the DOI corresponding to the gamma event through the DOI scale table.

[0080] In one embodiment, the curve drawing module includes:

[0081] A first calculation unit, configured to calculate the DOI ratio based on the energy data;

[0082] A statistical unit for counting the number of gamma events corresponding to the DOI ratio to determine the distribution relationship between the DOI ratio and the number of gamma events, and obtain a DOI curve.

[0083] In one embodiment, the curve processing module includes:

[0084] A second calculation unit for calculating the total area value of the DOI curve according to all DOI ratios and the corresponding number of gamma events;

[0085] A scale unit for performing equal-area segmentation processing on the DOI curve based on the total area value, determining multiple segmented DOI boundary values with the same area, and calibrating a DOI scale table according to the DOI boundary values.

[0086] In one embodiment, the dual-ended PET detector includes a first PET detector and a second PET detector, and the energy data includes a first energy value collected by the first PET detector and a second energy value collected by the second PET detector.

[0087] In one embodiment, the calculation module includes:

[0088] An energy value acquisition unit for acquiring the first energy value and the second energy value collected by the dual-ended PET detector;

[0089] A third calculation unit for determining the sum of the first energy value and the second energy value, and calculating the ratio of the first energy value to the sum as the DOI ratio.

[0090] In one embodiment, the dual-ended PET detector is provided with a lutetium yttrium silicate crystal array coupled with a silicon photomultiplier tube array.

[0091] In this embodiment, energy data is collected by a dual-ended PET detector, the distribution relationship between the DOI ratio and the number of gamma events is determined according to the energy data to obtain a DOI curve, and equal-area segmentation processing is performed on the DOI curve to obtain multiple DOI boundary values, thereby calibrating the DOI scale table, so that when a gamma event is detected, the corresponding DOI can be automatically found through the DOI scale table, and at the same time, automatic scaling for DOI curves with different shapes can be realized, with a small amount of calculation, improving the scaling accuracy and efficiency.

[0092] It should be noted that for the information interaction, execution process, etc. between the above-mentioned device / units, since they are based on the same concept as the method embodiment of the present application, for their specific functions and the technical effects brought, please refer to the method embodiment part specifically, and will not be elaborated here.

[0093] Figure 7The structural schematic diagram of the processing terminal provided in this embodiment is as follows. As Figure 7 shown, the processing terminal 7 of this embodiment includes: at least one processor 70 ( Figure 7 only one is shown in the figure), a processor, a memory 71, and a computer program 72 stored in the memory 71 and executable on the at least one processor 70. When the processor 70 executes the computer program 72, the steps in any of the above embodiments of the DOI automatic calibration method for the dual-ended PET detector are implemented.

[0094] The processing terminal 7 may be a computing device such as a desktop computer, a notebook, a palm computer, and a cloud server. The processing terminal may include, but is not limited to, a processor 70 and a memory 71. Those skilled in the art can understand that Figure 7 merely examples of the processing terminal 7, which do not constitute a limitation on the processing terminal 7, and may include more or fewer components than shown in the figure, or combine certain components, or different components. For example, it may also include input / output devices, network access devices, etc.

[0095] The so-called processor 70 may be a central processing unit (CPU), and the processor 70 may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0096] In some embodiments, the memory 71 may be an internal storage unit of the processing terminal 7, such as the hard disk or memory of the processing terminal 7. In other embodiments, the memory 71 may also be an external storage device of the processing terminal 7, such as a plug-in hard disk, a smart media card (SMC), a secure digital card (SD), a flash card, etc. equipped on the processing terminal 7. Further, the memory 71 may also include both the internal storage unit and the external storage device of the processing terminal 7. The memory 71 is used to store an operating system, application programs, a boot loader (BootLoader), data, and other programs, such as the program code of the computer program. The memory 71 may also be used to temporarily store data that has been output or will be output.

[0097] Those skilled in the art can clearly understand that, for the convenience and conciseness of description, only the above division of each functional unit and module is used as an example. In actual applications, the above functions can be allocated to different functional units and modules according to needs, 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. Each functional unit and module in the embodiment can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit. In addition, the specific names of each functional unit and module are only for the convenience of mutual distinction and do not limit the protection scope of this application. The specific working processes of the units and modules in the above system can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated here.

[0098] The embodiment of this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps in the foregoing method embodiments can be implemented.

[0099] The embodiment of this application provides a computer program product. When the computer program product runs on a mobile terminal, the mobile terminal can execute the steps in the foregoing method embodiments.

