Sensitivity correction method of SPECT system and computer equipment

Abstract

The invention relates to a sensitivity correction method of an SPECT system and computer equipment, and the method comprises the steps: determining a mapping relation between a correction parameter of a target system and a system state; a first energy response of the target system in a first time period and a second energy response of the target system in a second time period are obtained, the target system is in a first state in the first time period, and the target system is in a second state in the second time period; determining a current system state change of the second state relative to the first state according to a comparison result of the first energy response and the second energy response; and correcting the sensitivity of the target system based on the mapping relation and the current system state change. Through the method and the device, the problem that the sensitivity of the system cannot be accurately corrected to adapt to the continuous change of the system state is solved, the sensitivity of the system is accurately corrected, and the corrected system is ensured to adapt to the continuous change of the system state.

Description

Technical Field

[0001] This application relates to the field of medical imaging technology, and in particular to a sensitivity calibration method and computer equipment for SPECT systems. Background Technology

[0002] Single-photon emission computed tomography (SPECT) is a mature imaging technique in nuclear medicine, widely used in clinical testing. The sensitivity of the SPECT system is closely related to the accuracy of SPECT image quantification; however, due to factors such as detector aging and environmental changes, the system sensitivity varies over time. Therefore, to achieve accurate SPECT image quantification, the system sensitivity needs to be calibrated.

[0003] In existing technologies, measurements are taken of liquid or solid radioactive sources with known radioactivity, and the system sensitivity is periodically calculated and corrected based on the measurement results. However, since the system state and actual system sensitivity change continuously over time, the correction effect of the above method is poor between two sensitivity corrections, meaning it cannot accurately correct the system sensitivity to adapt to the continuous changes in the system state.

[0004] There is currently no effective solution to the problem that related technologies cannot accurately correct the sensitivity of the system to adapt to continuous changes in the system state. Summary of the Invention

[0005] This embodiment provides a sensitivity calibration method and computer device for a SPECT system to solve the problem in related technologies that the sensitivity of the system cannot be accurately calibrated to adapt to continuous changes in the system state.

[0006] Firstly, this embodiment provides a sensitivity calibration method for a SPECT system, the method comprising:

[0007] Determine the mapping relationship between the correction parameters of the target system and the changes in system state;

[0008] The first energy response of the target system during a first time period and the second energy response of the target system during a second time period are obtained; wherein the target system is in a first state during the first time period and in a second state during the second time period;

[0009] Based on the comparison between the first energy response and the second energy response, the current system state change of the second state relative to the first state is determined;

[0010] The sensitivity of the target system is corrected based on the mapping relationship and the current system state changes.

[0011] In some embodiments, determining the mapping relationship between the correction parameters of the target system and the system state changes includes:

[0012] Under different system states, the energy response and sensitivity of the target system are obtained;

[0013] Based on the energy response and sensitivity of the target system, a mapping relationship is constructed between the sensitivity correction factor and the system state change; the sensitivity correction factor is used to correct the sensitivity of the target system.

[0014] In some of these embodiments, the energy response of the target system is represented by a preset function.

[0015] In some embodiments, the mapping relationship is the correspondence between the changes of each target parameter in the preset function and the sensitivity correction factor.

[0016] In some embodiments, determining the mapping relationship between the correction parameters of the target system and the system state changes includes:

[0017] Based on the nuclide type and collimator type in the target system, the mapping relationship between the correction parameter and the system state change is selected from a preset mapping relationship library.

[0018] In some embodiments, obtaining the first energy response of the target system during a first time period and the second energy response of the target system during a second time period includes:

[0019] The first scan data of the target system within a first time period is acquired, and the first scan data is superimposed to obtain the first energy response.

[0020] The second scan data of the target system during the second time period is acquired, and the second scan data is superimposed to obtain the second energy response.

[0021] In some embodiments, correcting the sensitivity of the target system based on the mapping relationship and the current system state change includes:

[0022] Based on the mapping relationship and the current system state changes, adjust the energy window of the target system;

[0023] Alternatively, the scaling factor of the target system can be corrected based on the mapping relationship and the current system state change.

[0024] Secondly, this embodiment provides a sensitivity calibration method for a SPECT system, the method comprising:

[0025] Obtain the energy response of the target system during the current time period;

[0026] Obtain the reference energy response of the target system;

[0027] Determine whether the energy response in the current time period is the same as the reference energy response;

[0028] In response to a change in the energy response relative to the reference energy response during the current time period, the sensitivity of the target system is corrected; the correction includes energy window correction of the target system and / or correction of the scaling factor of the target system.

[0029] In some embodiments, the correction of the sensitivity of the target system includes:

[0030] Determine the current state of the target system within the current time period, and the reference state of the target system; the reference state corresponds to the reference energy response;

[0031] Based on the comparison between the energy response in the current time period and the reference energy response, the change in the current system state relative to the reference state is determined.

