SPECT detector correction method, device, equipment and medium

Abstract

The embodiment of the invention relates to the technical field of photon imaging, and discloses an SPECT detector correction method, device, equipment and medium, and the method comprises the steps: carrying out the passive correction of an SPECT detector according to a preset passive energy correction target peak channel address table, so as to obtain a passive energy correction table; the passive energy correction table is used for performing energy correction on gamma photons acted by the SPECT detector when the SPECT detector performs imaging. According to the SPECT detector correction method, device and equipment and the medium, on one hand, correction can be carried out without professionals, doctors or technicians and other users can also carry out correction on the SPECT detector, manpower resources are saved, and on the other hand, ray hazards caused by radioactive sources during correction can be avoided.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of photon imaging, and particularly to a SPECT detector calibration method, device, equipment and medium. Background Art

[0002] Single-Photon Emission Computed Tomography (SPECT) is a technology for tomographic imaging of radioactive drugs (such as 99mTc) that emit only a single γ photon per decay. Discrete pixel-type SPECT detectors are usually composed of several methods such as array semiconductor radiation detectors, array scintillators, and optoelectronic devices. Each independent pixel detector in each array module can directly perform radiation detection.

[0003] Energy consistency refers to the consistency of the energy response of the SPECT detector to incident γ photons at different positions during SPECT or SPECT-CT acquisition. It is usually represented by the difference in the energy peak positions of the responses of each pixel to the uniform flood source radiation field. Poor energy consistency will cause distortion and distortion in the images acquired by SPECT.

[0004] The main factors that cause the deterioration of the energy consistency of the SPECT detector are: the output amplitude of each pixel detector changes; the environmental temperature changes, resulting in a change in the detector output amplitude; the aging of the semiconductor radiation detector or the poor coupling of the array scintillator + optoelectronic device will also cause a change in the energy response of the detector to the ray, etc.

[0005] In the related art, an energy calibration table corresponding to each pixel is generated by using a radiation source (such as 99mTc, 57Co, etc.) to calibrate the detector, and the γ photons collected are energy-corrected through the calibration table. However, this method requires the use of a radiation source, and a radiation source must be available for each calibration. At the same time, there are requirements for the activity and positioning of the radiation source, and professional technical operators, usually technical personnel of the manufacturer, are required to operate. In the actual use process in hospitals, doctors or technicians often do not have the relevant professional ability to perform calibration, and relevant professionals need to be invited to perform the calibration operation. Moreover, the radiation source poses a radiation hazard to the environment and operators during calibration. Summary of the Invention

[0006] The object of the present invention is to provide at least one SPECT detector calibration method, device, equipment and medium, which can at least solve the problems that a radiation source needs to be continuously used to calibrate the SPECT detector, resulting in the need for professional personnel to perform the calibration and the use of the radiation source causing radiation hazards. It can at least achieve using the radiation source only during installation and commissioning, and during the normal use of the equipment, the calibration of the SPECT detector can be achieved without the radiation source.

[0007] To solve the above technical problems, at least one embodiment of the present invention provides a SPECT detector calibration method. The SPECT detector has a corresponding preset passive energy calibration target peak channel address table, and the preset passive energy calibration target peak channel address table is obtained from a preset source energy calibration table. The method includes:

[0008] Performing passive calibration on the SPECT detector according to the preset passive energy calibration target peak channel address table to obtain a passive energy calibration table. The passive energy calibration table is used to perform energy calibration on the γ photons acting on the SPECT detector when the SPECT detector images.

[0009] At least one embodiment of the present invention also provides a SPECT detector calibration device. The SPECT detector has a corresponding preset passive energy calibration target peak channel address table, and the preset passive energy calibration target peak channel address table is obtained from a preset source energy calibration table. The device includes:

[0010] A calibration module that performs passive calibration on the SPECT detector according to the preset passive energy calibration target peak channel address table to obtain a passive energy calibration table. The passive energy calibration table is used to perform energy calibration on the γ photons acting on the SPECT detector when the SPECT detector images.

[0011] At least one embodiment of the present invention also provides an electronic device, including: at least one processor; and a memory communicatively connected to the at least one processor. Wherein, the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the above SPECT detector calibration method.

[0012] At least one embodiment of the present invention also provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the above SPECT detector calibration method is implemented.

