Gamma camera imaging method and apparatus

Abstract

The present disclosure provides a gamma camera imaging method and apparatus. The method includes selecting one or more energy ranges for each of one or more radioactive substances from an energy spectrum of the one or more radioactive substances captured by a gamma camera as one or more monitoring energy regions for the radioactive substance; performing image reconstruction for the monitoring energy regions for each of the one or more radioactive substances, respectively; normalizing each image obtained by the image reconstruction; and superimposing the normalized images to form a composite image.

Description

Technical Field

[0001] This invention relates to the technical field of gamma cameras, and more particularly to gamma camera imaging methods and apparatus. Background Technology

[0002] Gamma cameras are used in the fields of nuclear safety and nuclear detection. Their main function is to perform dynamic and static imaging of the radiation field in areas contaminated with radioactive materials, and to fuse the images with optical images to obtain information on the distribution of radioactive materials.

[0003] Existing gamma cameras typically employ linear data processing methods, meaning they do not differentiate between received signals and perform projection image restoration and original image reconstruction on signals from all effective energy ranges together. Because of quantization loss and approximation during data processing, the reconstructed image often contains statistical fluctuations and shadows in the background of bright spots. Subsequently, image regions are filtered using brightness or saliency thresholds, selecting only the more prominent imaging areas for fusion with the optical image. Summary of the Invention

[0004] According to one aspect of this application, a gamma camera imaging method is provided, the method comprising: selecting one or more energy ranges of each radioactive substance from the energy spectrum of one or more radioactive substances captured by the gamma camera as one or more monitoring energy regions of the radioactive substance; reconstructing images for each monitoring energy region of the one or more radioactive substances; normalizing the images obtained by the image reconstruction; and superimposing the normalized images to form a composite image.

[0005] In some embodiments, the selection includes: performing a peak search through the energy spectrum, comparing the peak search results with the energies of each branch of a radioactive material recorded in a predetermined nuclide library to identify the one or more radioactive materials; for each of the one or more radioactive materials, identifying the branches with higher or lower energies among the branches of that radioactive material as one or more branches to be monitored; and for each of the one or more branches of each radioactive material, identifying the energy range centered on the center energy of that branch and with the full width at half maximum (FWHM) of the corresponding spectral peak of that branch as one or more monitoring energy regions of that radioactive material.

[0006] In some embodiments, the gamma camera imaging method further includes: determining whether there is a closed region in each of the images obtained by image reconstruction; and if the contrast ratio between the closed region and the background region outside the closed region is less than a predetermined threshold when a closed region exists in the image, adaptively adjusting the energy range of the monitoring energy region corresponding to the image.

[0007] In some embodiments, the adaptive adjustment includes: gradually increasing or decreasing the monitoring energy region to be adjusted in predetermined energy steps until the contrast between the closed region and the background region outside the closed region reaches the predetermined threshold.

[0008] In some embodiments, the gamma camera imaging method further includes discarding data of the monitoring energy region corresponding to the image when there is no closed region in the image.

[0009] In some embodiments, the gamma camera imaging method further includes: discarding data of the monitoring energy region corresponding to the image after a predetermined time, in the case that there is no closed region in the image.

[0010] According to another aspect of this application, a gamma camera imaging apparatus is provided, comprising: a selection module for selecting one or more energy ranges of each radioactive substance from the energy spectrum of one or more radioactive substances captured by the gamma camera as one or more monitoring energy regions of the radioactive substance; an image reconstruction module for reconstructing images for each monitoring energy region of the one or more radioactive substances; a normalization module for normalizing the images obtained by the image reconstruction; and a superposition module for superimposing the normalized images to form a composite image.

[0011] In some embodiments, the selection module includes: a peak-finding module, which performs a traversal peak-finding operation from the energy spectrum and compares the peak-finding results with the energies of each branch of a radioactive material recorded in a predetermined nuclide library to identify the one or more radioactive materials; a branch-determination module, which, for each of the one or more radioactive materials, determines the branches with higher or lower energies among the branches of that radioactive material as one or more branches to be monitored; and an energy region determination module, which, for each of the one or more branches of each radioactive material, determines the energy range centered on the center energy of that branch and with the full width at half maximum (FWHM) of the corresponding spectral peak of that branch as one or more monitoring energy regions of that radioactive material.