[0032] Determine the mapping relationship between the correction parameters of the target system and the changes in system state;

[0033] Based on the mapping relationship and the current system state changes, the energy window and / or scaling factor of the target system are corrected.

[0034] Thirdly, this embodiment provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described sensitivity correction method for the SPECT system.

[0035] Compared with related technologies, the sensitivity correction method and computer device for the SPECT system provided in this embodiment determine the mapping relationship between the correction parameters of the target system and the system state; obtain the first energy response of the target system in a first time period and the second energy response of the target system in a second time period; wherein, the target system is in a first state in the first time period and in a second state in the second time period; determine the current system state change of the second state relative to the first state based on the comparison result of the first energy response and the second energy response; furthermore, based on the mapping relationship and the current system state change, the sensitivity of the target system is corrected, solving the problem that the sensitivity of the system cannot be accurately corrected to adapt to the continuous changes in the system state, realizing accurate correction of the system sensitivity and ensuring that the corrected system adapts to the continuous changes in the system state.

[0036] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0037] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0038] Figure 1 This is a hardware structure block diagram of the terminal device of the sensitivity correction method of the SPECT system provided in an embodiment of this application;

[0039] Figure 2 This is a flowchart of a sensitivity calibration method for a SPECT system provided in an embodiment of this application;

[0040] Figure 3 This is a schematic diagram of the energy response under different states provided in an embodiment of this application;

[0041] Figure 4 This is a schematic diagram of the energy response of a sensitivity-calibrated water model and an average human body provided in an embodiment of this application;

[0042] Figure 5 This is a schematic diagram of the energy window settings under different states provided in an embodiment of this application;

[0043] Figure 6 This is a schematic diagram illustrating the state changes of the energy window setting according to another embodiment of this application;

[0044] Figure 7 This is a schematic diagram illustrating the mapping relationship between the scale factor and energy drift provided in an embodiment of this application;

[0045] Figure 8 This is a flowchart of a sensitivity calibration method for a SPECT system provided in another embodiment of this application;

[0046] Figure 9 This is a flowchart of a sensitivity calibration method for a SPECT system provided in a preferred embodiment of this application;

[0047] Figure 10 This is a structural block diagram of the sensitivity correction device of the SPECT system provided in an embodiment of this application.

[0048] In the diagram: 102, processor; 104, memory; 106, transmission device; 108, input / output device; 10, determination module; 20, acquisition module; 30, comparison module; 40, correction module. Detailed Implementation

[0049] To better understand the purpose, technical solution, and advantages of this application, the application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0050] Unless otherwise defined, the technical or scientific terms used in this application shall have the general meaning as understood by one of ordinary skill in the art to which this application pertains. Words such as “a,” “an,” “an,” “the,” “the,” and “these,” used in this application, do not indicate quantitative limitation and may be singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that comprises a series of steps or modules (units) is not limited to the listed steps or modules (units) but may include steps or modules (units) not listed, or may include other steps or modules (units) inherent to such processes, methods, products, or devices. The terms “connected,” “linked,” and “coupled,” used in this application, are not limited to physical or mechanical connections but may include electrical connections, whether direct or indirect. The term “multiple” used in this application refers to two or more. The "and / or" operator describes the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: A alone, A and B simultaneously, and B alone. Typically, the character " / " indicates that the objects before and after it are in an "or" relationship. The terms "first," "second," and "third," etc., used in this application are merely for distinguishing similar objects and do not represent a specific ordering of the objects.

[0051] The method embodiments provided in this example can be executed on a terminal, computer, or similar computing device. For example, it can run on a terminal. Figure 1This is a hardware structure block diagram of the terminal of the SPECT system sensitivity correction method in this embodiment. For example... Figure 1 As shown, a terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 and a memory 104 for storing data are also included. The processor 102 may be, but is not limited to, a microprocessor (MCU) or a programmable logic device (FPGA). The terminal may also include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that… Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the terminal described above. For example, the terminal may also include components that are larger than... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown are illustrated.

[0052] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the sensitivity correction method of the SPECT system in this embodiment. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0053] The transmission device 106 is used to receive or send data via a network. This network includes a wireless network provided by the terminal's communication provider. In one example, the transmission device 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 106 can be a Radio Frequency (RF) module used for wireless communication with the Internet.

[0054] This embodiment provides a sensitivity calibration method for a SPECT system. Figure 2 This is a flowchart of the sensitivity calibration method of the SPECT system in this embodiment, as follows: Figure 2 As shown, the process includes the following steps:

[0055] Step S210: Determine the mapping relationship between the correction parameters of the target system and the changes in system state.