[0013] The SPECT detector calibration method provided by the embodiments of the present invention only generates a preset energy calibration table with a radiation source during equipment installation; then, a preset energy calibration target peak channel address table is generated through the preset energy calibration table with a radiation source during equipment installation; after that, passive energy calibration is performed through the preset energy calibration target peak channel address table to generate a passive energy calibration table, and passive energy calibration without using a radiation source can be completed. During the normal use of the equipment in the present invention, passive energy calibration can be completed only by performing passive energy calibration through the preset energy calibration target peak channel address table to generate a passive energy calibration table, and a radiation source is not required for this process. On the one hand, calibration does not need to be carried out by professionals, and users such as doctors or technicians can also perform calibration, saving human resources. On the other hand, the radiation hazard caused by the radiation source during calibration can be avoided. Brief Description of the Drawings

[0014] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings, and these exemplary illustrations do not limit the embodiments.

[0015] Figure 1 is a flowchart of the SPECT detector calibration method provided by an embodiment of the present invention;

[0016] Figure 2 is an energy spectrum diagram of the SPECT detector before passive calibration provided by an embodiment of the present invention;

[0017] Figure 3 is the first passive background original energy spectrum diagram provided by an embodiment of the present invention;

[0018] Figure 4 is the second passive background original energy spectrum diagram provided by an embodiment of the present invention;

[0019] Figure 5 is an energy spectrum diagram of the SPECT detector after passive calibration provided by an embodiment of the present invention;

[0020] Figure 6 is a schematic diagram of the SPECT detector calibration device provided by another embodiment of the present invention;

[0021] Figure 7 is a schematic diagram of the structure of an electronic device provided by another embodiment of the present invention. Detailed Embodiments

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, those of ordinary skill in the art can understand that in the embodiments of the present invention, many technical details are provided to help readers better understand the present invention. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the present invention can still be implemented. The following division of each embodiment is for convenience of description and should not constitute any limitation on the specific implementation of the present invention. Each embodiment can be combined and cross-referenced with each other on the premise of no contradiction.

[0023] To facilitate the understanding of the embodiments of the present invention, the relevant content of the SPECT detector calibration method will be introduced here first.

[0024] Single-Photon Emission Computed Tomography (SPECT) is a tomographic imaging technique for radioactive drugs (such as 99mTc) that emit only a single γ photon per decay. Discrete pixel-type SPECT detectors are usually composed of several methods such as array semiconductor radiation detectors, array scintillators, and optoelectronic devices. Each independent pixel detector in each array module can directly perform radiation detection.

[0025] Energy consistency refers to the consistency of the energy response of the SPECT detector to incident γ photons at different positions during SPECT or SPECT-CT acquisition. It is usually represented by the difference in the energy peak positions of the responses of each pixel to a uniform flood source radiation field. Poor energy consistency will cause distortion and distortion in the images acquired by SPECT.

[0026] The main factors that cause the deterioration of the energy consistency of the SPECT detector are: the output amplitude of each pixel detector changes; the environmental temperature changes, resulting in a change in the detector output amplitude; the aging of the semiconductor radiation detector or the poor coupling of the array scintillator + optoelectronic device will also cause a change in the energy response of the detector to the rays, etc.

[0027] In the related art, an energy correction table corresponding to each pixel is generated by using a radiation source (such as 99mTc, 57Co, etc.) to correct the energy of the detector, and the γ photons collected are energy-corrected through the correction table. However, this method requires the use of a radiation source, and a radiation source must be available for each calibration. At the same time, there are requirements for the activity and positioning of the radiation source, and professional technical operators, usually the technical personnel of the manufacturer, are required to operate. In the actual use process in hospitals, doctors or technicians often do not have the relevant professional capabilities to perform the calibration and need to invite relevant professionals to perform the calibration operation. Moreover, the radiation source poses a radiation hazard to the environment and operators during calibration.

[0028] To solve the above technical problems that continuous use of a radiation source is required to calibrate the SPECT detector, resulting in the need for professionals to perform the calibration and the radiation hazard caused by the use of the radiation source, the present invention proposes a method for calibrating an SPECT detector. The implementation details of the SPECT detector calibration method in this embodiment will be specifically described below. The following content is only for facilitating understanding of the implementation details and is not necessary for implementing this solution.

[0029] The SPECT detector calibration method in this embodiment can be applied to an electronic device with communication, computing, and data storage capabilities. The above SPECT detector has a corresponding preset passive energy calibration target peak channel address table, and the above preset passive energy calibration target peak channel address table is obtained from a preset source energy calibration table; its specific process can be as Figure 1 shown, including:

[0030] Step 101, perform passive calibration on the SPECT detector according to the preset passive energy calibration target peak channel address table to obtain a passive energy calibration table; the above passive energy calibration table is used to perform energy calibration on the γ photons acting on the SPECT detector when the SPECT detector images.