[0012] In some embodiments, the image reconstruction module further includes: a closed region determination module, for each image obtained by image reconstruction, determining whether there is a closed region in each of the images; and an energy range adjustment module, in the case that a closed region exists in the image, if the contrast ratio between the closed region and the background region outside the closed region is less than a predetermined threshold, adaptively adjusting the energy range of the monitoring energy range corresponding to the image.

[0013] In some embodiments, the energy region adjustment module is configured to: gradually attempt to expand or reduce the monitoring energy region to be adjusted in units of a predetermined energy step, until the contrast between the closed region and the background region outside the closed region reaches the predetermined threshold.

[0014] In some embodiments, the image reconstruction module further includes a discard module configured to discard data of the monitoring energy region corresponding to the image when no closed region exists in the image. In some embodiments, the discard module is configured to discard data of the monitoring energy region corresponding to the image after a predetermined time when no closed region exists in the image.

[0015] According to another aspect of this application, a gamma camera imaging apparatus is provided, comprising: a memory storing instructions; and a processor configured to execute the instructions stored in the memory to perform the gamma camera imaging method described above.

[0016] According to another aspect of this application, a computer-readable storage medium is provided, storing instructions that, when executed by a processor, cause the processor to perform the above-described gamma camera imaging method.

[0017] According to another aspect of this application, a gamma camera is provided, including any of the above-described gamma camera imaging devices.

[0018] The gamma camera imaging method and apparatus according to embodiments of this application, by analyzing each monitoring energy region of each radioactive material individually, can take all radioactive materials into account and reduce background noise, thereby improving the signal-to-noise ratio. Furthermore, the gamma camera imaging method and apparatus according to embodiments of this application can also refresh only the projected image of moving radioactive materials in dynamic measurement mode, ensuring that the imaging of moving and stationary materials does not interfere with each other. Attached Figure Description

[0019] The features and advantages of the invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the invention in any way. In the drawings:

[0020] Figure 1 A diagram showing the energy spectra captured by a gamma camera from three radioactive sources (Am241, Co57, Ba133);

[0021] Figure 2 This demonstrates how a gamma camera uses conventional methods to... Figure 1 Example images obtained by reconstructing the energy spectra of three radioactive sources (Am241, Co57, Ba133).

[0022] Figure 3The figure illustrates a flowchart of a gamma camera imaging method according to an embodiment of this application;

[0023] Figure 4 A diagram showing the energy spectra captured by a gamma camera from three radioactive sources (Am241, Co57, Ba133);

[0024] Figure 5 The figure illustrates a gamma camera using the method described in the embodiments of this application. Figure 4 An example composite image obtained by reconstructing the energy spectra of three radioactive sources (Am241, Co57, Ba133);

[0025] Figure 6 The figure illustrates the energy spectrum captured by a gamma camera from high-energy radioactive material (e.g., Co60);

[0026] Figure 7 This diagram illustrates a comparison between images obtained by reconstructing images of two radioactive sources (Am241, Co57) using a gamma camera with conventional methods and images obtained by reconstructing images of the same radioactive sources using the method described in this application.

[0027] Figure 8 The figure illustrates a block diagram of a gamma camera imaging apparatus according to an embodiment of this application; and

[0028] Figure 9 The figure shows an example block diagram of a computing device that can be used to implement a gamma camera imaging apparatus according to embodiments of this application. Detailed Implementation

[0029] The results of gamma camera monitoring are presented as images. The distribution and type of radioactive materials are determined by observing the images on the screen with the human eye. Therefore, whether radioactive materials can be imaged is crucial to the monitoring results of gamma cameras. The basic condition for imaging is that, from a statistical perspective, the number of gamma events emitted by the radiation source exceeds a certain proportion of the background gamma events in the environment. That is, the signal-to-noise ratio must reach a certain threshold before relatively ideal analytical results can be obtained through statistical and image processing methods.

[0030] Achieving a specified signal-to-noise ratio in practical applications is challenging. This is because limitations in detector size and materials result in low detection efficiency for high-energy particles. Furthermore, a significant amount of ambient noise exists in the environment for low-energy particles. Consequently, traditional gamma cameras typically have limited detection ranges and require relatively long measurement times.