[0056] Specifically, by changing the detector state of the target system, the system state is altered. Under different system states, the energy response and sensitivity of the target system are acquired. Based on the energy response and sensitivity of the target system, a mapping relationship is constructed between a sensitivity correction factor and the change in system state. The sensitivity correction factor is used to correct the sensitivity of the target system. The detector state can be changed by setting different ambient temperatures, humidity levels, and dust conditions.

[0057] It should be noted that the energy response of the target system to the average human body can reflect changes in the system's state, such as... Figure 3 As shown, Figure 3 (a) and (b) show the energy response curves of the detector in states 1 and 2, respectively. The energy response of the detector to the average human body changes under different system states. The superposition of a large amount of clinical scan data from the SPECT system can be understood as the scan data of the average human body. A certain nuclide typically corresponds to one or more energy peaks. The energy distribution after superimposing a large amount of clinical scan data can approximate the energy response of the detector to the average human body. For example, this can be achieved by superimposing scan data from the same part of multiple subjects, or by superimposing scan data from subjects with similar body mass indices.

[0058] Based on this, a water model simulating the human body or a cylindrical uniform water model is used as the water model for sensitivity correction, so that the energy response of the system detector to the sensitivity correction water model is close to its energy response to the average human body, such as... Figure 4 As shown, curves A and B represent the energy response of the detector to the sensitivity-corrected water model and the energy response of the detector to the average human body, respectively.

[0059] In the process of constructing the mapping relationship, a sensitivity-calibrated water model is used to measure the energy response and sensitivity, so that the system state changes can be reflected through the system's energy response, while ensuring the accuracy of obtaining the energy response and sensitivity.

[0060] Step S220: Obtain the first energy response of the target system in the first time period and the second energy response of the target system in the second time period; wherein the target system is in the first state in the first time period and the target system is in the second state in the second time period.

[0061] Specifically, in the initial stage of using the target system, a sensitivity calibration water phantom is used to pre-calibrate the system's sensitivity. Subsequently, clinical data obtained from actual scans of the target system under different conditions are accumulated to obtain the energy response of the target system under different conditions.

[0062] In the actual scanning process of the target system, the first scan data of the target system within a first time period is acquired. This first scan data includes clinical data corresponding to multiple scans within the first time period. The first scan data is then overlaid to obtain a first energy response. When the system is in a second time period, the second scan data of the target system is acquired. This second scan data includes clinical data corresponding to multiple scans within the second time period. The second scan data is then overlaid to obtain a second energy response. It should be noted that the target system is in a first state during the first time period and in a second state during the second time period. The first and second time periods can correspond to historical time periods and the current time period, respectively.

[0063] Step S230: Based on the comparison result of the first energy response and the second energy response, determine the current system state change of the second state relative to the first state.

[0064] Specifically, using the first energy response as a benchmark, the second energy response is compared with the benchmark to obtain the energy response difference of the target system in different states, reflecting the state changes of the target system. Thus, the clinical data obtained from the target system scan can be used to calibrate and monitor the changes in the system state to determine the current system state change in the second state relative to the first state, that is, the change in the target system state in the second time period compared to the target system state in the first time period.

[0065] Step S240: Based on the mapping relationship and the current system state changes, the sensitivity of the target system is corrected.

[0066] Specifically, based on the mapping relationship between the correction parameters of the target system and the changes in system state, the current correction parameters corresponding to the current changes in system state are determined, and the sensitivity of the target system is corrected using the current correction parameters.

[0067] It should be noted that the above corrections include energy window correction of the target system and correction of the scaling factor of the target system. Energy window correction includes adjusting the center position and width of the energy window, etc.; when correcting the scaling factor of the target system, the count rate of the target system is corrected by setting a reasonable scaling factor while keeping the energy window unchanged.

[0068] To achieve accurate quantitative analysis of SPECT images, measurements are typically performed on liquid or solid radioactive sources with known radioactivity, and the system sensitivity is periodically calculated and calibrated based on the measurement results. However, since the system state and actual system sensitivity change continuously over time, the above method is ineffective between two sensitivity calibrations, meaning it cannot accurately calibrate the system sensitivity to accommodate continuous changes in the system state.

[0069] Compared to existing technologies, this application determines the mapping relationship between the correction parameters of the target system and the system state; obtains the first energy response of the target system in a first time period and the second energy response of the target system in a second time period, wherein the target system is in a first state in the first time period and in a second state in the second time period; determines the current system state change of the second state relative to the first state based on the comparison result of the first energy response and the second energy response; and further, corrects the sensitivity of the target system based on the mapping relationship and the current system state change. Based on this, the energy response of the system detector reflects the system state to establish a mapping relationship between the system correction parameters and the system state change, and the system sensitivity is corrected accordingly based on the actual state change of the system and the mapping relationship. This solves the problem of not being able to accurately correct the system sensitivity to adapt to continuous changes in the system state, significantly extending the correction period, accurately correcting the system sensitivity, and ensuring that the corrected system adapts to continuous changes in the system state.

