Crystal array positioning method and device
By performing light leakage or absorption treatment on the crystal surface or reflective layer, and determining the crystal position with Gaussian fitting, the operation complex and cost-effectiveness of the multi-to-one coupling method in the prior art is solved, and the spatial resolution of the PET scanner is improved. System simplification.
Patent Information
- Application Number
- CN202411122443.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-15
- Publication Date
- 2024-12-27
AI Technical Summary
In the prior art, the many-to-one coupling method between crystals and photodetectors requires external light guides to locate the crystal position, which is complex and costly, resulting in artifact problems and increased system manufacturing costs.
By performing light leakage or light absorption treatment on the crystal surface or reflective layer, different degrees of light leakage or light absorption generate an offset energy spectrum, combined with Gaussian fitting, the crystal position is determined, the dependence on the light guide is eliminated, and the crystal position is achieved is accurate.
It improves the spatial resolution of the detector, reduces the operation difficulty and device production cost, avoids artifact problems, and simplifies system design.
Smart Images
Figure CN119199948A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of many-to-one coupled crystal arrays, and in particular to a crystal array positioning method and device. Background Art
[0002] The spatial resolution of PET (Positron Emission Computed Tomography) systems is directly limited by the resolution of the detector. In order to ensure the detection efficiency of gamma photons, current clinical PET scanners generally use detectors based on narrow and long LYSO scintillation crystal arrays, coupled with photodetector arrays such as silicon photomultipliers (SiPMs).
[0003] In principle, the physical size of the detector element usually plays a dominant role in determining the resolution. Using a detector module composed of smaller detector components (also called detector pixelation) can increase the number of samples collected in the spatial domain, thereby achieving higher spatial resolution. However, smaller detector blocks will mean more complex scintillation crystal processing technology, and continuing to use the one-to-one coupling method between crystals and SiPMs means that there are higher requirements for the volume and performance of optoelectronic components.
[0004] The one-to-one coupling between the crystal and the SiPM in the prior art will produce a serious dead zone effect, causing serious artifact problems during imaging and greatly increasing the manufacturing cost of the system. The current many-to-one coupling method will increase the complexity and design difficulty of the back-end readout electronic circuit, and the data obtained will be more complex. It is necessary to connect other optical guides to determine the crystal position, which is not only difficult to operate, but also very costly. Summary of the invention
[0005] The present invention provides a crystal array positioning method and device, which are used to solve the defects of the prior art that the many-to-one coupling mode between crystals and photodetectors requires an external light guide to locate the crystal position, which is complicated to operate and has high cost. The present invention realizes the positioning of the crystal position only by processing the crystal surface or the reflective layer, without the need for an external light guide, thereby reducing cost and complexity and improving the spatial resolution of the detector.
[0006] The present invention provides a crystal array positioning method, comprising:
[0007] According to the scintillation pulses generated by each crystal in the crystal array, the original energy spectrum of each crystal is obtained, and the reflective layer wrapped around the crystal has been subjected to different degrees of light leakage or light absorption treatment, so that the visible light photons generated after the gamma photon deposition in the crystal have different degrees of light leakage or light absorption;
[0008] Determining the energy spectrum position of the energy peak in the original energy spectrum of each crystal, the energy spectrum position of the energy peak corresponding to each crystal is different, and the degree of light leakage or light absorption treatment performed on the reflective layer of each crystal is different;
[0009] The number of the crystal associated with the energy spectrum position corresponding to each crystal is searched from the predetermined association relationship between the energy spectrum position of the energy peak and the number of the crystal.
[0010] According to a crystal array positioning method provided by the present invention, there are openings in the light leakage area of the reflective layer of the crystal, or light absorbing material is added between the light leakage area and the crystal, so that the visible light photons generated by the crystal cannot be completely reflected.
[0011] According to a crystal array positioning method provided by the present invention, for different crystals, at least one of the position, size and number of the light leakage areas is different.
[0012] According to a crystal array positioning method provided by the present invention, the light absorbing area of the reflective layer of the crystal is replaced with a light absorbing material or the crystal corresponding to the light absorbing area is processed into a frosted surface, so that the crystal absorbs light.
[0013] According to a crystal array positioning method provided by the present invention, for different crystals, at least one of the position, size and number of the light absorption regions is different.
[0014] According to a crystal array positioning method provided by the present invention, the step of determining the energy spectrum position of the energy peak in the original energy spectrum of each crystal comprises:
[0015] Performing Gaussian fitting on the energy peak in the original energy spectrum to obtain a Gaussian function of the energy peak;
[0016] The energy spectrum position of the energy peak in the original energy spectrum is determined according to the mean value and / or variance of the Gaussian function.