[0031] Figure 1 The illustration shows the energy spectra captured by the gamma camera from three radioactive sources (Am241, Co57, Ba133). Figure 1 Including Figure 1 (a) and Figure 1 (b), where the horizontal axis represents energy in Tao values ​​and the vertical axis represents count values. Figure 1 (a) The energy spectrum region produced by Am241 is marked with a solid line box, the energy spectrum region produced by Co57 is marked with a dotted-dash line box, and the energy spectrum region produced by Ba133 is marked with a dashed line box. Figure 1 In (b), the light gray area provides valid information, while the dark gray area provides noise information (in this example, only the full-energy peak is used, and Compton scattering plateau data is not used as valid information for imaging). For gamma camera data processing, a certain ratio between the area of ​​the light gray area and the area of ​​the dark gray area is required to ensure good imaging by the gamma camera.

[0032] If imaging is possible, and the intensity of various radioactive substances varies significantly, the brightness of the bright spots formed by each radioactive point source in the reconstructed image will also differ greatly. The bright spots of weak sources are easily submerged in the statistical fluctuation background formed by strong sources. Since their brightness values ​​are unlikely to exceed the screening threshold, they will not be selected for fusion with the optical image. Or even if they are selected for fusion with the optical image, their brightness will be very weak and difficult to observe with the naked eye.

[0033] Figure 2 This demonstrates how a gamma camera uses conventional methods to... Figure 1 Example images were obtained by reconstructing the energy spectra of three radioactive sources (Am241, Co57, and Ba133). The horizontal and vertical axes in this image represent the pixel scale of the gamma-ray camera image. In this image, only the bright spots represented by the two peaks of Am241 in the energy spectrum are observable; Co57 and Ba133 are not visible. Therefore, conventional methods fail to fully represent information from all radioactive sources.

[0034] According to embodiments of this application, a gamma camera imaging method and apparatus are provided, which can make full use of the effective information of each radioactive source and optimize the distribution of radioactive materials in the field of view.

[0035] Figure 3 The figure illustrates a flowchart of a gamma camera imaging method according to an embodiment of this application. Figure 3 As shown, the gamma camera imaging method 100 according to an embodiment of this application includes: S101-S104.

[0036] In step S101, one or more energy ranges of each radioactive material are selected from the energy spectrum of one or more radioactive materials captured by the gamma camera as one or more monitoring energy regions of that radioactive material.

[0037] For step S01, in some embodiments, the selection of the monitoring energy region may include: traversing the energy spectrum to find peaks, comparing the peak finding results with the energies of each branch of the radioactive material recorded in a predetermined nuclide library to determine the one or more radioactive materials; for each of the one or more radioactive materials, determining the branches with higher or lower energies among the branches of that radioactive material as one or more branches to be monitored; and for each of the one or more branches of each radioactive material, determining the energy range centered on the center energy of that branch and with the full width at half maximum (FWHM) of the corresponding spectral peak of that branch as the width of one or more monitoring energy regions of that radioactive material.

[0038] It should be understood that a single monitoring energy region or multiple monitoring energy regions can be selected for a single radioactive material, and the selected monitoring energy regions may overlap for different radioactive materials. Furthermore, the determination of the branch for each radioactive material is primarily based on two criteria: branching ratio and energy. Because gamma camera detectors have very low detection efficiency for high-energy gamma particles, lower-energy branches are preferred. Also, because a higher branching ratio results in more gamma particles produced by the same amount of radioactive material, branches with higher branching ratios are preferred. It should be understood that the terms "lower" and "higher" used here are relative to the different branches of the radioactive material.

[0039] In step S102, image reconstruction is performed for the monitoring energy region of each of the one or more radioactive substances.

[0040] For step S102, image reconstruction can be performed using either commonly used correlation decoding methods or statistical decoding methods as needed.

[0041] In some embodiments, the gamma camera imaging method according to this application further includes: determining whether there is a closed region in each image obtained through image reconstruction; if a closed region exists in the image, and if the contrast ratio between the closed region and the background region outside the closed region is less than a predetermined threshold, then adaptively adjusting the energy range of the monitoring energy region corresponding to the image. In some embodiments, adaptive adjustment may include: gradually expanding or decreasing the monitoring energy region to be adjusted in predetermined energy step sizes until the contrast ratio between the closed region and the background region outside the closed region reaches the predetermined threshold. The adaptively adjusted energy range is determined by the detector resolution and the distance between adjacent peaks. Generally, if the energy calibration of the gamma camera is relatively accurate, the degree of adaptive adjustment is not large; for example, 2 to 5 half-width ranges can generally be selected.