[0031] Specifically, the above SPECT detector has a corresponding preset passive energy calibration target peak channel address table, and the above preset passive energy calibration target peak channel address table is obtained from a preset source energy calibration table. The preset source energy calibration table is generated using a radiation source during installation and commissioning. In this embodiment, the radiation source only needs to be used once during installation and commissioning, and there is no need to use the radiation source during normal use of the device. Furthermore, during installation and commissioning, a passive energy calibration target peak channel address table is generated through the preset source energy calibration table.

[0032] In this embodiment, the radiation source is only used during device installation to generate a preset source energy calibration table; furthermore, a preset passive energy calibration target peak channel address table is generated through the preset source energy calibration table during device installation; then, passive energy calibration is performed through the preset passive energy calibration target peak channel address table to generate a passive energy calibration table, and passive energy calibration without using a radiation source can be completed. During normal use of the device, passive energy calibration can be completed only by performing passive energy calibration through the passive energy calibration target peak channel address table to generate a passive energy calibration table. This process does not require the use of a radiation source. On the one hand, calibration does not require professionals, and users such as doctors or technicians can also perform the calibration, saving human resources. On the other hand, it can avoid the radiation hazard caused by the radiation source during calibration.

[0033] In some embodiments, the above preset source energy calibration table is obtained according to the following steps:

[0034] Step a1, remove the collimator of the above SPECT detector.

[0035] Specifically, the collimator of the SPECT detector is an important component, and its main function is to limit the range and direction of γ-rays entering the crystal. This can ensure that the γ-rays received by the detector are from a specific direction and are collimated, thereby improving the quality and accuracy of imaging. During the calibration process, on the one hand, it may be necessary to directly calibrate the crystal or other sensitive components of the detector to ensure the accuracy and consistency of its response. Removing the collimator allows the calibration source (such as a radioactive isotope source) to directly irradiate the crystal, enabling more precise calibration. On the other hand, the collimator itself may cause certain interference to the calibration process. For example, its material may absorb or scatter the radiation of the calibration source, thereby affecting the accuracy of the calibration result. Removing the collimator can reduce this interference and make the calibration process more accurate and reliable. Step a2, collect the original energy spectrum corresponding to each pixel of the radioactive standard source. Therefore, when calibrating the SPECT detector, it is necessary to remove the collimator of the above SPECT detector.

[0036] Step a2, collect the original energy spectrum corresponding to each pixel of the radioactive standard source.

[0037] Specifically, the radioactive standard source is the radiation source used for calibration, and as an example, it can be: 99m Tc radiation source. The collected original energy spectrum refers to the energy distribution information generated after the SPECT detector receives the γ-rays emitted by the radioactive standard source through a series of physical processes (such as the photoelectric effect, Compton scattering, etc.). This energy distribution information is usually represented in the form of a pulse amplitude distribution, that is, the curve of the counting rate versus the particle energy obtained after the pulse amplitude is energy-scaled, which is the original energy spectrum.

[0038] Step a3, generate a preset energy correction table with source according to the original energy spectrum corresponding to each pixel of the radioactive standard source.

[0039] Specifically, as an example: 99m The preset energy correction parameter A corresponding to the pixel coordinates (i, j) in the preset energy correction table with source corresponding to the Tc radiation source i，j meets the following conditions:

[0040] A i，j = E i，j / 141

[0041] where 141 is 99m the energy peak correction value of the Tc radiation source; E i，jis the original peak channel address corresponding to the pixel coordinates (i, j); i = 1, 2, 3 ···; j = 1, 2, 3 ···.

[0042] It should be noted that the distance between the above radioactive standard source and the center of the SPECT detector probe is greater than 5 times the field of view distance of the SPECT detector probe.

[0043] In some embodiments, the above preset passive energy correction target peak channel address table is obtained according to the following steps:

[0044] Step b1, according to the above preset source energy correction table, collect the first passive background original energy spectrum corresponding to each pixel within a preset time period.

[0045] Specifically, after collection, record the first passive background original energy spectrum corresponding to each pixel. Among them, the time length of the preset time period is equal to or greater than 8. When using the preset source energy correction table, the detector can accurately correct the collected passive background original energy spectrum according to the preset correction parameters. As an example:

[0046] Step b2, perform smoothing filtering on the first passive background original energy spectrum corresponding to each pixel to obtain the peak channel address of each first passive background original energy spectrum, so as to generate a preset passive energy correction target peak channel address table.

