PET system performance test method, PET system, equipment and storage medium

Abstract

The invention relates to a PET system performance test method, a PET system, equipment and a storage medium, the PET system comprises a detection tool and scanning equipment, the detection tool comprises a radioactive source and a die body, the scanning equipment is used for scanning the detection tool, and the method comprises the following steps: according to the reciprocating motion parameter of the radioactive source, the axial length of the radioactive source and the axial scanning length of the PET system in the scanning process, determining the performance of the PET system; obtaining the effective scanning time of the radioactive source in the scanning process; acquiring scanning data in the scanning process, wherein the scanning data comprises event count; and obtaining performance parameters of the PET system according to the effective scanning time, the scanning data and the source activity of the radioactive source. According to the method, by calibrating the effective scanning time, deviation caused by line source movement in the scanning process is reduced, the time calibration method is simple, and the problem that when a long-axis system detects a short-axis tool, the method for testing the performance of the PET system is complex is solved.

Description

Technical Field

[0001] The present application relates to the field of PET scanning technology, and in particular to a PET system performance testing method, a PET system, a device and a storage medium. Background Art

[0002] With the development of detectors and reconstruction algorithm technology, positron emission tomography equipment has shown a trend of long-axis development in recent years. The axial length of some PET (positron emission tomography) systems has exceeded the length of standard tooling and phantoms. In this case, the traditional PET system detection method can only cover part of the axial area of ​​the PET system and cannot reflect the status of the entire system, resulting in the measured performance parameters of the PET system cannot accurately reflect the true performance level of the overall system; if a tooling is developed throughout the PET system, there are problems of difficult operation and high tooling production costs.

[0003] The related technology moves the tooling during the PET system detection process and collects data during the tooling movement. According to a certain performance parameter to be calculated, the collected data is spliced, accumulated, and processed to eliminate the data within the coverage of the overlapping phantom radiation source, and the collected data covers the scanning field of view of the long-axis PET system. This type of method has a large amount of calculation and a complex data processing process. In addition, the processed collected data can only be applied to the calculation of a certain fixed parameter, and has a narrow scope of application.

[0004] With regard to the problem in related technologies that the method for testing the performance of the PET system is complicated when using a long-axis system to inspect a short-axis tooling, no effective solution has been proposed so far. Summary of the invention

[0005] Based on this, it is necessary to provide a PET system performance testing method, PET system, equipment and storage medium that can solve the problem of complex PET system performance testing methods when using short-axis tooling to detect long-axis systems in response to the above-mentioned technical problems.

[0006] In a first aspect, the present application provides a PET system performance test method, wherein the PET system comprises a detection tool and a scanning device, wherein the detection tool comprises a radiation source and a phantom, and the scanning device is used to scan the detection tool, and the method comprises:

[0007] Obtaining an effective scanning time of the radiation source during the scanning process according to a reciprocating motion parameter of the radiation source during the scanning process, an axial length of the radiation source, and an axial scanning length of the PET system;

[0008] Acquire scanning data during the scanning process, wherein the scanning data includes event counts;

[0009] The performance parameters of the PET system are obtained according to the effective scanning time, the scanning data and the source activity of the radiation source.

[0010] In one embodiment, the reciprocating motion parameters include an effective motion speed and a motion period, and according to the reciprocating motion parameters of the radiation source during scanning, the axial length of the radiation source, and the axial scanning length of the PET system, the effective scanning time of the radiation source during the scanning process is obtained, including:

[0011] According to the movement period and axial length of the radiation source during the scanning process, a total moving distance of the radiation source is obtained;

[0012] The effective scanning time is obtained according to the total moving distance and the effective moving speed.

[0013] In one embodiment, the reciprocating motion parameter also includes motion duration, and obtaining the effective motion speed of the radiation source includes:

[0014] Obtaining a total scanning length of the scanning process according to the motion cycle and the axial scanning length of the PET system;

[0015] The effective movement speed of the radiation source is obtained according to the total scanning length and the movement duration.