[0070] In some embodiments, determining the mapping relationship between the correction parameters of the target system and the system state changes in step S210 includes the following steps:

[0071] Step S211: Obtain the energy response and sensitivity of the target system under different system states;

[0072] Step S212: Based on the energy response and sensitivity of the target system, construct the mapping relationship between the sensitivity correction factor and the system state change; the sensitivity correction factor is used to correct the sensitivity of the target system.

[0073] Specifically, by setting different environmental conditions, the system state of the target system is changed. Under different system states, multiple sensitivity measurements are performed using a sensitivity-calibrated water model, and the energy response of the target system under each system state is obtained. The energy response of the system detector to the sensitivity-calibrated water model is close to its energy response to the average human body.

[0074] Furthermore, the average of multiple sensitivities under each system state is calculated as the sensitivity corresponding to that system state, thereby ensuring the accuracy of sensitivity measurement. Since the change in the energy response of the target system to the average human body can reflect the change in system state, a mapping relationship between the sensitivity correction factor and the change in system state is constructed based on the changes in sensitivity and energy response of the target system under different system states. The sensitivity correction factor is used to correct the sensitivity of the target system.

[0075] This embodiment obtains the energy response and sensitivity of the target system, and based on the energy response and sensitivity of the target system, accurately constructs the mapping relationship between the sensitivity correction factor and the system state change.

[0076] In some of these embodiments, the energy response of the target system is represented in the form of a preset function.

[0077] In this embodiment, the changes in the system state are reflected by the energy response of the system detector to the average human body. The energy response of the detector to the average human body can be simplified to a preset function, including a Gaussian function, a double Gaussian function, a composite function composed of a Gaussian function and an exponential function, etc.

[0078] Specifically, based on the energy response curve of the detector to the average human body under each system state, the corresponding function formula for the system state is determined, thereby parameterizing the system state. For example, ... Figure 3 As shown, the energy response in states 1 and 2 is expressed using a Gaussian function. The energy response P(E) in state 1 is as follows:

[0079]

[0080] In equation (1), A represents the peak value of the curve; σ and μ are the standard deviation and mean, respectively.

[0081] The energy response P'(E) in state 2 is as follows:

[0082]

[0083] In equation (2), A' represents the peak value of the curve; σ' and μ' are the standard deviation and mean, respectively.

[0084] In this embodiment, the energy response of the target system is represented in the form of a preset function, thereby parameterizing the system state and facilitating the establishment of subsequent mapping relationships.

[0085] In some embodiments, the mapping relationship is the correspondence between the changes of each target parameter in the preset function and the sensitivity correction factor.

[0086] Specifically, a preset function is used to represent the energy response of the detector to the average human body under each system state, and the function formula corresponding to the system state is obtained. The change of each parameter in the formula reflects the change of the system state.

[0087] For example, a Gaussian function is used to represent the energy response of the detector. Under a certain system state, the energy response is: The target parameters in the formula include the curve peak value A, the standard deviation σ, and the mean μ. Changes in the target parameters A, σ, and μ can reflect changes in the system state. Based on this, by constructing a correspondence between changes in the target parameters and the sensitivity correction factor, a mapping relationship between changes in the system state and the sensitivity correction factor is obtained.

[0088] In this embodiment, by constructing the correspondence between the changes of each target parameter in the preset function and the sensitivity correction factor, the mapping relationship between the system state change and the sensitivity correction factor can be accurately obtained.

[0089] In some embodiments, determining the mapping relationship between the correction parameters of the target system and the system state changes in step S210 includes the following steps:

[0090] Based on the nuclide type and collimator type in the target system, the mapping relationship between the correction parameters and the system state changes is selected from the preset mapping relationship library.

[0091] It should be noted that, since the energy distribution of the superimposed large amount of clinical scan data in this embodiment is approximated as the energy response of the detector to the average human body, the energy response of the detector to the average human body is associated with the nuclide category and the collimator category. Based on different combinations of nuclides and collimators, different mapping relationships can be constructed.

[0092] Specifically, referring to the above-described method for constructing mapping relationships, for different combinations of nuclides and collimators, corresponding mapping relationships between correction parameters and system state changes are constructed to establish a mapping relationship library, storing the different combinations of nuclides and collimators with their corresponding mapping relationships. In practical applications, based on the nuclide and collimator categories in the target system, the corresponding mapping relationship is selected from the preset mapping relationship library as the mapping relationship between the target system state changes and correction parameters.

