Calibration method and device of PET system, computer device and storage medium

Abstract

The application relates to a PET system correction method, device, computer equipment and storage medium. The method comprises the following steps: obtaining a target acquisition instruction; the target acquisition instruction is used for indicating that data acquisition of a current detection unit of a PET system has been completed; moving a scanning bed to a next detection unit of the PET system for data acquisition according to the target acquisition instruction, and correcting the PET system according to scanning data of the current detection unit to obtain a correction result corresponding to the current detection unit; taking the next detection unit as a new current detection unit, and cyclically executing the step of obtaining the target acquisition instruction until the correction results of all the detection units are obtained; and obtaining a correction result of the PET system based on the correction results of all the detection units. In the method, the data acquisition process and the data analysis process are strongly coupled, so that the time of system correction can be shortened, and the system correction efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of medical imaging equipment technology, and in particular to a calibration method, apparatus, computer equipment, and storage medium for a PET system. Background Technology

[0002] Positron emission tomography (PET) is a medical imaging device used to examine the activity of internal organs and tissues. Over long-term use, the hardware of a PET system can degrade, leading to a decrease in system performance. In such cases, a service engineer needs to perform active calibration of the PET system on-site.

[0003] When the PET system is a PET system, it is usually necessary to perform multi-bed data acquisition on the PET system according to the length of the radiation source in order to achieve active calibration of the PET system.

[0004] However, the traditional calibration process for PET systems has the problem of long calibration time. Summary of the Invention

[0005] Therefore, it is necessary to provide a PET system calibration method, apparatus, computer equipment, computer-readable storage medium, and computer program product that can shorten the calibration time of the PET system and improve the system calibration efficiency, in order to address the above-mentioned technical problems.

[0006] In a first aspect, this application provides a calibration method for a PET system. The PET system includes a scanning cavity and a scanning bed. The scanning cavity includes multiple detection units arranged along an axial direction, and the scanning bed is capable of entering and exiting the scanning cavity along an axial direction. The method includes:

[0007] Obtain the target acquisition command; the target acquisition command is used to indicate that data acquisition of the current detection unit of the PET system has been completed.

[0008] According to the target acquisition command, the scanning bed is controlled to move to the next detection unit of the PET system to acquire data, and the current detection unit of the PET system is calibrated according to the scanning data of the current detection unit to obtain the calibration result of the current detection unit;

[0009] The next detection unit is used as the new current detection unit, and the steps of acquiring target acquisition instructions are executed repeatedly until the calibration results of all detection units are obtained. Based on the calibration results of all detection units, the calibration result of the PET system is obtained. The step of moving the scanning bed to the next detection unit of the PET system is used to characterize the movement of the radiation source phantom set on the scanning bed to the preset position corresponding to the next detection unit.

[0010] In one embodiment, the calibration result of the PET system is obtained based on the calibration results of all detection units, including:

[0011] Statistical analysis was performed on the calibration results of all detection units to obtain the calibration results of the PET system.

[0012] In one embodiment, the method further includes:

[0013] After completing the data acquisition of the current detection unit of the PET system, acquire the scanning data of the PET system;

[0014] The scanning data of the PET system is filtered by single-event data and / or coincident event data of the current detection unit to obtain the scanning data of the current detection unit.

[0015] In one embodiment, the current detection unit of the PET system is calibrated based on the scanning data of the current detection unit to obtain the calibration result of the current detection unit, including:

[0016] The scanning data of the current detection unit is preprocessed to obtain the processed scanning data of the current detection unit;

[0017] A preset calibration algorithm is used to calibrate the current detection unit of the PET system based on the processed scan data of the current detection unit, and the calibration result of the current detection unit is obtained.

[0018] In one embodiment, the scanning data of the current detection unit includes single-event data. A preset correction algorithm is used to correct the current detection unit of the PET system based on the processed scanning data, resulting in a correction result for the current detection unit, including:

[0019] A position correction algorithm is used to correct the crystal position of the current detection unit of the PET system based on the processed scan data of the current detection unit, and an intermediate correction result is obtained.

[0020] An energy correction algorithm is used to perform energy correction on the current detection unit of the PET system based on intermediate correction results and the processed scan data of the current detection unit, so as to obtain the correction result of the current detection unit.

[0021] In one embodiment, the scan data of the current detection unit includes coincidence event data. A preset correction algorithm is used to correct the current detection unit of the PET system based on the processed scan data, resulting in a correction result for the current detection unit, including:

[0022] Using a preset correction algorithm, the crystal position, energy, and time-of-flight corrections of the current detection unit in the PET system are performed based on the processed scan data of the current detection unit, and the correction result of the current detection unit is obtained.

[0023] In one embodiment, the method further includes:

[0024] The PET system is controlled to perform a PET scan on the object to be scanned, thereby obtaining the scan data of the object.

[0025] Based on the calibration results and scanning data of the PET system, image reconstruction is performed to obtain the PET image of the object to be scanned.