[0016] In one embodiment, obtaining the scan data during the scanning process includes:

[0017] The scan data includes coincidence event counts and random event counts;

[0018] Generate a first chord diagram according to the scan data, and subtract the random event count from the first chord diagram to obtain a second chord diagram;

[0019] A one-dimensional distribution diagram is generated according to the second chord diagram, and a true event count and a scattered event count are obtained according to the one-dimensional distribution diagram.

[0020] In one embodiment, obtaining the real event count and the scattered event count according to the one-dimensional distribution graph includes:

[0021] According to a preset rule, a line segment corresponding to the scattering event count is determined in the one-dimensional distribution graph, and the scattering event count is obtained according to the count corresponding to the line segment;

[0022] The area formed by the line segments is calculated to obtain the true event count.

[0023] In one embodiment, obtaining the scan data during the scanning process includes:

[0024] Acquire initial scanning data collected during the scanning process, and a first activity of the initial scanning data at a time of collection;

[0025] performing decay correction on the initial scan data according to a ratio of a source activity of the radioactive source to the first activity;

[0026] The scanning data is obtained according to the initial scanning data obtained after decay correction.

[0027] In a second aspect, the present application further provides a PET system, the system comprising: a detection tooling, a mobile module, a scanning device and a control module;

[0028] The detection fixture reciprocates along a preset direction in the scanning device under the control of the moving module; wherein the axial length of the detection fixture is less than the axial scanning length of the scanning device;

[0029] The control module is used to execute the PET system performance testing method described in the first aspect above.

[0030] In one embodiment, the detection tool includes a radiation source and a phantom, and the radiation source is placed in the phantom.

[0031] In a third aspect, the present application further provides a computer device, which includes a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the PET system performance test method described in the first aspect is implemented.

[0032] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the PET system performance test method described in the first aspect is implemented.

[0033] The above-mentioned PET system performance test method, PET system, equipment and storage medium, the PET system includes a detection tool and a scanning device, the detection tool includes a radiation source and a phantom, the scanning device is used to scan the detection tool, and the method includes: according to the reciprocating motion parameters of the radiation source during the scanning process, the axial length of the radiation source and the axial scanning length of the PET system, the effective scanning time of the radiation source during the scanning process is obtained; the scanning data during the scanning process is obtained, and the scanning data includes event counts; according to the effective scanning time, the scanning data and the source activity of the radiation source, the performance parameters of the PET system are obtained. By calibrating the effective scanning time, the deviation caused by the movement of the radiation source during the scanning process is reduced, and there is no need to perform complex processing such as accumulation and normalization on the scanning data. The time calibration method is simple, which solves the problem of complex methods for testing the performance of the PET system when the long-axis system detects the short-axis tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A hardware structure block diagram of a terminal of a PET system performance testing method in one embodiment;

[0035] Figure 2 A schematic diagram of a PET system performance test method in one embodiment;

[0036] Figure 3 A schematic diagram of a process for testing the performance of a PET system in another embodiment;

[0037] Figure 4 is a structural block diagram of a PET system in one embodiment;

[0038] Figure 5 A schematic diagram of a PET system scanning method in one embodiment;

[0039] Figure 6 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution 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 used to limit the present application.

[0041] In one embodiment, the method embodiment provided in this embodiment can be executed in a terminal, a computer or a similar computing device. For example, running on a terminal, Figure 1 FIG. 1 is a hardware structure diagram of a terminal of a PET system performance test method according to an embodiment of the present application. Figure 1 As shown, the terminal may include one or more ( Figure 1 Only one is shown in the figure) processor 102 and memory 104 for storing data, wherein processor 102 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA. The above terminal may also include a transmission device 106 and an input and output device 108 for communication functions. It can be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the above terminal. Figure 1 More or fewer components as shown, or with Figure 1 Different configurations shown.