[0093] In this embodiment, based on the nuclide type and collimator type in the target system, the mapping relationship between the correction parameters and the system state changes is selected from a preset mapping relationship library. This avoids repeatedly performing the mapping relationship construction process for similar or identical systems, reduces correction costs, and improves the efficiency of the preset mapping relationship.

[0094] In some embodiments, step S220, obtaining the first energy response of the target system in a first time period and the second energy response of the target system in a second time period, includes the following steps:

[0095] Step S221: Obtain the first scan data of the target system within the first time period, and perform superposition processing on the first scan data to obtain the first energy response;

[0096] Step S222: Obtain the second scan data of the target system in the second time period, and perform superposition processing on the second scan data to obtain the second energy response.

[0097] Specifically, the first scan data of the target system within the first time period is acquired. The first scan data contains clinical data corresponding to multiple scans of the target system within the first time period. The energy information in the first scan data is superimposed, and the superimposed energy distribution is the first energy response.

[0098] Furthermore, when the system is in the second time period, it acquires the second scan data of the target system. The second scan data contains clinical data corresponding to multiple scans of the target system within the second time period. The energy information in the second scan data is superimposed, and the superimposed energy distribution is the second energy response. Here, the first time period and the second time period can be the historical time period and the current time period, respectively.

[0099] For example, the first scan data within a week is superimposed to obtain the superimposed energy distribution as the first energy response, and the second scan data within the following week is accumulated and superimposed to obtain the superimposed energy distribution as the second energy response.

[0100] It should be noted that, in addition to accumulating clinical scan data according to time periods, data can also be accumulated based on a preset number of scans, such as accumulating data every 50 scans. This embodiment does not limit the method of accumulating clinical scan data.

[0101] In this embodiment, the first scan data of the target system in the first time period is obtained, and the first scan data is superimposed to obtain the first energy response. The second scan data of the target system in the second time period is obtained, and the second scan data is superimposed to obtain the second energy response. In this way, the energy response of the detector under different states can be obtained so as to accurately reflect the changes in the system state, while ensuring the objectivity of using the changes in energy response to reflect the changes in the system state.

[0102] In some embodiments, step S240, which involves correcting the sensitivity of the target system based on the mapping relationship and the current system state change, includes the following steps:

[0103] Step S241: Adjust the energy window of the target system based on the mapping relationship and the current system state changes;

[0104] Step S242, or, based on the mapping relationship and the current system state change, correct the count rate of the target system.

[0105] Specifically, the energy window of a SPECT system is used to select the range of gamma-ray energies received by the detector. The way the energy window is set affects the system's sensitivity. After determining the current system state change, the current correction parameters corresponding to the current system state change are determined by referring to a pre-built mapping relationship between system state changes and correction parameters. These current correction parameters are then used to adjust the energy window of the target system, including setting the center position and width of the energy window. For example... Figure 5 As shown, Figure 5 (a) shows the energy window setting in state 1, and (b) shows the energy window setting in state 2. When the system state changes from state 1 to state 2, or from state 2 to state 1, the energy window setting needs to be adjusted accordingly in order to correct the system sensitivity.

[0106] Furthermore, the count rate of a SPECT system refers to the number of energy events recorded by the detector within a certain time period. When the system's count rate changes, the number of photons received by the detector changes accordingly, causing a corresponding change in the system's sensitivity. Based on this, according to a pre-constructed mapping relationship and the current state change, the current correction parameters corresponding to the current system state change are determined. While keeping the energy window constant, the scale factor is corrected based on the current correction parameters to set a reasonable scale factor, thereby achieving correction of the target system's count rate. Figure 6 As shown, the energy window setting in state 1 is the same as that in state 2, but when the system state changes from state 1 to state 2, or from state 2 to state 1, the scale factor is adjusted accordingly to correct the count rate.

[0107] For count rate correction, it is necessary to pre-establish a mapping relationship between energy drift and scale factor, such as... Figure 7 As shown, when the system state changes, the scale factor corresponding to the system state is selected based on the mapping relationship between energy drift and scale factor to achieve count rate correction.

[0108] This embodiment adjusts the energy window of the target system based on the mapping relationship and changes in the current system state, or corrects the count rate of the target system based on the mapping relationship and changes in the current system state, thereby flexibly realizing the correction of system sensitivity and enabling the target system to be corrected in the optimal way.

[0109] This embodiment also provides a sensitivity calibration method for a SPECT system. Figure 8 This is a flowchart of the sensitivity calibration method of the SPECT system in this embodiment, as follows: Figure 8 As shown, the process includes the following steps:

[0110] Step S810: Obtain the energy response of the target system in the current time period;

[0111] Step S820: Obtain the baseline energy response of the target system;

[0112] Step S830: Determine whether the energy response in the current time period is the same as the reference energy response;

[0113] Step S840: In response to a change in the energy response relative to the reference energy response during the current time period, the sensitivity of the target system is corrected; the correction includes energy window correction of the target system and / or correction of the scaling factor of the target system.