[0042] The gamma camera can operate in both static and dynamic measurement modes. In static measurement mode, the method according to this application may further include discarding data of the monitoring energy region corresponding to the image if no closed region exists in the image. Alternatively, in dynamic measurement mode, the method according to this application may further include discarding data of the monitoring energy region corresponding to the image after a predetermined time if no closed region exists in the image. Since the dynamic movement of radioactive materials in dynamic measurement mode may cause closed regions to appear in the reconstructed image, data is discarded only after a predetermined observation period if no closed region is found. By discarding monitoring energy region data that cannot be imaged, not only can the computational load be reduced, but the impact of background noise can also be reduced.

[0043] In step S103, the images obtained through image reconstruction are normalized. In step S103, the pixel values ​​are normalized from the maximum and minimum value range to the range of zero to one. Because each image is normalized to the same maximum value, this is equivalent to enhancing the weak source image.

[0044] In step S104, the normalized images are superimposed to form a composite image. For step S104, different color channels can be used for image superposition to clearly show the distribution of each radioactive material.

[0045] According to the gamma camera imaging method of the embodiments of this application, data from each monitoring energy zone is analyzed separately. This eliminates other information outside that energy zone, leaving only background events within that zone as noise. This noise is significantly reduced compared to the overall background, thus effectively improving the signal-to-noise ratio. Furthermore, another advantage of analyzing data from each monitoring energy zone separately according to the gamma camera imaging method of the embodiments of this application is that, in dynamic mode, when the movement of a radioactive material is detected in real time, only the projected image of the selected monitoring energy zone of that radioactive material needs to be cleared for refreshing, without clearing other monitoring energy zones. Therefore, when using the same monitoring energy zone, the imaging of moving and stationary materials does not affect each other.

[0046] Figure 4 This diagram illustrates the energy spectra captured by a gamma camera from three radioactive sources (Am241, Co57, Ba133). Figure 4 In the diagram, the horizontal axis represents energy in channels, and the vertical axis represents count values. The light gray area provides valid information, while the dark gray area provides noise information. For example... Figure 4As shown, the gamma camera imaging method according to an embodiment of this application determines four monitoring energy regions from the total energy spectrum, including two branches of Am241 (shown as spectral peaks in the figure, referred to as the first and second spectral peaks respectively), one branch of Co57 (referred to as the third spectral peak), and one branch of Ba133 (referred to as the fourth spectral peak). These are the optimal signal-to-noise ratio regions. Imaging is performed for each of these four monitoring energy regions. The characteristic peak at 355 keV of Ba133 cannot be imaged because its optimal signal-to-noise ratio region does not meet the threshold requirement.

[0047] The images obtained from image reconstruction for these four monitoring energy zones are normalized, and the normalized images are then superimposed to form a composite image. Figure 5 The figure illustrates a gamma camera using the method described in the embodiments of this application. Figure 4 An example composite image obtained by reconstructing the energy spectra of three radioactive sources (Am241, Co57, Ba133). Figure 5 In the image, the first and second spectral peaks are reconstructed to obtain the image of Am241, the third spectral peak is reconstructed to obtain the image of Ba133, and the fourth spectral peak is reconstructed to obtain the image of Co57. The imaging positions are indicated by arrows in the images.

[0048] Compared with images obtained using conventional methods (such as...) Figure 2 Compared to the image obtained by the gamma camera imaging method according to the embodiments of this application (as shown), the image obtained by the gamma camera imaging method according to the embodiments of this application (as shown) Figure 5 The diagram shows more information about the radioactive material. Because gamma cameras have low detection efficiency and energy resolution, the probability of weak peaks overlapping is relatively high, and conventional peak-finding methods based on curve shape cannot find peaks well. Therefore, this method uses a traversal method similar to nuclide library peak finding. Since gamma cameras can only detect a limited number of radioactive materials, even if traversal calculations are performed for all detectable radioactive materials, the computational load and real-time processing speed are within acceptable limits. In some special cases, such as high-energy radioactive materials (e.g., Co60), because the signal-to-noise ratio is improved, only a few dozen gamma events are needed to form a good image, which can actually reduce measurement time. For example, Figure 6 The optimal imaging energy range of Co60 is in the 300-450 channel range (shown by the box in the figure). Although no peak shape can be observed in the energy spectrum, the method according to the embodiments of this application can obtain a very obvious reconstructed image.