[0100] If the above integrated 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, to implement all or part of the processes in the above method embodiments of this application, a computer program can be used to instruct relevant hardware to complete. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps in the foregoing method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file or some intermediate form, etc. The computer-readable medium can at least include: any entity or device that can carry the computer program code to the photographing device / terminal device, recording medium, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk, or an optical disc, etc. In some jurisdictions, according to legislation and patent practice, the computer-readable medium cannot be an electrical carrier signal and a telecommunication signal.

[0101] In the above embodiments, the descriptions of the respective embodiments each have their own emphasis. For parts not detailed or recorded in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0102] Those of ordinary skill in the art can realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. A professional technician can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of this application.

[0103] In the embodiments provided in this application, it should be understood that the disclosed device / network device and method can be implemented in other ways. For example, the device / network device embodiments described above are merely illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, 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 displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces, and the indirect couplings or communication connections of the devices or units can be in electrical, mechanical or other forms.

[0104] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place, or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0105] The above embodiments are only used to illustrate the technical solutions of this application, rather than to limit it; although this application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included in the protection scope of this application.

Claims

1. A DOI automatic calibration method for a dual - ended PET detector, characterized in that, Including: Collecting energy data through a dual - ended PET detector; Determining the distribution relationship between the DOI ratio and the number of gamma events based on the energy data to obtain a DOI curve; Performing equal - area segmentation on the DOI curve to obtain multiple DOI boundary values, and calibrating a DOI scale based on the DOI boundary values; the DOI scale includes multiple DOI boundary values and the corresponding DOI for each DOI boundary value; When a gamma event is detected, looking up the DOI corresponding to the gamma event through the DOI scale.

2. The DOI automatic calibration method for a dual - ended PET detector according to claim 1, characterized in that, The determining the distribution relationship between the DOI ratio and the number of gamma events based on the energy data to obtain a DOI curve includes: Calculating the DOI ratio based on the energy data; Counting the number of gamma events corresponding to the DOI ratio to determine the distribution relationship between the DOI ratio and the number of gamma events, and obtaining a DOI curve.

3. The DOI automatic calibration method for a dual - ended PET detector according to claim 1, characterized in that, The performing equal - area segmentation on the DOI curve to obtain multiple DOI boundary values and calibrating a DOI scale based on the DOI boundary values includes: Calculating the total area value of the DOI curve based on all DOI ratios and the corresponding number of gamma events; Performing equal - area segmentation on the DOI curve based on the total area value to determine multiple segmented DOI boundary values with the same area, and calibrating the DOI scale based on the DOI boundary values.

4. The DOI automatic calibration method for a dual - ended PET detector according to claim 1, characterized in that, The dual - ended PET detector includes a first PET detector and a second PET detector, and the energy data includes a first energy value collected by the first PET detector and a second energy value collected by the second PET detector.

5. The DOI automatic calibration method for a dual - ended PET detector according to claim 2, characterized in that, The calculating the DOI ratio based on the energy data includes: Obtaining the first energy value and the second energy value collected by the dual - ended PET detector; Determining the sum of the first energy value and the second energy value, and calculating the ratio of the first energy value to the sum as the DOI ratio.

6. The DOI automatic calibration method for a dual - ended PET detector according to claim 3, characterized in that, The dual - ended PET detector is provided with a lutetium yttrium silicate crystal array coupled with a silicon photomultiplier tube array.

7. A DOI automatic calibration device for a dual - ended PET detector, characterized in that, Including: A data acquisition module for collecting energy data through a dual - ended PET detector; A curve drawing module for determining the distribution relationship between the DOI ratio and the number of gamma events based on the energy data to obtain a DOI curve; A scale module for performing equal - area segmentation on the DOI curve to obtain multiple DOI boundary values, and calibrating a DOI scale based on the DOI boundary values; the DOI scale includes multiple DOI boundary values and the corresponding DOI for each DOI boundary value; A lookup module for looking up the DOI corresponding to the gamma event through the DOI scale when a gamma event is detected.

8. The DOI automatic calibration device for a dual - ended PET detector according to claim 7, characterized in that, The curve drawing module includes: A first calculation unit for calculating the DOI ratio based on the energy data; A statistics unit for counting the number of gamma events corresponding to the DOI ratio to determine the distribution relationship between the DOI ratio and the number of gamma events, and obtaining a DOI curve.

9. A processing terminal, including 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, it implements the method according to any one of claims 1 to 6.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method according to any one of claims 1 to 6.

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