[0026] Secondly, this application also provides a calibration device for a PET system. The PET system includes a scanning cavity and a scanning bed. The scanning cavity includes multiple detection units arranged along the axial direction, and the scanning bed is capable of entering and exiting the scanning cavity along the axial direction. The device includes:

[0027] The acquisition module is used to acquire target acquisition instructions; target acquisition instructions indicate that data acquisition of the current detection unit of the PET system has been completed.

[0028] The calibration module is used to control the scanning bed to move to the next detection unit of the PET system for data acquisition according to the target acquisition command, and to calibrate the current detection unit of the PET system according to the scanning data of the current detection unit to obtain the calibration result of the current detection unit; to take the next detection unit as the new current detection unit, and to repeatedly execute the step of acquiring the target acquisition command until the calibration results of all detection units are obtained; based on the calibration results of all detection units, the calibration result of the PET system is obtained; wherein, the movement of the scanning bed to the next detection unit of the PET system is used to characterize the movement of the radiation source phantom set on the scanning bed to the preset position corresponding to the next detection unit.

[0029] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the PET system calibration method described in the first aspect above.

[0030] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the PET system calibration method described in the first aspect above.

[0031] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the calibration method for the PET system described in the first aspect above.

[0032] The aforementioned PET system calibration method, apparatus, computer equipment, storage medium, and computer program product are applied to a PET system. The PET system includes a scanning cavity and a scanning bed. The scanning cavity includes multiple detection units arranged along the axial direction. The scanning bed can move in and out of the scanning cavity along the axial direction. In the process of calibrating a PET system in a medical scanning device using this method, a target acquisition command is obtained to indicate that data acquisition of the current detection unit of the PET system has been completed. Based on this target acquisition command, the scanning bed is controlled to move to the next detection unit of the PET system for data acquisition. The current detection unit is then calibrated based on its scanning data to obtain the calibration result. Next, the next detection unit is used as the new current detection unit, and the step of obtaining the target acquisition command is repeated until the calibration results of all detection units are obtained. Based on the calibration results of all detection units, the calibration result of the PET system is obtained. The movement of the scanning bed to the next detection unit of the PET system indicates that the radiation source phantom on the scanning bed has moved to a preset position corresponding to the next detection unit.

[0033] Therefore, the method proposed in this application, when calibrating the PET system, does not involve the traditional method of first completing multi-bed scanning of the PET system, then fusing the scan data obtained from the multi-bed scanning to obtain the PET system's scan data, and then calibrating the PET system based on the PET system's scan data. Instead, when scanning the next detection unit of the PET system, the previous detection unit is calibrated simultaneously based on the scan data collected from the previous detection unit. In other words, this application optimizes and adjusts the system calibration workflow, strongly coupling the data acquisition process and the data analysis process. That is, the data acquisition process and the data analysis process are executed in parallel. After the data of one detection unit is collected, the detection unit can be calibrated without waiting for the data of all detection units to be collected before the calibration operation can be performed. This can shorten the system calibration time and improve the system calibration efficiency.

[0034] In addition, each detection unit of the PET system undergoes independent data acquisition and analysis, allowing for independent system calibration of each detection unit, rather than calibrating the entire PET system based on the scanning data of the entire PET system. Therefore, the amount of data required for the calibration algorithm can be reduced, and the calibration efficiency of the system can be further improved while ensuring calibration accuracy. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a diagram illustrating the application environment of a calibration method for a PET system in one embodiment.

[0037] Figure 2 This is a flowchart illustrating a calibration method for a PET system in one embodiment;

[0038] Figure 3 This is a flowchart illustrating the calibration method for a PET system in another embodiment;

[0039] Figure 4 This is a flowchart illustrating the calibration method for a PET system in another embodiment;

[0040] Figure 5 This is a schematic diagram of the detection unit of a PET system in one embodiment;

[0041] Figure 6 This is a flowchart illustrating the calibration method for a PET system in another embodiment;

[0042] Figure 7 This is a structural block diagram of the calibration device of a PET system in one embodiment;

[0043] Figure 8 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0045] In daily use, calibration and maintenance of the PET system is a crucial component. Regular maintenance and upkeep ensure the system is in optimal condition for patient imaging, resulting in high-quality PET scans. However, as the hardware of the PET system degrades over time, performance degradation and other problems arise. In such cases, a service engineer needs to perform active calibration on-site.

[0046] Typically, for long-axis PET systems, which consist of multiple detection units, data from each detection unit needs to be collected during calibration to fully cover all crystal modules of the long-axis PET system in order to achieve accurate calibration of the system.

[0047] Traditionally, data acquisition from multiple beds (one bed corresponding to one detection unit) is required based on the length of the radiation source. After the multi-bed data acquisition is completed, the acquired multi-bed data is uniformly analyzed, and the correction algorithm is calculated and the results are generated based on the analyzed data. However, the traditional correction method suffers from the problem of long correction time.