[0114] Specifically, the process involves acquiring scan data from the target system within the current time period. This scan data includes clinical data corresponding to multiple scans conducted by the target system within the current time period. The energy information in the scan data is then overlaid, and the resulting energy distribution represents the energy response within the current time period. For example, scan data accumulated over the past week can be overlaid to obtain the energy distribution for the current time period. Alternatively, data can be accumulated based on a preset number of scans, such as accumulating data every 50 scans.

[0115] It should be noted that in this embodiment, the changes in system state are reflected by the energy response of the system detector to the average human body. The energy response of the detector to the average human body can be simplified to a preset function, including a Gaussian function, a double Gaussian function, a composite function composed of a Gaussian function and an exponential function, etc. In this way, the function formula corresponding to the system state is determined according to the energy response curve of the detector to the average human body under each system state, thereby parameterizing the system state.

[0116] For example, a Gaussian function is used to represent the detector's energy response. Under a certain system state, template parameters such as the peak value, standard deviation, and mean of the energy response function are used to reflect changes in the system state. Based on this, by constructing a correspondence between changes in the target parameters and the sensitivity correction factor, a mapping relationship between changes in the system state and the sensitivity correction factor is obtained.

[0117] Furthermore, a reference energy response of the target system is obtained, which is the energy response information of the target system under a reference state. It is then determined whether the energy response in the current time period is the same as the reference energy response. If the energy response in the current time period changes relative to the reference energy response, the sensitivity of the target system is corrected. In this embodiment, the correction method includes, but is not limited to, energy window correction of the target system and correction of the scaling factor of the target system.

[0118] In this embodiment, the energy response of the target system in the current time period is obtained, the reference energy response of the target system is obtained, and it is determined whether the energy response in the current time period is the same as the reference energy response. If the energy response in the current time period changes relative to the reference energy response, the sensitivity of the target system is corrected. In this way, the reference energy response of the system is used to achieve accurate correction of the system.

[0119] In some embodiments, the sensitivity correction of the target system in step S840 includes the following steps:

[0120] Step S841: Determine the current state of the target system in the current time period, and the reference state of the target system; the reference state corresponds to the reference energy response;

[0121] Step S842: Based on the comparison between the energy response in the current time period and the reference energy response, determine the change in the current system state relative to the reference state.

[0122] Step S843: Determine the mapping relationship between the correction parameters of the target system and the changes in system state;

[0123] Step S844: Based on the mapping relationship and the current system state changes, correct the energy window of the target system and / or the scaling factor of the target system.

[0124] Specifically, the current state of the target system within the current time period and the baseline state of the target system are determined. The baseline state refers to the state of the target system when its energy response is the baseline energy response. The current state of the target system within the current time period is compared with the baseline energy response, and the change in the current system state relative to the baseline state is determined based on the comparison result.

[0125] Furthermore, based on the mapping relationship between the correction parameters of the target system and the system state changes, the correction parameters corresponding to the current system state changes are determined, and the system is corrected using the correction parameters corresponding to the current system state changes. The correction methods include energy window correction of the target system and correction of the scaling factor of the target system.

[0126] Specifically, the energy window of the target system is corrected using correction parameters corresponding to changes in the current system state. The energy window correction method includes setting the center position and width of the energy window. Furthermore, when correcting the scaling factor of the target system, the scaling factor is adjusted based on the correction parameters corresponding to changes in the current system state while keeping the energy window unchanged. This allows for the setting of a reasonable scaling factor, thereby correcting the count rate of the target system.

[0127] This embodiment determines the current state of the target system within the current time period and the baseline state of the target system. Based on the comparison between the energy response within the current time period and the baseline energy response, it determines the change in the current system state relative to the baseline state. Then, it determines the mapping relationship between the correction parameters of the target system and the system state change. Based on the mapping relationship and the change in the current system state, it corrects the energy window and / or the scaling factor of the target system. Thus, it corrects the system according to the change in the current system state relative to the baseline state, and can reasonably select the appropriate correction method according to the actual application scenario.

[0128] The present embodiment will now be described and illustrated through preferred embodiments.

[0129] Figure 9 This is a flowchart of the sensitivity calibration method of the SPECT system according to a preferred embodiment, as shown below. Figure 9 As shown, the sensitivity calibration method for this SPECT system includes the following steps:

[0130] Step S910: Obtain the energy response and sensitivity of the target system under different system states;

[0131] Step S920: Based on the energy response and sensitivity of the target system, construct the mapping relationship between the sensitivity correction factor and the system state change.