[0047] Specifically, as shown by the abscissa position of the dotted line in Figure 3 , obtain the peak channel address of each first passive background original energy spectrum and record the peak channel address of each first passive background original energy spectrum. The peak channel address usually refers to the channel address (or energy channel) where the energy pulse count reaches the maximum value in the energy spectrum distribution. The information of the peak channel address can be used to evaluate the performance and stability of the detector, as well as perform tasks such as energy spectrum correction and image reconstruction. As an example: taking the 99m Tc radioactive source as an example, the first passive background original energy spectrum is as shown in Figure 3 , and the corresponding peak channel address is as shown by the abscissa position of the dotted line in Figure 3 .

[0048] In some embodiments, the above passive correction of the SPECT detector according to the preset passive energy correction target peak channel address table to obtain a passive energy correction table includes:

[0049] Step c1, collect the second passive background original energy spectrum corresponding to each pixel within a preset time period.

[0050] Specifically, when collecting the second passive background raw energy spectrum corresponding to each pixel within a preset time period, the preset energy correction table with a radiation source is not used. At this time, due to the absence of a radiation source, the energy distribution information generated by the background radiation or environmental noise collected by the SPECT detector. The second passive background raw energy spectrum is the energy pulse distribution generated by factors such as cosmic rays, environmental radioactive substances, and detector internal electronics noise when the detector is in a normal working state. Here, the time length of the preset time period is equal to or greater than 8 hours.

[0051] Step c2, perform a smoothing filtering process on the second passive background raw energy spectrum corresponding to each pixel to obtain the peak channel address of each second passive background raw energy spectrum.

[0052] Specifically, as an example: taking 99m the 99mTc radiation source as an example, the second passive background raw energy spectrum is as shown in Figure 4 the figure, and the corresponding peak channel address is as shown at the horizontal coordinate position indicated by the dashed line in Figure 4 the figure.

[0053] Step c3, generate a passive energy correction table according to the above preset passive energy correction target peak channel address table and the peak channel address of each second passive background raw energy spectrum.

[0054] Specifically, the passive energy correction parameter C i，j corresponding to the pixel coordinates (i, j) satisfies the following conditions:

[0055] C i，j = e i，j / B i，j

[0056] where e i，j is the peak channel address parameter of the first passive background raw energy spectrum corresponding to the pixel coordinates (i, j); B i，j is the peak channel address parameter of the second passive background raw energy spectrum corresponding to the pixel coordinates (i, j).

[0057] In this embodiment, according to the gap between the peak channel addresses of the passive background raw energy spectra obtained when using the preset energy correction table with a radiation source and when not using the preset energy correction table with a radiation source, the correction parameter is determined. There is no need to continuously use a radiation source for correction. On the one hand, there is no need for professional personnel to perform the correction, and users such as doctors or technicians can also perform the correction, saving human resources. On the other hand, it can avoid the radiation hazards caused by the radiation source during correction.

[0058] The following uses a specific embodiment to illustrate the SPECT detector correction method provided by the present invention: After the SPECT detector adopts passive correction and is equipped with a passive correction table for collecting the 99mTc radiation source, the effects before and after correction are compared as shown in Figure 2and Figure 5 As shown, it can be found that the energy peak channel address position after calibration is 141, achieving the calibration effect. In the above Figures 2 - 5 energy spectrum diagram, the abscissa is energy, with the unit of keV, and the ordinate is the cumulative count.

[0059] Another embodiment of the present invention relates to a SPECT detector calibration device. The above SPECT detector has a corresponding preset passive energy calibration target peak channel address table, and the above preset passive energy calibration target peak channel address table is obtained according to a preset source energy calibration table; the implementation details of the PECT detector calibration device in this embodiment will be specifically described below. The following content is only the implementation details provided for convenience of understanding and is not necessary for implementing this solution. The schematic diagram of the SPECT detector calibration device in this embodiment can be as Figure 6 shown, including a calibration module 601. Specifically,

[0060] The calibration module 601 performs passive calibration on the SPECT detector according to the above preset passive energy calibration target peak channel address table to obtain a passive energy calibration table; the above passive energy calibration table is used to perform energy calibration on the γ photons acting on the SPECT detector when the SPECT detector images.

[0061] It is worth mentioning that each module involved in this embodiment is a logic module. In practical applications, a logic unit can be a physical unit, a part of a physical unit, or a combination of multiple physical units. In addition, in order to highlight the innovative part of the present invention, units that are not closely related to solving the technical problems proposed by the present invention are not introduced in this embodiment, but this does not mean that there are no other units in this embodiment.