[0048] Based on this, this application proposes a calibration method for PET systems. By adopting a parallel accelerated workflow, the traditional calibration workflow is improved and optimized. This method allows for parallel invocation of calibration algorithms for each bed without waiting for all multi-bed data acquisition to be completed, thereby accelerating the overall calibration time, improving the calibration efficiency of the PET system, and ultimately enhancing the energy efficiency of service engineers.

[0049] The calibration method for the PET system provided in this application embodiment can be applied to, for example... Figure 1 The application environment shown is described. The medical scanning device 102 may include PET equipment such as a positron emission tomography (PET) device, a positron emission tomography / computed tomography (PET / CT) device, or a positron emission tomography / magnetic resonance imaging (PET / MR) device, or an integrated PET device. It should be noted that this medical scanning device incorporates a PET scanning system, referred to as the PET system.

[0050] For example, the medical scanning device can be an imaging scanning device equipped with a long-axis scanning system, where a long-axis scanning system refers to a scanning system with a large axial scanning field of view, capable of whole-body scanning, thereby providing high-quality, high-resolution scan images. Conversely, a short-axis scanning system mainly scans local parts of the human body, such as the brain, lungs, and abdomen, and provides scan images of relatively poor quality.

[0051] In one exemplary embodiment, such as Figure 2 As shown, a calibration method for a PET system is provided, which is applied to... Figure 1Taking a medical scanning device as an example, the process includes steps 202 to 204. Wherein:

[0052] Step 202: Obtain the target acquisition command; the target acquisition command is used to indicate that the data acquisition of the current detection unit of the PET system has been completed.

[0053] For long-axis PET systems, it is typically necessary to divide the system into multiple detection units. During system calibration, the scanning bed, in which the radiation source is placed, needs to be moved sequentially to each detection unit. With the radiation source in each detection unit, the system is controlled to scan the source, thereby obtaining scan data for each detection unit, achieving multi-bed scanning. Moving the scanning bed to each detection unit involves moving the radiation source to a preset position corresponding to each unit, such as the center position. In some implementations, the radiation source can also be moved to the center position of each detection unit by shifting its position on the scanning bed, thus enabling data acquisition for each unit.

[0054] For example, during system calibration, the medical scanning device can acquire a system calibration command and determine multiple detection units based on the command. Then, according to the position of the radiation source, the scanning bed is controlled to move to the first detection unit. When the radiation source is located at the center of the first detection unit, the PET system is controlled to scan the radiation source, obtaining scan data corresponding to the first detection unit. After the first detection unit scan is completed, a target acquisition command can be sent to the PET system. This command indicates that data acquisition for the first detection unit of the PET system has been completed. The target acquisition command also instructs data acquisition for the next detection unit, i.e., the second detection unit. Using the same method, data is acquired sequentially for each detection unit of the PET system, thereby obtaining scan data for each detection unit.

[0055] For example, the medical scanning device can perform system calibration on its PET system according to a preset calibration cycle or preset calibration time point; it can also automatically perform system calibration on the PET system after the medical scanning device is turned on; or it can perform system calibration on the PET system after receiving a manual trigger from the user; for example, the medical scanning device can be set to perform system calibration once a week, or it can be set to perform system calibration before working every day, such as at 8 am, or it can be set to perform system calibration after the medical scanning device is turned on, etc.

[0056] In addition, when medical scanning equipment determines multiple detection units corresponding to a PET system, it can divide the crystal module in the detector of the PET system according to the size of the radiation source to obtain multiple detection units; or it can divide the crystal module in the detector of the PET system according to the division parameters input by the user, such as the number of detection units, to obtain multiple detection units, etc. In the embodiments of this application, there are no specific limitations on the division method of the detection units and the number of detection units.

[0057] Step 204: According to the target acquisition command, control the scanning bed to move to the next detection unit of the PET system to acquire data, and calibrate the current detection unit of the PET system according to the scanning data of the current detection unit to obtain the calibration result of the current detection unit.

[0058] The movement of the scanning bed to the next detection unit of the PET system is used to characterize the movement of the radioactive source phantom set on the scanning bed to the preset position corresponding to the next detection unit.

[0059] For example, after the current detection unit of the PET system completes scanning, on the one hand, the scanning bed can be controlled to move to the next detection unit of the PET system for data acquisition; on the other hand, the scanning data of the current detection unit can be acquired, and the current detection unit of the PET system can be calibrated based on the scanning data of the current detection unit to obtain the calibration result of the current detection unit. In other words, during system calibration, the data acquisition process is coupled with the data analysis process. Data acquisition is performed simultaneously, and system calibration of the corresponding detection unit in the PET system is performed based on the acquired data, thereby reducing the system calibration time and improving the system calibration efficiency.