[0049] The method in this application primarily displays the types and distribution of radioactive materials within the field of view of a gamma camera. For applications using gamma cameras, the presence and location information of radioactive materials are more important than their relative strength. If it is necessary to check the strength information of radioactive materials, a separate display mode can be used.

[0050] As another example, Figure 7 This diagram illustrates a comparison between images obtained by reconstructing images of two radioactive sources (Am241, Co57) using a gamma camera with conventional methods and images obtained by reconstructing images of the same radioactive sources using the method described in this application. Figure 7 Including the left side Figure 7 (a) and the right side Figure 7 (b), where Figure 7 (a) is a gamma image obtained using conventional methods, while Figure 7 (b) is a gamma image obtained using the method of this application embodiment. Within the radiation field of view measured by the gamma camera, there are two radioactive point sources: Am241 and Co57. In the image on the left, only the bright spot of Am241, located slightly to the left of center, is visible because the activity of the Am241 source is high, and the overall background is very bright, thus obscuring the bright spot of Co57. In the image on the right, the imaging of both point sources (Am241, Co57) is clearly visible (Am241 on the left, Co57 on the right). It should be noted that the method according to this application embodiment can synthesize each reconstructed image using different color channels to make the resulting gamma image a color image; for example, Am241 can be represented in cyan, and Co57 can be displayed in red. The color channels can differ from the example and can be set according to requirements.

[0051] The following describes a gamma camera imaging apparatus according to embodiments of this application. Figure 8 The figure shows a block diagram of a gamma camera imaging apparatus according to an embodiment of this application. Figure 8 As shown, the gamma camera imaging apparatus 800 according to an embodiment of this application includes a selection module 801, an image reconstruction module 802, a normalization module 803, and a superposition module 804. Specifically, the selection module 801 selects one or more energy ranges of each radioactive substance from the energy spectrum of one or more radioactive substances captured by the gamma camera as one or more monitoring energy regions of that radioactive substance; the image reconstruction module 802 performs image reconstruction for each monitoring energy region of the one or more radioactive substances; the normalization module 803 normalizes each image obtained through the image reconstruction; and the superposition module superimposes the normalized images to form a composite image.

[0052] In some embodiments, the selection module 801 includes: a peak-finding module 8011, which performs a traversal peak-finding operation from the energy spectrum and compares the peak-finding results with the energies of each branch of a radioactive material recorded in a predetermined nuclide library to identify the one or more radioactive materials; a branch-determination module 8012, which, for each of the one or more radioactive materials, determines the branches with higher or lower energies among the branches of that radioactive material as one or more branches to be monitored; and an energy region determination module 8013, which, for each of the one or more branches of each radioactive material, determines the energy range centered on the center energy of that branch and with the full width at half maximum (FWHM) of the corresponding spectral peak of that branch as one or more monitoring energy regions of that radioactive material.

[0053] In some embodiments, the image reconstruction module 802 includes: a closed region determination module 8021, which determines whether there is a closed region in each image obtained by the image reconstruction; and an energy range adjustment module 8022, which, if a closed region exists in an image, adaptively adjusts the energy range of the monitoring energy range corresponding to the image if the contrast ratio between the closed region and the background region outside the closed region is less than a predetermined threshold.

[0054] In some embodiments, the energy zone adjustment module 8022 is configured to: gradually attempt to expand or reduce the monitoring energy zone to be adjusted in units of a predetermined energy step, until the contrast between the closed region and the background region outside the closed region reaches the predetermined threshold.

[0055] In some embodiments, the image reconstruction module 802 further includes a discard module 8023, which is configured to discard data of the monitoring energy region corresponding to the image when there is no closed region in the image. In some embodiments, the discard module 8023 is configured to discard data of the monitoring energy region corresponding to the image after a predetermined time when there is no closed region in the image.

[0056] The gamma camera imaging method and apparatus according to the embodiments of this application can be used in a gamma camera to obtain enhanced gamma images, which can then be fused with optical images to identify radioactive materials and their distribution information. By analyzing each monitoring energy region of each radioactive material individually, the gamma camera imaging method and apparatus according to the embodiments of this application can take all radioactive materials into account and reduce background noise, thereby improving the signal-to-noise ratio. Furthermore, the gamma camera imaging method and apparatus according to the embodiments of this application can also refresh only the projected image of moving radioactive materials in dynamic measurement mode, ensuring that the imaging of moving and stationary materials does not interfere with each other.