[0042] In one embodiment, the PET system includes a detection tool and a scanning device, the detection tool includes a radiation source, and the scanning device is used to scan the detection tool. During the scanning process, the PET scanning device collects scanning data. Figure 2 FIG. 1 is a flow chart of a method for testing the performance of a PET system according to an embodiment of the present invention. Figure 2 As shown, the method includes the following steps.

[0043] Step 201, obtaining the effective scanning time of the radiation source during the scanning process according to the reciprocating motion parameters of the radiation source during the scanning process, the axial length of the radiation source and the axial scanning length of the PET system.

[0044] Among them, the types of radioactive sources used include but are not limited to linear sources, column sources, and ring sources. The reciprocating motion of the radioactive source refers to the process in which the radioactive source makes a linear reciprocating motion along the axis of the PET system within the scanning field of view of the PET system during the scanning process. Through the reciprocating motion of the radioactive source, the detection tooling containing the radioactive source during the scanning process can cover all scanning axial positions equivalently. The reciprocating motion parameter refers to the data generated during the movement of the radioactive source, which can be the motion time, effective motion speed, etc.

[0045] The axial length of the radiation source is less than the axial scanning length of the PET system. The axial direction refers to the Z axis of the PET system. The axial length of the radiation source and the axial scanning length of the PET system are both the lengths on the Z axis of the PET system. The speed of the reciprocating motion can be a uniform motion or a variable speed motion. The motion cycle can be an integer cycle or a non-integer cycle.

[0046] Exemplarily, the total movement distance of the radiation source during the scanning process is obtained according to the reciprocating motion parameters of the radiation source and the axial length of the radiation source. When the total movement distance and the effective movement speed of the radiation source are obtained, the effective scanning time of the radiation source can be calculated according to the relationship between the distance, speed and time.

[0047] Step 202, obtaining scanning data during the scanning process, where the scanning data includes event counts.

[0048] The scanning data is the events of the radioactive source collected by the scanning device of the PET system during the scanning process. The scanning signal includes the event count and may also include information such as the crystal position and energy corresponding to the event count.

[0049] For example, the scanning module of the PET system collects events occurring at the current moment every 1 ms, and stores the collected data in a .raw file format. The stored file is parsed to obtain multiple time slice information, and the parsed time slice information is used as scanning data.

[0050] Step 203, obtaining the performance parameters of the PET system according to the effective scanning time, the scanning data and the source activity of the radiation source.

[0051] The performance parameters of the PET system include, but are not limited to, the sensitivity of the system, the time count rate, the scatter fraction, the equivalent noise count rate, the time resolution, etc. Optionally, the sensitivity of the system is obtained based on the effective scanning time, the source activity of the radiation source, and the event count. The scatter fraction is obtained based on the scanning data and the event count. The count rate of each event and the equivalent noise count rate are obtained based on the event counts in the scanning data and the effective scanning time.

[0052] In the above PET system performance test method, since the scanning device fixes the scanning field of view during the reciprocating motion of the radiation source, the scanning data generated at the same position of the radiation source will be obtained multiple times, resulting in the total time of the reciprocating motion of the radiation source during the scanning process being different from the effective time of the radiation source receiving the PET scan, which will result in the inability to obtain the PET system performance based on the scanning time and scanning data. For this reason, this embodiment corrects the total time of the reciprocating motion of the radiation source according to the reciprocating motion parameters, the axial length of the radiation source and the axial scanning length of the PET system to obtain the effective scanning time of the radiation source. Various performance parameters are obtained using the effective scanning time and scanning data. The effective scanning time of the radiation source is obtained by calibrating the scanning time of the radiation source to reduce the deviation caused by the movement of the radiation source during the scanning process, without the need for complex processing such as accumulation and normalization of the scanning data. Since various events occur in a large number of crystal atoms contained in the radiation source during the scanning process, the amount of scanning data is large and the processing of the scanning data is relatively complex. The data magnitude of the reciprocating motion parameters, axial length and axial scanning length time, which are data related to the correction of the effective scanning time, is much smaller than the scanning data, so the amount of time calibration calculation is small. Therefore, the time correction method is simpler than the scan data correction. The PET system performance test method of this embodiment solves the problem of complex PET system performance test method when using short-axis tooling to detect the long-axis system.