[0060] For example, when calibrating the PET system based on the scanning data of the current detection unit, the calibration can be performed on each crystal module within the current detection unit of the PET system, and the calibration results of each crystal module within the current detection unit can be obtained. For example, in the case of a long-axis PET system, when performing system calibration, the position of each crystal module can be calibrated, the energy of each crystal module can be calibrated, and the flight time of each crystal module can be calibrated, etc.

[0061] Step 206: The next detection unit is taken as the new current detection unit, and the step of acquiring the target acquisition command is executed repeatedly until the calibration results of all detection units are obtained; based on the calibration results of all detection units, the calibration result of the PET system is obtained.

[0062] In other words, by using the parallel processing operation described above, data acquisition and correction operations can be performed on each detection unit in sequence, thereby obtaining the correction results of all detection units.

[0063] Furthermore, given the calibration results of each detection unit in the PET system, the calibration result of the PET system can be obtained based on the calibration results of each detection unit; for example, the calibration results of each detection unit can be fused to obtain the calibration result of the PET system.

[0064] The aforementioned PET system calibration method can be applied to a PET system, which includes a scanning cavity and a scanning bed. The scanning cavity includes multiple detection units arranged along the axial direction, and the scanning bed can move in and out of the scanning cavity along the axial direction. In the process of calibrating a PET system in a medical scanning device using this method, a target acquisition command is obtained to indicate that data acquisition of the current detection unit of the PET system has been completed. Based on this target acquisition command, the scanning bed is controlled to move to the next detection unit of the PET system for data acquisition. The current detection unit is then calibrated based on its scanning data to obtain the calibration result. Next, the next detection unit is used as the new current detection unit, and the step of obtaining the target acquisition command is repeated until the calibration results of all detection units are obtained. Based on the calibration results of all detection units, the calibration result of the PET system is obtained. The movement of the scanning bed to the next detection unit of the PET system indicates that the radiation source phantom on the scanning bed has moved to a preset position corresponding to the next detection unit.

[0065] Therefore, the method proposed in this application, when calibrating the PET system, does not involve the traditional method of first completing multi-bed scanning of the PET system, then fusing the scan data obtained from the multi-bed scanning to obtain the PET system's scan data, and then calibrating the PET system based on the PET system's scan data. Instead, when scanning the next detection unit of the PET system, the previous detection unit is calibrated simultaneously based on the scan data collected from the previous detection unit. In other words, this application optimizes and adjusts the system calibration workflow, strongly coupling the data acquisition process and the data analysis process. That is, the data acquisition process and the data analysis process are executed in parallel. After the data of one detection unit is collected, the detection unit can be calibrated without waiting for the data of all detection units to be collected before the calibration operation can be performed. This can shorten the system calibration time and improve the system calibration efficiency.

[0066] In addition, each detection unit of the PET system undergoes independent data acquisition and analysis, allowing for independent system calibration of each detection unit, rather than calibrating the entire PET system based on the scanning data of the entire PET system. Therefore, the amount of data required for the calibration algorithm can be reduced, and the calibration efficiency of the system can be further improved while ensuring calibration accuracy.

[0067] In an exemplary embodiment, during the execution of the loop operation in step 206 above, if a target instruction is received, it can determine whether the current detection unit is the last detection unit to be scanned in the PET system according to the target acquisition instruction. If the current detection unit is not the last detection unit to be scanned in the PET system, the scanning bed can continue to be controlled to move to the next detection unit of the PET system for data acquisition, and the current detection unit of the PET system can be corrected according to the scanning data of the current detection unit to obtain the correction result of the current detection unit.

[0068] When the current detection unit is the last detection unit to be scanned in the PET system, the scanning bed can be left uncontrolled, or the scanning bed can be controlled to move to the target position. The target position can be the original position of the scanning bed, that is, the position of the scanning bed when no imaging scan is performed. At the same time, the current detection unit of the PET system can be calibrated based on the scanning data of the current detection unit (i.e. the last detection unit) to obtain the calibration result of the current detection unit.

[0069] In other words, during the sequential data acquisition process of each detection unit in the PET system, before starting data acquisition for the next detection unit, it's necessary to first determine if the current detection unit, which has already completed data acquisition, is the last detection unit to be scanned in the PET system. If the current detection unit is not the last one to be scanned, it means there are still unscanned detection units. In this case, scanning of the next detection unit continues, and a calibration operation for the current detection unit is performed simultaneously. This process is repeated to ensure that the calibration operation for the previous detection unit is performed synchronously each time the next detection unit is scanned. For example, when scanning the second detection unit, the first detection unit is calibrated; when scanning the third detection unit, the second detection unit is calibrated; when scanning the fourth detection unit, the third detection unit is calibrated, and so on.

[0070] If the current detection unit that has completed data acquisition is the last detection unit to be scanned in the PET system, it means that all detection units in the PET system have completed data acquisition operations. At this point, the data acquisition task can be ended. At the same time, with the current detection unit having completed data acquisition, the current detection unit of the PET system can be calibrated based on the scanning data of the current detection unit. After the calibration is completed, the calibration result corresponding to the last detection unit of the PET system can be obtained.