[0057] In some embodiments, this application also provides a gamma camera imaging apparatus, comprising: a memory storing instructions; and a processor configured to execute the instructions stored in the memory to perform the gamma camera imaging method according to the above description.

[0058] In some embodiments, this application also provides a gamma camera, including the gamma camera imaging device described above.

[0059] Figure 9 The figure illustrates an example block diagram of a computing device that can be used to implement a gamma camera imaging apparatus according to embodiments of the present application. As shown, the computing device 900 may include one or more processors or processor cores 901 and memory 902. For the purposes of this application (including the claims), the terms "processor" and "processor core" may be considered synonymous unless the context explicitly requires otherwise. Processor 901 may include any type of processor, such as a central processing unit, a microprocessor, etc. Processor 901 may be implemented as an integrated circuit with multiple cores, such as a multi-core microprocessor. In embodiments, memory 902 may be system memory. In some embodiments, memory 902 may be integrated with processor 901. The computing device 900 may include a mass storage device 903 (e.g., a magnetic disk, a hard disk drive, volatile memory (e.g., dynamic random-access memory (DRAM), compact discread-only memory (CD-ROM), digital versatile disk (DVD), etc.). Generally, memory 902 and / or mass storage device 903 can be any type of temporary and / or persistent storage, including but not limited to volatile and non-volatile memory, optical, magnetic, and / or solid-state mass storage, etc. Volatile memory may include, but is not limited to, static and / or dynamic random-access memory. Non-volatile memory may include, but is not limited to, electrically erasable programmable read-only memory, phase-change memory, resistive memory, etc.

[0060] The computing device 900 may also include input / output (I / O) devices 904 (e.g., a display (e.g., a touchscreen display), a keyboard, cursor control, a remote control, a game controller, an image capture device, etc.) and a communication interface 905 (e.g., a network interface card, a modem, an infrared receiver, a radio receiver (e.g., Bluetooth), etc.). The communication interface 905 can communicate with other devices in a wired or wireless manner to exchange data. For example, through this communication interface 905, gamma images can be transmitted for fusion with optical images.

[0061] The elements of the aforementioned computing device 900 can be coupled to each other via a system bus 906, which represents one or more buses. In the case of multiple buses, they can be bridged by one or more bus bridges (not shown). Each of these elements can perform its conventional functions known in the art. Specifically, a memory 902 and a mass storage device 903 can be used to store working copies and permanent copies of programming instructions for the operation of the gamma camera imaging device. The various elements can be implemented using assembly instructions supported by one or more processors 901 or high-level languages ​​that can be compiled into such instructions. Permanent copies of the programming instructions can be placed in the mass storage device 903 at the factory, or distributed in the field via, for example, a distribution medium (not shown) (such as a CD) or via a communication interface 905 (from a distribution server (not shown)). Therefore, in some embodiments, this application provides a computer-readable storage medium storing instructions that, when executed by a processor, cause the processor to perform the aforementioned gamma camera imaging method.

[0062] The number, capabilities, and / or capacity of the components may vary depending on whether the computing device 900 is used as a stationary computing device or a mobile computing device. In various implementations, the computing device 900 may include one or more components of a laptop, netbook, notebook, ultrabook, smartphone, tablet device, personal digital assistant (PDA), ultra-mobile PC, mobile phone, or digital camera. In other implementations, the computing device 900 may be any other electronic device that processes data.

[0063] The foregoing detailed description of embodiments of the present invention covers many specific details in order to provide a comprehensive understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without some of these specific details. The foregoing description of the embodiments is merely intended to provide a clearer understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific configurations and method steps set forth below, but covers any modifications, substitutions, and improvements to the related elements, components, and method steps without departing from the teachings of the invention.

[0064] It should be noted that in the claims, the words "comprising" or "including" do not exclude the presence of elements or components not listed in the claims. Similarly, the article "a" or "an" preceding an element or component does not exclude the presence of a plurality of such elements or components.

[0065] Furthermore, it should be noted that the language used in this specification has been chosen primarily for readability and instructional purposes, rather than for interpreting or limiting the subject matter of the invention. Therefore, many modifications and alterations will be apparent to those skilled in the art without departing from the scope and spirit of the appended claims. Regarding the scope of the invention, the descriptions in this specification are illustrative and not restrictive, and the scope of the invention is defined by the appended claims.