[0053] In one embodiment, the reciprocating motion parameters include an effective motion speed and a motion period. The effective scanning time of the radiation source during the scanning process is obtained according to the reciprocating motion parameters of the radiation source during the scanning process, the axial length of the radiation source and the axial scanning length of the PET system, including: obtaining the total moving distance of the radiation source according to the motion period and axial length of the radiation source during the scanning process; and obtaining the effective scanning time according to the total moving distance and the effective motion speed.

[0054] Among them, the reciprocating motion of the radiation source is recorded as a motion cycle, and the motion cycle is the number of reciprocating motions of the radiation source during the scanning process. In one motion cycle, the radiation source realizes one reciprocating motion. Therefore, the product of the motion cycle of the radiation source and the axial length is multiplied by a multiple of 2 to obtain the total moving distance of the radiation source. When the total moving distance and speed are known, according to the physical relationship between distance, speed and time, the total moving distance is divided by the effective motion speed to obtain the effective scanning time.

[0055] Obtaining the effective movement speed of the radiation source includes: obtaining the movement cycle and movement duration of the radiation source during the scanning process; obtaining the total scanning length of the scanning process according to the movement cycle and the axial scanning length of the PET system; and obtaining the effective movement speed of the radiation source according to the total scanning length and the movement duration.

[0056] The motion duration is the time from the start of the movement of the radiation source to the end of the movement during the scanning process. In one motion cycle, a certain scanning field of view of the scanning device can repeatedly obtain the scanning data generated by the same position of the radiation source. Therefore, the product of the motion cycle and the axial scanning length of the PET system is multiplied by 2 to obtain the total scanning length. When the total scanning length and motion duration are known, the effective motion speed can be obtained by dividing the total scanning length by the motion duration based on the physical relationship between distance, speed and time.

[0057] For example, the axial scanning length of the PET system is AFOV, and the actual length of the radiation source is L. During the scanning process, the radiation source moves at a constant speed (V) in the entire axial scanning length AFOV, and repeats an integer number of movement cycles N, the movement duration is T, and the effective time T is obtained. eff :

[0058]

[0059] In one embodiment, acquiring scanning data during a scanning process includes: acquiring initial scanning data acquired during the scanning process, and a first activity of the initial scanning data at the acquisition time; performing decay correction on the initial scanning data according to a ratio of a source activity of a radiation source to the first activity; and obtaining scanning data according to the initial scanning data obtained after the decay correction.

[0060] Activity characterizes the radioactivity intensity of a radioactive source, that is, how many times a radioactive source decays per unit time. The source activity is the activity of the radioactive source at the time t0 when data collection begins, and the first activity is the activity of the radioactive source at time tc during the scanning process. The activity of the radioactive source decreases over time during the decay process. Therefore, the activity of the radioactive source in the scan data collected at different times is different. The relationship between the first activity and the source activity is:

[0061]

[0062] Among them, the first activity is A c , the source activity is A0, and the half-life of the radioactive source is T 1 / 2 , half-life refers to the time required for the intensity of a radioactive source to decrease to half.

[0063] Decay correction refers to correcting the first activity of the scan data according to the source activity, so as to obtain the scan data at the same time. According to the relationship between the first activity and the source activity at time tc, the initial scan data C is decay corrected to obtain the corrected scan data C m :

[0064] C m =C×(A0 / A c )

[0065] According to the scanning data at the same time, the system performance parameters relative to the same time are obtained, which can improve the accuracy of the system performance test.