[0071] Furthermore, after completing data acquisition and calibration of all detection units in the PET system, the calibration results for each detection unit can be obtained. These calibration results can then be statistically analyzed to obtain the overall calibration result for the entire PET system. For example, the calibration results for each detection unit can be statistically merged to obtain the final calibration result for the entire PET system. For instance, if the PET system includes a first, second, and third detection unit, the calibration results for the first, second, and third detection units can be combined to obtain the final calibration result for the entire PET system.

[0072] In this embodiment, during multi-bed scanning of the PET system, each detection unit of the PET system is scanned sequentially, and system calibration is performed simultaneously on the previous detection unit while scanning each detection unit. That is, if it is determined that the current detection unit that has completed data acquisition is not the last detection unit to be scanned, data acquisition continues on the next detection unit, and system calibration is performed on the current detection unit simultaneously. If it is determined that the current detection unit that has completed data acquisition is the last detection unit to be scanned, it means that data acquisition for all detection units of the PET system has been completed. At this point, only the last detection unit needs to be calibrated based on the scan data obtained from the last scan. Finally, the calibration results of each detection unit are statistically analyzed to obtain the final calibration result of the entire PET system. Using this method, multi-bed data acquisition of the PET system can be performed simultaneously, and detection unit calibration can be performed based on the acquired data, without waiting for all detection units to complete data acquisition before performing calibration operations for the entire system. This can shorten the system calibration time and improve the system calibration efficiency.

[0073] In one exemplary embodiment, such as Figure 3 As shown, step 204 above involves the scanning data of the current detection unit. The acquisition method for this scanning data can include steps 302 to 304. Wherein:

[0074] Step 302: After completing the data acquisition of the current detection unit of the PET system, acquire the scanning data of the PET system.

[0075] Typically, during multi-bed scanning of a PET system, the scanning bed moves the radiation source to the location corresponding to a specific detection unit within the PET system, enabling scanning of that unit. It's important to note that during the scanning of a specific detection unit, the PET system scans the radiation source. Based on the line of response (LOR) connecting the photon pairs detected by the detector, not only the crystal module within that corresponding detection unit receives the radiation source's scan data, but also the crystal modules in other detection units.

[0076] In addition, each crystal module can receive not only single-event data from the radiation source, but also coincidence event data emitted at 180° to each other from an annihilation event.

[0077] Step 304: Filter the scanning data of the PET system by single-event data and / or coincident event data of the current detection unit to obtain the scanning data of the current detection unit.

[0078] The scanning data of the current detection unit may include single-event data of each crystal module in the current detection unit, and / or coincidence event data of each crystal module in the current detection unit; that is, when performing system calibration, system calibration can be performed based on the single-event data of each crystal module, or based on the coincidence event data of each crystal module, or a comprehensive system calibration can be performed by combining the single-event data and coincidence event data of each crystal module.

[0079] Based on this, for each detection unit, given the acquisition of scan data from all crystal modules in the PET system, the scan data corresponding to the current detection unit can be filtered out from the scan data, including single-event data and / or coincidence event data of the current detection unit. In practical applications, it can be determined whether the data required for calibration is single-event data, coincidence event data, or a combination of single-event and coincidence event data, based on specific calibration requirements. Then, the required calibration data corresponding to the current detection unit can be filtered out from the scan data.

[0080] In this embodiment, after completing the data acquisition of the current detection unit of the PET system, the scanning data of the PET system is obtained. The scanning data of the PET system is then filtered for single-event data and / or coincidence-event data of the current detection unit to obtain the scanning data of the current detection unit. That is, when performing system calibration of the current detection unit of the PET system based on the scanning data of the current detection unit, it is necessary to first filter the scanning data corresponding to the current detection unit from the scanning data of all detection units in the PET system before calibrating the current detection unit based on its scanning data. This improves the accuracy of local calibration of the PET system.

[0081] In one exemplary embodiment, such as Figure 4 As shown, step 204 above, which involves calibrating the PET system based on the scanning data of the current detection unit to obtain the calibration result corresponding to the current detection unit, may include steps 402 to 404. Wherein:

[0082] Step 402: Preprocess the scanning data of the current detection unit to obtain the processed scanning data of the current detection unit.

[0083] For example, when selecting the scan data corresponding to the current detection unit from the scan data of all detection units in the PET system, before calibrating the current detection unit of the PET system based on the scan data of the current detection unit, relevant preprocessing operations can be performed on the scan data of the current detection unit to obtain scan data that meets preset conditions, thereby improving the system calibration efficiency and system calibration accuracy. For example, preset conditions may include, but are not limited to, processing conditions related to data quality, processing conditions related to data format, etc. Correspondingly, preprocessing operations may include, but are not limited to, one or more data processing operations related to data quality, one or more data processing operations related to data format, etc.; for example, noise reduction, averaging, smoothing, interpolation, format conversion, etc., of the scan data; the specific implementation of the preprocessing operations is not specifically limited in the embodiments of this application.