[0062] Another embodiment of the present invention relates to an electronic device, as Figure 7 shown, including: at least one processor 701; and a memory 702 communicatively connected to the at least one processor 701; wherein, the memory 702 stores instructions executable by the at least one processor 701, and the instructions are executed by the at least one processor 701 to enable the at least one processor 701 to execute the SPECT detector calibration method in the above embodiments.

[0063] Among them, the memory and the processor are connected in a bus manner. The bus can include any number of interconnected buses and bridges, which connect various circuits of one or more processors and the memory together. The bus can also connect various other circuits such as peripheral devices, voltage regulators, and power management circuits, etc., which are well known in the art, so they will not be further described herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be a component or multiple components, such as multiple receivers and transmitters, providing units for communicating with various other devices on the transmission medium. The data processed by the processor is transmitted on the wireless medium through the antenna. Further, the antenna also receives data and transmits the data to the processor.

[0064] The processor is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interface, voltage regulation, power management, and other control functions. The memory can be used to store the data used by the processor when executing operations.

[0065] Another embodiment of the present invention relates to a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the above method embodiment is implemented.

[0066] That is, those skilled in the art can understand that all or part of the steps in implementing the above method embodiments can be completed by instructing relevant hardware through a program. This program is stored in a storage medium, including several instructions to enable a device (which can be a single-chip microcomputer, a chip, etc.) or a processor to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: USB flash drives, mobile hard disks, read-only memories (ROM for short), random access memories (RAM for short), magnetic disks, or optical discs, etc., all kinds of media that can store program codes.

[0067] Those of ordinary skill in the art can understand that the above embodiments are specific embodiments for implementing the present invention, and in practical applications, various changes can be made in form and details without departing from the spirit and scope of the present invention.

Claims

1. A SPECT detector calibration method, characterized in that: The SPECT detector has a corresponding preset passive energy correction target peak channel address table, and the preset passive energy correction target peak channel address table is obtained according to a preset source energy correction table; the method comprises: The SPECT detector is passively corrected according to the preset passive energy correction target peak channel address table to obtain a passive energy correction table; the passive energy correction table is used to perform energy correction on the gamma photons acting on the SPECT detector when the SPECT detector is imaging.

2. The SPECT detector calibration method according to claim 1, characterized in that: The preset band source energy correction table is obtained according to the following steps: removing a collimator of the SPECT detector; Collect the original energy spectrum corresponding to each pixel of the radioactive standard source; A preset band source energy correction table is generated based on the original energy spectrum corresponding to each pixel of the radioactive standard source.

3. The SPECT detector calibration method according to claim 2, characterized in that: The distance between the radioactive standard source and the center of the probe of the SPECT detector is greater than 5 times the distance of the field of view of the probe of the SPECT detector.

4. The SPECT detector calibration method according to claim 1, characterized in that: The preset passive energy correction target peak channel address table is obtained according to the following steps: According to the preset source energy correction table, collecting the first passive background original energy spectrum corresponding to each pixel within a preset time period; The first passive background original energy spectrum corresponding to each pixel is smoothed and filtered to obtain the peak channel address of each first passive background original energy spectrum, so as to generate a preset passive energy correction target peak channel address table.

5. The SPECT detector calibration method according to claim 1, characterized in that: The step of performing passive correction on the SPECT detector according to the preset passive energy correction target peak channel address table to obtain a passive energy correction table includes: Collecting the second passive background original energy spectrum corresponding to each pixel within a preset time period; Performing smoothing filtering on the second passive background original energy spectrum corresponding to each pixel to obtain the peak address of each second passive background original energy spectrum; A passive energy correction table is generated according to the preset passive energy correction target peak channel address table and the peak channel address of each second passive background original energy spectrum.

6. The SPECT detector calibration method according to claim 4 or 5, characterized in that: The duration of the preset time period is equal to or greater than 8 hours.

7. The SPECT detector calibration method according to claim 5, characterized in that: When collecting the second passive background original energy spectrum corresponding to each pixel within the preset time period, the preset band source energy correction table is not used.

8. A SPECT detector calibration device, characterized in that: The SPECT detector has a corresponding preset passive energy correction target peak channel address table, and the preset passive energy correction target peak channel address table is obtained according to a preset source energy correction table; the device comprises: The correction module performs passive correction on the SPECT detector according to the preset passive energy correction target peak channel address table to obtain a passive energy correction table; the passive energy correction table is used to perform energy correction on the gamma photons acting on the SPECT detector when the SPECT detector is imaging.

9. An electronic device, characterized in that: include: at least one processor; as well as, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can perform the SPECT detector calibration method according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the SPECT detector calibration method according to any one of claims 1 to 7 is implemented.

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