[0066] In one embodiment, scanning data is obtained during a scanning process, including: the scanning data includes a coincidence event count and a random event count; a first chord diagram is generated according to the scanning data, the random event count is subtracted from the first chord diagram to obtain a second chord diagram, and a one-dimensional distribution diagram is generated according to the second chord diagram.

[0067] The scan data is the data collected by the PET system, stored in a list format, and the stored file format is (.raw). The scan data includes prompt counts (matching event counts) and random counts (random event counts). A chord diagram is a three-dimensional data arrangement that includes three directions.

[0068] Optionally, the scan data is rearranged in the manner of SSRB (Single Slice ReBinning, single-layer rearrangement algorithm), and the scan data is traversed to obtain the first chord diagram of prompt (conforming event) counts and random (random event) counts. After deducting the random counts on the basis of the first chord diagram, the second chord diagram f(irad, iphi, islice) of true (real event) counts and scatter (scattered event) counts is obtained. Among them, irad is radial, iphi is angular direction, and islice represents the axial layer. Obtain the 2D chord diagram of each axial layer slice i in the second chord diagram f(irad, iphi, islice), and move the maximum value of the one-dimensional distribution of the iphi angle in the 2D chord diagram under each slice i to irad=0, so as to superimpose and obtain the one-dimensional distribution f of the second chord diagram. i. Among them, slice is used to identify the axial dimension of the chord diagram data, and i is a positive integer corresponding to the axial layer number of the chord diagram.

[0069] Generate a one-dimensional distribution graph, and obtain the real event count and the scattered event count according to the one-dimensional distribution graph, including: according to a preset rule, determine the line segment corresponding to the scattered event count in the one-dimensional distribution graph, and obtain the scattered event count according to the count corresponding to the line segment; calculate the area formed by the line segment to obtain the real event count.

[0070] The coincidence event count is the total number of coincidence events within the PET scanning field of view during the scanning process. Only a portion of the coincidence event count is the true coincidence event, that is, the event of two 511keV photons moving back to back produced by the annihilation of positrons and electrons. The true event count is obtained based on the true coincidence event and recorded as the true count. In the scanning data, in addition to the coincidence event count, true event count, and scattering event count, there is also a random event count.

[0071] The preset rule may be to generate a line where irad=-2cm and irad=+2cm in the one-dimensional distribution graph. Optionally, the count values ​​under the irad line corresponding to -2cm and +2cm are obtained to obtain the scattering event count C. scatter,i . Calculate the area formed by the line segment and get the true event count C true,i .

[0072] According to the scan data, the coincidence event count, random event count, true event count and scattered event count respectively obtained can be used to calculate various system performance parameters. Optionally, the sensitivity of the system is obtained according to the effective scan time, the source activity of the radiation source and the true event count. The scattering score is obtained according to the scan data and the true event count. According to the event counts in the scan data and the effective scan time, the count rate of each event and the equivalent noise count rate are obtained.

[0073] In one embodiment, Figure 3 A flow chart of a preferred PET system parameter performance test method is provided. In this embodiment, the radiation source is a line source. The PET system includes a detection tool, which includes a phantom and a line source. The line source is located in the phantom. Figure 3 As shown, the method comprises the following steps:

[0074] Step 301, obtain scanning data. The axial scanning length of the PET system is AFOV, and the start time of data acquisition is t0. During the scanning process, the phantom reciprocates in the entire axial range, equivalently covering all axial positions, and the data during the scanning process is collected to obtain the initial scanning data C. The initial scanning data is stored in List-mode (list mode data) format, and the initial scanning data contains the data acquisition time. According to the time information in the initial scanning data, the data acquisition time t is calculated. c (e.g. 1ms) activity A c :

[0075]

[0076] Among them, A0 is the source activity of the line source, and the half-life of the radioactive source is T 1 / 2 , half-life refers to the time required for the intensity of a radioactive source to decrease to half.