[0084] Step 404: Using a preset calibration algorithm, the current detection unit of the PET system is calibrated based on the processed scan data of the current detection unit to obtain the calibration result of the current detection unit.

[0085] Among them, the preset correction algorithms used for single-event data and coincident event data can be different. That is, single-event data has a corresponding correction algorithm, and coincident event data has a corresponding correction algorithm.

[0086] For example, when the scanning data of the current detection unit includes single-event data, a position correction algorithm can be first used to correct the crystal position of the current detection unit of the PET system based on the processed scanning data of the current detection unit, obtaining an intermediate correction result. Then, an energy correction algorithm is used to correct the energy of the current detection unit of the PET system based on the intermediate correction result and the processed scanning data of the current detection unit, obtaining the correction result of the current detection unit. In other words, the correction algorithm corresponding to single-event data can include both a position correction algorithm and an energy correction algorithm. First, based on the position correction algorithm and the single-event data of the current detection unit, the position of each crystal module within the current detection unit is corrected. Then, based on the energy correction algorithm, the single-event data of the current detection unit, and the position correction result, the energy of each crystal module within the current detection unit is corrected, obtaining the correction result of the current detection unit. The correction result of the current detection unit can include the correction results of each crystal module within the current detection unit.

[0087] For example, when the scan data of the current detection unit includes coincidence event data, a preset correction algorithm can be used to perform crystal position correction, energy correction, and time-of-flight correction on the current detection unit of the PET system based on the processed scan data of the current detection unit, thereby obtaining the correction result of the current detection unit. In other words, for coincidence events, a comprehensive correction algorithm can be used to comprehensively correct the crystal position, energy, and time-of-flight of the current detection unit of the PET system.

[0088] In this embodiment, the scanning data of the current detection unit is first preprocessed to obtain the processed scanning data of the current detection unit. Then, a preset correction algorithm is used to correct the current detection unit of the PET system based on the processed scanning data of the current detection unit, resulting in the correction result of the current detection unit. That is, in this embodiment, before correcting the current detection unit based on its scanning data, the collected scanning data of the current detection unit is preprocessed, and then the current detection unit is corrected based on the preprocessed scanning data corresponding to the current detection unit. This method can improve the accuracy of local correction of the PET system.

[0089] The calibration method for the aforementioned PET system will be described in detail below, taking a specific application scenario. Taking a medical system including a PET system as an example, where the PET system includes a long-axis PET system, and the long-axis PET system comprises three detection units (such as...) Figure 5 In the case of U0, U1, and U2 shown, calibrating the long-axis PET system may include the following steps:

[0090] Step 1: Control the scanning bed to move to the U0 detection unit of the long-axis PET system and collect the scanning data corresponding to the U0 detection unit.

[0091] The scan data corresponding to the U0 detection unit may include single-event data within the U0 detection unit and / or coincidence event data within the U0 detection unit. For example, scan data of each crystal module within the detector can be acquired first after the PET system scans the radiation source; then, scan data corresponding to each crystal module within the U0 detection unit can be selected from the scan data. The coincidence event data within the U0 detection unit may include coincidence event data U0-U0 within U0, coincidence event data U0-U1 between U0 and U1, and coincidence event data U0-U2 between U0 and U2.

[0092] In addition, moving the scanning bed to the U0 detection unit of the long-axis PET system means that the radiation source on the scanning bed is moved to the middle position of the U0 detection unit.

[0093] Step 2: After the data acquisition of the U0 detection unit is completed, control the scanning bed to move to the U1 detection unit of the long-axis PET system and acquire the scanning data corresponding to the U1 detection unit; at this time, perform the step of calibrating the U0 detection unit of the long-axis PET system based on the scanning data corresponding to the U0 detection unit in parallel, and obtain the calibration result of the U0 detection unit.

[0094] Step 3: After the data acquisition of the U1 detection unit is completed, control the scanning bed to move to the U2 detection unit of the long-axis PET system and acquire the corresponding scanning data of the U2 detection unit; at this time, perform the step of calibrating the U1 detection unit of the long-axis PET system based on the scanning data corresponding to the U1 detection unit in parallel, and obtain the calibration result of the U1 detection unit.

[0095] It should be noted that if the data acquisition and calibration processes take different amounts of time, and the data acquisition of the U1 detection unit is completed while the calibration process of the U0 detection unit is not yet finished, the data acquisition process of the U2 detection unit can continue, and the calibration process of the U1 detection unit can be executed after the calibration process of the U0 detection unit is completed.