Claims

1. A gamma camera imaging method, comprising: Select one or more energy ranges for each radioactive substance from the energy spectrum of one or more radioactive substances captured by the gamma camera as one or more monitoring energy regions for that radioactive substance. Image reconstruction is performed separately for the monitoring energy region of each of the one or more radioactive substances; Normalize each image obtained by reconstructing the image; as well as The normalized images are superimposed to form a composite image. The selection includes: A peak search is performed on the energy spectrum, and the peak search results are compared with the energies of each branch of radioactive material recorded in the predetermined nuclide library to determine one or more radioactive materials. For each of the one or more radioactive substances, the branches with higher or lower energy among the branches of that radioactive substance are identified as one or more branches of that radioactive substance to be monitored; and For each of the one or more branches of a radioactive material, the energy range centered on the center energy of that branch and with the full width at half maximum (FWHM) of the corresponding spectral peak of that branch as its width is determined as one or more monitoring energy regions of that radioactive material.

2. The gamma camera imaging method according to claim 1 further includes: For each image reconstructed from the image, determine whether there is a closed region in each image; If a closed region exists in the image, and the contrast ratio between the closed region and the background region outside the closed region is less than a predetermined threshold, the energy range of the monitoring energy region corresponding to the image is adaptively adjusted.

3. The gamma camera imaging method according to claim 2, wherein, The adaptive adjustment includes: gradually increasing or decreasing the monitoring energy region to be adjusted in predetermined energy step sizes until the contrast between the closed region and the background region outside the closed region reaches the predetermined threshold.

4. The gamma camera imaging method according to claim 2 further includes: If there is no closed region in the image, the data of the monitoring energy region corresponding to the image will be discarded.

5. The gamma camera imaging method according to claim 2, further comprising: If there is no closed region in the image, the data of the monitoring energy region corresponding to the image will be discarded after a predetermined time.

6. The gamma camera imaging method according to claim 1, wherein, The overlay includes: superimposing the normalized images using different color channels to form the composite image.

7. A gamma camera imaging device, comprising: The selection module selects one or more energy ranges for each radioactive substance from the energy spectrum of one or more radioactive substances captured by the gamma camera as one or more monitoring energy regions for that radioactive substance. The image reconstruction module performs image reconstruction for the monitoring energy region of each of the one or more radioactive substances. The normalization module normalizes each image obtained through the image reconstruction. as well as The overlay module combines the normalized images to form a composite image. The selection module includes: The peak-finding module searches for peaks throughout the energy spectrum and compares the peak-finding results with the energies of each branch of radioactive materials recorded in the predetermined nuclide library to determine one or more radioactive materials. The branch determination module, for each of the one or more radioactive substances, determines the branches with higher branch ratios or lower energy among the branches of that radioactive substance as one or more branches of that radioactive substance to be monitored; and The energy region determination module, for each of the one or more branches of each radioactive material, determines the energy range centered on the center energy of that branch and with the full width at half maximum (FWHM) of the corresponding spectral peak of that branch as one of the one or more monitoring energy regions of that radioactive material.

8. The gamma camera imaging apparatus according to claim 7, wherein, The image reconstruction module includes: The closed region determination module determines whether there is a closed region in each of the images reconstructed from the images; and The energy range adjustment module adaptively adjusts the energy range of the monitoring energy range corresponding to the image if the contrast ratio between the closed region and the background region outside the closed region is less than a predetermined threshold when a closed region exists in the image.

9. The gamma camera imaging apparatus according to claim 8, wherein, The energy zone adjustment module is configured to: gradually attempt to expand or reduce the monitoring energy zone to be adjusted in units of a predetermined energy step, until the contrast between the closed region and the background region outside the closed region reaches the predetermined threshold.

10. The gamma camera imaging apparatus according to claim 8, wherein, The image reconstruction module also includes a discard module, which is configured to discard data of the monitoring energy region corresponding to the image when there is no closed region in the image.

11. The gamma camera imaging apparatus according to claim 8, wherein, The image reconstruction module also includes a discard module, which is configured to discard data of the monitoring energy region corresponding to the image after a predetermined time if there is no closed region in the image.

12. A gamma camera imaging device, comprising: Memory, which stores instructions; The processor is configured to execute the instructions stored in the memory to perform the method according to any one of claims 1-6.

13. A computer-readable storage medium storing instructions that, when executed by a processor, cause the processor to perform the method according to any one of claims 1-6.

14. A gamma camera, comprising a gamma camera imaging device as claimed in any one of claims 7-12.

Images