[0132] Step S930: Obtain the first scan data of the target system within the first time period, and perform superposition processing on the first scan data to obtain the first energy response; the target system is in the first state during the first time period.

[0133] Step S940: Acquire the second scan data of the target system during the second time period, and perform superposition processing on the second scan data to obtain the second energy response; the target system is in the second state during the second time period.

[0134] Step S950: Based on the comparison result between the first energy response and the second energy response, determine the current system state change of the second state relative to the first state;

[0135] Step S960: Adjust the energy window of the target system based on the mapping relationship and the current system state changes;

[0136] Step S970, or, based on the mapping relationship and the current system state change, correct the scaling factor of the target system.

[0137] In this embodiment, the energy response and sensitivity of the target system are obtained under different system states, and a mapping relationship between the sensitivity correction factor and the system state change is constructed based on the energy response and sensitivity of the target system.

[0138] Furthermore, during the first time period, the first scan data of the target system in the first state is acquired, and the first scan data is superimposed to obtain the first energy response. During the second time period, the second scan data of the target system in the second state is acquired, and the second scan data is superimposed to obtain the second energy response. Thus, based on the comparison between the first energy response and the second energy response, the current system state change in the second state relative to the first state can be determined, thereby accurately reflecting the change in system state.

[0139] Subsequently, based on the mapping relationship and the current system state changes, the energy window of the target system is adjusted, or the scaling factor of the target system is corrected based on the mapping relationship and the current system state changes. This solves the problem of not being able to accurately correct the sensitivity of the system to adapt to the continuous changes in the system state, and realizes accurate correction of the system sensitivity, ensuring that the corrected system adapts to the continuous changes in the system state.

[0140] It should be noted that the steps shown in the above process or in the flowchart of the accompanying figures can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0141] This embodiment also provides a sensitivity correction device for a SPECT system, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. The terms "module," "unit," "subunit," etc., used below refer to combinations of software and / or hardware that perform a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0142] Figure 10 This is a structural block diagram of the sensitivity correction device of the SPECT system in this embodiment, as shown below. Figure 10 As shown, the device includes: a determining module 10, an acquiring module 20, a comparing module 30, and a calibration module 40;

[0143] Module 10 is used to determine the mapping relationship between the correction parameters of the target system and the changes in system state;

[0144] The acquisition module 20 is used to acquire the first energy response of the target system in a first time period and the second energy response of the target system in a second time period; wherein the target system is in a first state in the first time period and the target system is in a second state in the second time period.

[0145] The comparison module 30 is used to determine the current system state change of the second state relative to the first state based on the comparison result of the first energy response and the second energy response.

[0146] The correction module 40 is used to correct the sensitivity of the target system based on the mapping relationship and the current system state changes.

[0147] The apparatus provided in this embodiment determines the mapping relationship between the correction parameters of the target system and the changes in system state; it acquires the first energy response of the target system in a first time period and the second energy response of the target system in a second time period, wherein the target system is in a first state in the first time period and in a second state in the second time period; based on the comparison result of the first energy response and the second energy response, it determines the current system state change of the second state relative to the first state; further, based on the mapping relationship and the current system state change, it corrects the sensitivity of the target system, solving the problem that the sensitivity of the system cannot be accurately corrected to adapt to the continuous changes in system state, and realizing accurate correction of the sensitivity of the system to ensure that the corrected system adapts to the continuous changes in system state.

[0148] In some embodiments, the determining module 10 is further configured to acquire the energy response and sensitivity of the target system under different system states; and based on the energy response and sensitivity of the target system, construct a mapping relationship between the sensitivity correction factor and the system state change.

[0149] In some embodiments, the determining module 10 is further configured to select a mapping relationship between the correction parameter and the system state change from a preset mapping relationship library based on the nuclide type and collimator type in the target system.

[0150] In some embodiments, the acquisition module 20 is further configured to acquire first scan data of the target system in a first time period, perform superposition processing on the first scan data to obtain a first energy response; acquire second scan data of the target system in a second time period, perform superposition processing on the second scan data to obtain a second energy response.

[0151] In some embodiments, the correction module 40 is also used to adjust the energy window of the target system based on the mapping relationship and the current system state change; or, to correct the count rate of the target system based on the mapping relationship and the current system state change.

[0152] It should be noted that the above modules can be functional modules or program modules, and can be implemented through software or hardware. For modules implemented through hardware, the above modules can reside in the same processor; or the above modules can be located in different processors in any combination.

[0153] This embodiment also provides a computer device, including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the steps in any of the above method embodiments.

[0154] Optionally, the computer device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor and the input / output device is connected to the processor.