[0077] Perform decay correction on the initial scan data to obtain the corrected scan data C m :

[0078] C m =C×(A0 / A c )

[0079] After the decay correction, the scan data is rearranged in the SSRB way. After traversing all the scan data, the first chord diagram of prompt counts and random counts is obtained, and the second chord diagram f(irad, iphi, islice) of true counts and scatter counts is obtained after deducting the random counts.

[0080] In the 2D chord diagram under each slice i, the maximum value of the one-dimensional distribution of angle iphi is moved to irad = 0, and the one-dimensional distribution f is obtained by superposition. i Get the line corresponding to -2cm and +2cm of irad, and use the count under the line as the scatter count C scatter,i The area formed by the connecting lines is the true count C true,i .

[0081] Step 302, obtain the effective motion time. Specifically, the actual length of the line source is L, and the source activity is A0. The line source reciprocating motion parameters include the effective motion speed V, the motion cycle N, and the motion duration T. The effective motion time T eff for:

[0082]

[0083] Step 303: Obtain system sensitivity. First, obtain the sensitivity S of each slice i based on the true count, effective motion time, and source activity. i , and then according to S i The overall sensitivity S of the system is calculated. Among them,

[0084]

[0085] S=Σ i S i

[0086] Step 304: Obtain the system scatter score. scatter,i and the true count C true,i , calculate the scattering fraction SF for each Slice i i , according to SF i : Calculate the scattering fraction SF of the entire system. Among them,

[0087]

[0088] SF=∑ i SF i

[0089] Step 305, obtaining the event count rate and the system equivalent noise count rate; specifically, calculating the event count rate according to the following formula, including:

[0090] prompt count rate:

[0091] Random count rate:

[0092] True count rate:

[0093] Scatter count rate:

[0094] Among them, C prompt,i Counts prompts; C random,i Counts random.

[0095] The system equivalent noise count rate is obtained based on the true count rate and prompt count rate:

[0096]

[0097] In this embodiment, necessary corrections are made to the relative position and time of the phantom or radiation source during the movement to obtain the effective movement time. Based on the time slice information in the data, decay correction is made to the data in each time slice to obtain the count relative to the same moment. The corrected effective movement time and the decay-corrected scanning data are applied to the calculation of multiple system performance parameters. The method of effective movement time and decay correction is simple, which reduces the complexity of data processing and simplifies the method of obtaining system performance parameters.

[0098] In addition, in this embodiment, when the long-axis system is used to detect the short-axis tooling, the phantom reciprocates within the entire axial range, equivalently covering all axial positions, so that the obtained scanning data can reflect the status of the entire system.

[0099] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0100] Based on the same inventive concept, the embodiment of the present application also provides a PET system for implementing the PET system performance test method involved above. The implementation scheme for solving the problem provided by the PET system is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more PET system embodiments provided below can refer to the limitations of the PET system performance test method above, and will not be repeated here.

[0101] In one embodiment, Figure 4 As shown, a structural block diagram of a PET system is provided. The PET system includes: a detection tool, a moving module, a scanning device and a control module; the detection tool reciprocates along a preset direction in the scanning device under the control of the moving module; wherein the axial length of the detection tool is less than the axial scanning length of the scanning device; the control module is used to execute the PET system performance test method in any of the above embodiments.

[0102] The preset direction is the Z axis of the PET system, and the moving module may be a scanning bed moving along the Z axis. Figure 5 Schematic diagram of fixed scanning mode and mobile scanning mode of PET system. Figure 5 (a) is a fixed scanning mode of the PET system. During the scanning process, the phantom in the fixed scanning mode is fixed at the axial center of the PET system. Figure 5 (b) is a mobile scanning mode. During the scanning process, the detection fixture in the mobile scanning mode is placed on the scanning bed, and the scanning bed drives the detection fixture to move uniformly at a speed V for an integer (N) period within the entire axial scanning length AFOV of the PET system. This allows the detection fixture to cover all axial scanning positions of the PET system equivalently during the scanning process.

