CN-116363024-B - Gamma camera imaging method and device

CN116363024BCN 116363024 BCN116363024 BCN 116363024BCN-116363024-B

Abstract

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

Inventors

Tuyagova
Hu Chunxuan
ZHAO KUN
JIN ZENGXUE
MA ZHIDAN

Assignees

同方威视技术股份有限公司

Dates

Publication Date: 20260512
Application Date: 20211228

Claims (14)

1. A gamma camera imaging method comprising: Selecting one or more energy ranges for each radioactive material from the energy spectrum of the one or more radioactive materials captured by the gamma camera as one or more monitoring energy regions for the radioactive material; image reconstruction can be performed separately for each of the one or more radioactive materials; Normalizing each image obtained by said image reconstruction, and The normalized individual images are superimposed to form a composite image, Wherein the selecting comprises: traversing peak searching from the energy spectrum, and comparing the peak searching result with the branch energy of the radioactive substance recorded by a preset nuclide library to determine one or more radioactive substances; For each of the one or more radioactive materials, determining the branch of the radioactive material that is higher or lower in energy than the branch of the radioactive material as the branch or branches of the radioactive material to be monitored, and For each of the one or more branches of each radioactive substance, an energy range centered on the center energy of the branch and having a width at half-height of the corresponding spectral peak of the branch is determined as one of one or more monitoring energy regions of the radioactive substance.
2. The gamma camera imaging method of claim 1, further comprising: Determining, for each image obtained by the image reconstruction, whether there is a closed region in each of the images; In the case where a closed region exists in the image, if the ratio of the contrast of the closed region to the background region other than the closed region is smaller 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 of claim 2 wherein the adaptively adjusting comprises stepwise attempting to amplify or reduce the monitored energy region to be adjusted in units of predetermined energy steps until the contrast of the enclosed region with a background region outside the enclosed region reaches the predetermined threshold.
4. The gamma camera imaging method of claim 2, further comprising: In the case where there is no closed area in the image, the data of the monitoring energy region corresponding to the image is discarded.
5. The gamma camera imaging method of claim 2, further comprising: In the case where there is no closed area in the image, after a predetermined time, the data of the monitoring energy area corresponding to the image is discarded.
6. The gamma camera imaging method of claim 1 wherein the superimposing includes superimposing the normalized individual images in different color channels to form the composite image.
7. A gamma camera imaging device comprising: A selection module that selects one or more energy ranges for each radioactive material from the energy spectrum of the one or more radioactive materials captured by the gamma camera as one or more monitoring energy regions for the radioactive material; an image reconstruction module for performing image reconstruction for each of the one or more radioactive materials; a normalization module for normalizing each image obtained by the image reconstruction, and A superposition module for superposing the normalized images to form a composite image, Wherein the selection module comprises: The peak searching module is used for traversing peak searching from the energy spectrum, and comparing the peak searching result with the branch energy of the radioactive substance recorded by a preset nuclide library so as to determine one or more radioactive substances; A branch determination module for determining, for each of the one or more radioactive materials, a branch of the one or more radioactive materials that has a higher branch or a lower energy branch of the one or more radioactive materials as one or more branches of the one or more radioactive materials to be monitored, and An energy region determination module determines, for each of the one or more branches of each radioactive substance, an energy range centered on a center energy of the branch and having a width at half-height of a corresponding spectral peak of the branch as one of one or more monitoring energy regions of the radioactive substance.
8. The gamma camera imaging device of claim 7, wherein the image reconstruction module comprises: a closed region determining module for determining whether there is a closed region in each of the images for each of the images obtained by the image reconstruction, and And the energy region adjusting module is used for adaptively adjusting the energy range of the monitoring energy region corresponding to the image if the contrast ratio of the closed region to the background region outside the closed region is smaller than a preset threshold value under the condition that the closed region exists in the image.
9. The gamma camera imaging device of claim 8, wherein the energy region adjustment module is configured to stepwise attempt to amplify or reduce a monitored energy region to be adjusted in units of predetermined energy steps until a contrast of the enclosed region with a background region outside the enclosed region reaches the predetermined threshold.
10. The gamma camera imaging device of claim 8, wherein the image reconstruction module further comprises a discard module configured to discard data of a monitoring energy region corresponding to the image if there is no enclosed region in the image.
11. The gamma camera imaging device of claim 8, wherein the image reconstruction module further comprises a discard module configured to discard data of a 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: a memory storing instructions; a processor 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 of any one of claims 1-6.
14. A gamma camera comprising the gamma camera imaging device of any of claims 7-12.