[0155] Optionally, in this embodiment, the processor can be configured to perform the following steps via a computer program:

[0156] S1, determine the mapping relationship between the correction parameters of the target system and the changes in system state;

[0157] S2, acquire the first energy response of the target system in the first time period and the second energy response of the target system in the second time period; wherein, the target system is in the first state in the first time period and the target system is in the second state in the second time period;

[0158] S3, Based on the comparison results of the first energy response and the second energy response, determine the current system state change of the second state relative to the first state;

[0159] S4, based on the mapping relationship and the current system state changes, corrects the sensitivity of the target system.

[0160] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementations, and will not be repeated in this embodiment.

[0161] Furthermore, in conjunction with the sensitivity calibration method for the SPECT system provided in the above embodiments, this embodiment can also provide a storage medium for implementation. This storage medium stores a computer program; when executed by a processor, the computer program implements any of the sensitivity calibration methods for the SPECT system described in the above embodiments.

[0162] It should be understood that the specific embodiments described herein are merely illustrative of the application and not intended to limit it. All other embodiments derived by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0163] Obviously, the accompanying drawings are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar situations based on these drawings without any creative effort. Furthermore, it is understood that although the work done in this development process may be complex and lengthy, for those skilled in the art, certain design, manufacturing, or production modifications made based on the technical content disclosed in this application are merely conventional technical means and should not be considered as insufficient disclosure of this application.

[0164] The term "embodiment" in this application refers to a specific feature, structure, or characteristic described in connection with an embodiment that may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily imply the same embodiment, nor does it imply that it is mutually exclusive with or independent of other embodiments. It will be clearly or implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0165] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of patent protection. 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 scope of protection of this application. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A sensitivity calibration method for a SPECT system, characterized in that, The method includes: Determine the mapping relationship between the correction parameters of the target system and the changes in system state; The first energy response of the target system during a first time period and the second energy response of the target system during a second time period are obtained; wherein the target system is in a first state during the first time period and in a second state during the second time period; Based on the comparison between the first energy response and the second energy response, the current system state change of the second state relative to the first state is determined; The sensitivity of the target system is corrected based on the mapping relationship and the current system state changes.

2. The sensitivity calibration method for the SPECT system according to claim 1, characterized in that, Determining the mapping relationship between the correction parameters of the target system and the changes in system state includes: Under different system states, the energy response and sensitivity of the target system are obtained; Based on the energy response and sensitivity of the target system, a mapping relationship is constructed between the sensitivity correction factor and the system state change; the sensitivity correction factor is used to correct the sensitivity of the target system.

3. The sensitivity calibration method for the SPECT system according to claim 2, characterized in that, The energy response of the target system is represented by a preset function.

4. The sensitivity calibration method for the SPECT system according to claim 3, characterized in that, The mapping relationship is the correspondence between the changes of each target parameter in the preset function and the sensitivity correction factor.

5. The sensitivity calibration method for the SPECT system according to claim 1, characterized in that, Determining the mapping relationship between the correction parameters of the target system and the changes in system state includes: Based on the nuclide type and collimator type in the target system, the mapping relationship between the correction parameter and the system state change is selected from a preset mapping relationship library.

6. The sensitivity calibration method for the SPECT system according to claim 1, characterized in that, The acquisition of the first energy response of the target system in a first time period and the second energy response of the target system in a second time period includes: The first scan data of the target system within a first time period is acquired, and the first scan data is superimposed to obtain the first energy response. The second scan data of the target system during the second time period is acquired, and the second scan data is superimposed to obtain the second energy response.

7. The sensitivity calibration method for the SPECT system according to claim 1, characterized in that, The step of correcting the sensitivity of the target system based on the mapping relationship and the current system state change includes: Based on the mapping relationship and the current system state changes, adjust the energy window of the target system; Alternatively, the scaling factor of the target system can be corrected based on the mapping relationship and the current system state change.

8. A sensitivity calibration method for a SPECT system, characterized in that, The method includes: Obtain the energy response of the target system during the current time period; Obtain the reference energy response of the target system; Determine whether the energy response in the current time period is the same as the reference energy response; In response to a change in the energy response relative to the reference energy response during the current time period, the sensitivity of the target system is corrected; the correction includes energy window correction of the target system and / or correction of the scaling factor of the target system.

9. The sensitivity calibration method for the SPECT system according to claim 8, characterized in that, The correction of the sensitivity of the target system includes: Determine the current state of the target system within the current time period, and the reference state of the target system; the reference state corresponds to the reference energy response; Based on the comparison between the energy response in the current time period and the reference energy response, the change in the current system state relative to the reference state is determined. Determine the mapping relationship between the correction parameters of the target system and the changes in system state; Based on the mapping relationship and the current system state changes, the energy window and / or scaling factor of the target system are corrected.

10. A computer device, comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to run the computer program to perform the steps of the sensitivity correction method for the SPECT system according to any one of claims 1 to 9.

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