[0096] Step 4: After the data acquisition of the U2 detection unit is completed and the calibration process of the U1 detection unit is finished, the U2 detection unit of the long axis PET system is calibrated based on the scanning data corresponding to the U2 detection unit, and the calibration result of the U2 detection unit is obtained.

[0097] Step 5: Combine the calibration results of the U0 detection unit, the U1 detection unit, and the U2 detection unit to obtain the calibration results corresponding to the long-axis PET system.

[0098] In one exemplary embodiment, after calibrating the PET system, an imaging scan of the object to be scanned can be performed based on the calibrated PET system; such as Figure 6 As shown, the above method may further include steps 602 to 604, wherein...

[0099] Step 602: Control the PET system to perform a PET scan on the object to be scanned, and obtain the scan data of the object to be scanned.

[0100] Step 604: Based on the calibration results and scanning data of the PET system, image reconstruction is performed to obtain the PET image of the object to be scanned.

[0101] For example, after calibrating the PET system, the calibration result of the PET system can be stored in the PET system in the form of a configuration file, which includes parameter information such as the position, flight time and energy of each crystal module of the detector; based on the parameters in the configuration file, the scanning data of the PET scan of the object to be scanned through the PET system can be used to reconstruct the image, thereby obtaining the PET image of the object to be scanned.

[0102] In this embodiment, PET imaging scanning is performed using a calibrated PET system, which can improve the quality of PET scan images.

[0103] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0104] Based on the same inventive concept, this application also provides a PET system calibration apparatus for implementing the calibration method for the PET system described above. The solution provided by this apparatus is similar to the implementation described in the above method; therefore, the specific limitations in one or more embodiments of the PET system calibration apparatus provided below can be found in the limitations of the PET system calibration method described above, and will not be repeated here.

[0105] In one exemplary embodiment, such as Figure 7As shown, a calibration device for a PET system is provided. The PET system includes a scanning cavity and a scanning bed. The scanning cavity includes multiple detection units arranged along the axial direction, and the scanning bed can move in and out of the scanning cavity along the axial direction. The device includes: an acquisition module 702 and a calibration module 704, wherein:

[0106] The acquisition module 702 is used to acquire the target acquisition command; the target acquisition command is used to indicate that the data acquisition of the current detection unit of the PET system has been completed.

[0107] The calibration module 704 is used to control the scanning bed to move to the next detection unit of the PET system for data acquisition according to the target acquisition command, and to calibrate the PET system according to the scanning data of the current detection unit to obtain the calibration result corresponding to the current detection unit; to take the next detection unit as the new current detection unit, and to repeatedly execute the step of acquiring the target acquisition command until the calibration results of all detection units are obtained; and to obtain the calibration result of the PET system based on the calibration results of all detection units; wherein, moving the scanning bed to the next detection unit of the PET system is used to characterize the movement of the radiation source phantom set on the scanning bed to the preset position corresponding to the next detection unit.

[0108] In one embodiment, the calibration module 704 is specifically used to perform statistical analysis on the calibration results of all detection units to obtain the calibration results of the PET system.

[0109] In one embodiment, the device further includes:

[0110] The acquisition module is used to acquire the scanning data of the PET system after completing the data acquisition of the current detection unit of the PET system;

[0111] The filtering module is used to filter the scanning data of the PET system by single-event data and / or coincident event data of the current detection unit to obtain the scanning data of the current detection unit.

[0112] In one embodiment, the correction module 704 includes:

[0113] The preprocessing unit is used to preprocess the scan data of the current detection unit to obtain the processed scan data of the current detection unit.

[0114] The calibration unit is used to calibrate the current detection unit of the PET system based on the processed scan data of the current detection unit using a preset calibration algorithm, and obtain the calibration result of the current detection unit.

[0115] In one embodiment, the scan data of the current detection unit includes single-event data. A correction unit is used to perform crystal position correction on the current detection unit of the PET system based on the processed scan data of the current detection unit using a position correction algorithm to obtain an intermediate correction result; and to perform energy correction on the current detection unit of the PET system based on the intermediate correction result and the processed scan data of the current detection unit using an energy correction algorithm to obtain a correction result of the current detection unit.

[0116] In one embodiment, the scan data of the current detection unit includes coincidence event data. A correction unit is used to perform crystal position correction, energy correction, and time-of-flight correction on the current detection unit of the PET system based on the processed scan data of the current detection unit using a preset correction algorithm, so as to obtain the correction result of the current detection unit.

[0117] In one embodiment, the device further includes:

[0118] The scanning module is used to control the PET system to perform PET scanning on the object to be scanned, and obtain the scan data of the object to be scanned;

[0119] The reconstruction module is used to reconstruct images based on the calibration results and scan data of the PET system to obtain PET images of the object to be scanned.

[0120] Each module in the calibration device of the aforementioned PET system can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in hardware within or independently of the processor in a computer device, or stored in software within the memory of a computer device, so that the processor can call and execute the corresponding operations of each module.