Description

Gamma camera imaging method and device Technical Field The present invention relates to the technical field of gamma cameras, and in particular, to a method and apparatus for imaging a gamma camera. Background The gamma camera is applied to the fields of nuclear safety and nuclear detection, and has the main functions of dynamically and statically imaging a radiation field of a radioactive substance contamination area and fusing the radiation field with an optical imaging image to obtain radioactive substance distribution information. Existing gamma cameras typically employ linear data processing methods, i.e., do not distinguish between received signals, and perform projection image restoration and original image reconstruction on all the signals of the active energy segments together. Because of quantization loss and approximation in the data processing process, statistical fluctuations and shadows are often present in the background of the bright spots after the image is reconstructed. And then screening the image area by using a brightness threshold value or a saliency threshold value and the like, and only selecting part of obvious imaging images to be fused with the optical images. Disclosure of Invention According to one aspect of the present application, there is provided a gamma camera imaging method comprising selecting one or more energy ranges of each radioactive substance from an energy spectrum of one or more radioactive substances captured by a gamma camera as one or more monitoring energy regions of the radioactive substance, reconstructing images for the monitoring energy regions of each of the one or more radioactive substances, normalizing respective images obtained by the image reconstruction, and superimposing the normalized respective images to form a composite image. In some embodiments, the selecting includes traversing peaks from the spectra, comparing the peak finding results to branch energies of the radioactive materials recorded by a predetermined library of nuclides to determine the one or more radioactive materials, determining, for each of the one or more radioactive materials, a branch of the radioactive material that is higher or lower in energy than the branch of the radioactive material as one or more branches of the radioactive material to be monitored, and determining, for each of the one or more branches of each of the radioactive materials, an energy range centered at a center energy of the branch and centered at a full width at half maximum of the corresponding spectral peak of the branch as one of one or more monitored energy regions of the radioactive material. In some embodiments, the gamma camera imaging method further comprises determining, for each image obtained by the image reconstruction, whether there is a closed region in each of the images, and if there is a closed region in the image, adaptively adjusting an energy range of a monitoring energy region corresponding to the image if a ratio of a contrast of the closed region to a background region other than the closed region is less than a predetermined threshold. In some embodiments, the adaptively adjusting includes progressively attempting to amplify or reduce in units of predetermined energy steps the monitored energy region to be adjusted until the contrast of the occluded region with a background region outside the occluded region reaches the predetermined threshold. In some embodiments, the gamma camera imaging method further comprises discarding data of a monitoring energy region corresponding to the image in the absence of a closed region in the image. In some embodiments, the gamma camera imaging method further comprises discarding data of a monitoring energy region corresponding to the image after a predetermined time in the absence of a closed region in the image. According to another aspect of the present application, there is provided a gamma camera imaging device including a selection module that selects one or more energy ranges of each radioactive substance from energy spectra of one or more radioactive substances captured by a gamma camera as one or more monitoring energy regions of the radioactive substance, an image reconstruction module that performs image reconstruction for each of the one or more radioactive substances, a normalization module that normalizes respective images obtained by the image reconstruction, and a superimposition module that superimposes the normalized respective images to form a composite image. In some embodiments, the selection module includes a peak finding module that traverses peaks from the energy spectrum, compares the peak finding results with branch energies of the radioactive materials recorded in a predetermined nuclide library to determine the one or more radioactive materials, a branch determination module that determines, for each of the one or more radioactive materials, a branch of the radioactive material that is higher or lower in energy than