[0103] The detection tooling includes a phantom and a radioactive source, and the radioactive source is placed in the phantom. The detection tooling can be an NEC (noise equivalent count rate) phantom and a radioactive source, or an aluminum tube and a radioactive source with NEMA sensitivity, or other types of phantoms and radioactive sources. When the detection tooling is an aluminum tube and a radioactive source with NEMA sensitivity, the radioactive source and the aluminum tube are connected to the bedside through the tooling, and then the mobile scanning method is used for data collection and analysis.

[0104] Each module in the above PET system can be implemented in whole or in part by software, hardware or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute the operations corresponding to each module.

[0105] In one embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as follows: Figure 6 As shown. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. The processor, the memory and the input / output interface are connected via a system bus, and the communication interface, the display unit and the input device are connected to the system bus via the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a PET system performance test method is implemented.

[0106] Those skilled in the art will understand that Figure 6The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0107] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0108] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-described method embodiments are implemented.

[0109] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above-mentioned method embodiments when executed by a processor.

[0110] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0111] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0112] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A PET system performance test method, wherein the PET system comprises a detection tool and a scanning device, wherein the detection tool comprises a radiation source and a phantom, and the scanning device is used to scan the detection tool, characterized in that: The method comprises: Obtaining an effective scanning time of the radiation source during the scanning process according to a reciprocating motion parameter of the radiation source during the scanning process, an axial length of the radiation source, and an axial scanning length of the PET system; Acquire scanning data during the scanning process, wherein the scanning data includes event counts; The performance parameters of the PET system are obtained according to the effective scanning time, the scanning data and the source activity of the radiation source.

2. The method according to claim 1, characterized in that The reciprocating motion parameters include an effective motion speed and a motion period. According to the reciprocating motion parameters of the radiation source during scanning, the axial length of the radiation source, and the axial scanning length of the PET system, the effective scanning time of the radiation source during the scanning process is obtained, including: According to the movement period and axial length of the radiation source during the scanning process, a total moving distance of the radiation source is obtained; The effective scanning time is obtained according to the total moving distance and the effective moving speed.

3. The method according to claim 2, characterized in that The reciprocating motion parameter also includes the motion duration, and obtaining the effective motion speed of the radiation source includes: Obtaining a total scanning length of the scanning process according to the motion cycle and the axial scanning length of the PET system; The effective movement speed of the radiation source is obtained according to the total scanning length and the movement duration.

4. The method according to claim 1, characterized in that Acquiring scanning data during the scanning process includes: The scan data includes coincidence event counts and random event counts; Generate a first chord diagram according to the scan data, and subtract the random event count from the first chord diagram to obtain a second chord diagram; A one-dimensional distribution diagram is generated according to the second chord diagram, and a true event count and a scattered event count are obtained according to the one-dimensional distribution diagram.

5. The method according to claim 4, characterized in that Obtaining true event counts and scattered event counts according to the one-dimensional distribution graph includes: According to a preset rule, a line segment corresponding to the scattering event count is determined in the one-dimensional distribution graph, and the scattering event count is obtained according to the count corresponding to the line segment; The area formed by the line segments is calculated to obtain the true event count.

6. The method according to claim 1, characterized in that Acquiring scanning data during the scanning process includes: Acquire initial scanning data collected during the scanning process, and a first activity of the initial scanning data at the time of collection; performing decay correction on the initial scan data according to a ratio of a source activity of the radioactive source to the first activity; The scanning data is obtained according to the initial scanning data obtained after decay correction.

7. A PET system, characterized in that: The system comprises: a detection tool, a mobile module, a scanning device and a control module; The detection fixture reciprocates along a preset direction in the scanning device under the control of the moving module; wherein the axial length of the detection fixture is less than the axial scanning length of the scanning device; The control module is used to execute the steps of the method according to any one of claims 1 to 6.

8. The system according to claim 7, characterized in that The detection tool comprises a radiation source and a phantom, wherein the radiation source is placed in the phantom.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

Images