[0121] In one exemplary embodiment, a computer device is provided, which may be a medical scanning device, and its internal structure diagram may be as follows: Figure 8As shown, this computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operating system and computer programs in the non-volatile storage media to run. The database stores scan data from various detection units of the medical system acquired during calibration. The I / O interfaces are used for information exchange between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a calibration method for a PET system.

[0122] Those skilled in the art will understand that Figure 8 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0123] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the calibration method for the PET system in any of the above embodiments.

[0124] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the calibration method for the PET system in any of the above embodiments.

[0125] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of the calibration method for the PET system in any of the above embodiments.

[0126] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0127] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data analysis logic devices, etc., and are not limited to these.

[0128] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0129] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A calibration method for a PET system, the PET system comprising a scanning cavity and a scanning bed, the scanning cavity comprising a plurality of detection units arranged along an axial direction, the scanning bed being capable of entering and exiting the scanning cavity along the axial direction, characterized in that, The method includes: Obtain the target acquisition instruction; the target acquisition instruction is used to indicate that data acquisition of the current detection unit of the PET system has been completed. According to the target acquisition command, the scanning bed is controlled to move to the next detection unit of the PET system to acquire data, and the current detection unit of the PET system is calibrated according to the scanning data of the current detection unit to obtain the calibration result of the current detection unit; The next detection unit is used as the new current detection unit, and the step of acquiring the target acquisition command is executed repeatedly until the calibration results of all detection units are obtained; based on the calibration results of all detection units, the calibration result of the PET system is obtained; wherein, the movement of the scanning bed to the next detection unit of the PET system is used to characterize the movement of the radiation source phantom set on the scanning bed to the preset position corresponding to the next detection unit.

2. The method according to claim 1, characterized in that, The calibration result of the PET system, obtained based on the calibration results of all the detection units, includes: The calibration results of all the detection units are statistically analyzed to obtain the calibration results of the PET system.

3. The method according to claim 1, characterized in that, The method further includes: After completing the data acquisition of the current detection unit of the PET system, acquire the scanning data of the PET system; The scanning data of the PET system is filtered by single-event data and / or coincident event data of the current detection unit to obtain the scanning data of the current detection unit.

4. The method according to claim 1, characterized in that, The step of calibrating the current detection unit of the PET system based on the scanning data of the current detection unit to obtain the calibration result of the current detection unit includes: The scan data of the current detection unit is preprocessed to obtain the processed scan data of the current detection unit; A preset calibration algorithm is used to calibrate the current detection unit of the PET system based on the processed scan data of the current detection unit, thereby obtaining the calibration result of the current detection unit.

5. The method according to claim 4, characterized in that, The scanning data of the current detection unit includes single-event data. A preset correction algorithm is used to correct the current detection unit of the PET system based on the processed scanning data, resulting in a correction result for the current detection unit, including: A position correction algorithm is used to correct the crystal position of the current detection unit of the PET system based on the processed scan data of the current detection unit, and an intermediate correction result is obtained. An energy correction algorithm is used to perform energy correction on the current detection unit of the PET system based on the intermediate correction results and the processed scan data of the current detection unit, so as to obtain the correction result of the current detection unit.

6. The method according to claim 4, characterized in that, The scanning data of the current detection unit includes coincidence event data. A preset correction algorithm is used to correct the current detection unit of the PET system based on the processed scanning data, resulting in a correction result for the current detection unit, including: Using a preset correction algorithm, the crystal position, energy, and time-of-flight corrections of the current detection unit of the PET system are performed based on the processed scan data of the current detection unit, thereby obtaining the correction result of the current detection unit.

7. The method according to any one of claims 1 to 6, characterized in that, The method further includes: The PET system is controlled to perform a PET scan on the object to be scanned, thereby obtaining the scan data of the object to be scanned. Based on the calibration results of the PET system and the scanning data, image reconstruction is performed to obtain the PET image of the object to be scanned.

8. A calibration apparatus for a PET system, the PET system comprising a scanning cavity and a scanning bed, the scanning cavity comprising a plurality of detection units arranged along an axial direction, the scanning bed being capable of entering and exiting the scanning cavity along the axial direction, characterized in that... The device includes: The acquisition module is used to acquire a target acquisition command; the target acquisition command is used to indicate that data acquisition of the current detection unit of the PET system has been completed. The calibration module is used to control the scanning bed to move to the next detection unit of the PET system for data acquisition according to the target acquisition command, and to calibrate the current detection unit of the PET system according to the scanning data of the current detection unit to obtain the calibration result of the current detection unit; to take the next detection unit as the new current detection unit and repeatedly execute the step of acquiring the target acquisition command until the calibration results of all detection units are obtained; and to obtain the calibration result of the PET system based on the calibration results of all detection units; wherein, the movement of the scanning bed to the next detection unit of the PET system is used to indicate that the radiation source phantom set on the scanning bed has moved to the preset position corresponding to the next detection unit.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

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