[0017] The present invention also provides a crystal array positioning device, comprising:
[0018] An acquisition module is used to acquire the original energy spectrum of each crystal in the crystal array according to the scintillation pulses generated by each crystal, wherein the reflective layer wrapped around the crystal has been subjected to different degrees of light leakage or light absorption treatment, so that the visible light photons generated after the γ photon deposition in the crystal have different degrees of light leakage or light absorption;
[0019] A calculation module, used to determine the energy spectrum position of the energy peak in the original energy spectrum of each crystal, the energy spectrum position of the energy peak corresponding to each crystal is different, and the degree of light leakage or light absorption treatment performed on the reflective layer of each crystal is different;
[0020] The search module is used to search the crystal number associated with the energy spectrum position corresponding to each crystal from the predetermined association relationship between the energy spectrum position of the energy peak and the crystal number.
[0021] The present invention also provides a PET scanner, comprising the above-mentioned crystal array positioning device, a crystal array and a photodetector array;
[0022] The crystals in the crystal array are coupled to the photodetectors in the photodetector array;
[0023] The crystal array positioning device is used to determine the crystal coupled to the photodetector.
[0024] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, any one of the crystal array positioning methods described above is implemented.
[0025] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the crystal array positioning method as described in any one of the above is implemented.
[0026] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the computer program implements any of the above-mentioned crystal array positioning methods.
[0027] The crystal array positioning method and device provided by the present invention, by changing the structure of the crystal outer reflection film, produces different degrees of leakage or absorption of visible light photons generated after γ photon deposition in the crystal, and obtains a shifted energy spectrum. Since different degrees of leakage or absorption bring different shifts to the energy spectrum, the crystal positions where different γ photons are deposited can be distinguished through the different Gaussian fitting peak positions of the energy spectrum, thereby completing the positioning of the pixelated crystal, physically reducing the size of the detector components, improving the spatial resolution, eliminating the use of light guides, and reducing the difficulty of operation and the cost of device manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0029] Figure 1 It is a schematic diagram of the process of the crystal array positioning method provided by the present invention;
[0030] Figure 2 It is a schematic diagram of performing light leakage or light absorption processing on the reflective layer of the crystal in the crystal array positioning method provided by the present invention;
[0031] Figure 3 It is a schematic diagram of position changes of energy peaks when the mean values are different in the crystal array positioning method provided by the present invention;
[0032] Figure 4 It is a schematic diagram comparing the energy spectrum obtained in the experiment of fully enclosing the crystal without opening a window and the energy spectrum obtained when the crystal side window is opened and light leaks in the crystal array positioning method provided by the present invention;
[0033] Figure 5 It is a structural schematic diagram of the crystal array positioning device provided by the present invention;
[0034] Figure 6 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION
[0035] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0036] PET technology is based on radioactive tracer molecular imaging, which can reflect the genetic, molecular, metabolic and functional status of lesions. It is currently the most widely used radioactive imaging technology and an important tool in preclinical research. Although PET has excellent molecular specificity and sensitivity, its spatial resolution is relatively poor compared with other clinical imaging technologies such as CT (Computed Tomography) and MRI (Magnetic Resonance Imaging). The high spatial resolution and high sensitivity of PET scanners mean minimizing patient doses, reasonably shortening scanning times, and obtaining high image quality, so that physiological processes can be tracked and quantified more accurately, thereby greatly improving the screening and detection of early diseases.
[0037] Current clinical PET scanners generally use a structure that couples detectors based on a narrow and long LYSO scintillation crystal array with a photodetector array such as SiPM. The one-to-one coupling between the crystal and SiPM will bring the following problems:
[0038] (1) Further improving resolution using pixelated detectors is not only expensive, but also has more connections between detector components and modules, which reduces sensitivity and can produce artifacts in some cases. The smaller area of SiPMs means that more photosensitive cells are affected by edge effects, resulting in more severe dead zone effects. Similarly, the combination of non-collinearity, positron range, entry into the detector ring, and decoding errors in the detector module will inevitably lead to a serious degradation of important performance parameters such as timing, energy resolution, and sensitivity.
[0039] (2) If the one-to-one coupling method is changed to a one-to-many coupling method, the complexity and design difficulty of the back-end readout electronic circuit will increase, and the data obtained will be more complex. In addition, the simple many-to-one coupling method requires external connection of other functional parts, such as an external light guide that refracts photons on the top of the crystal array. The crystal position is determined by refracting some photons into other crystals and leaking other photons obtained by the SiPM that is not coupled to the crystal. This method requires the addition of a complex light guide, which is not only difficult to operate, but also very costly.
[0040] Combine the following Figure 1 A crystal array positioning method of the present invention is described, comprising:
[0041] Step 101, obtaining the original energy spectrum of each crystal in the crystal array according to the scintillation pulses generated by each crystal, wherein the reflective layer wrapped around the crystal has been subjected to different degrees of light leakage or light absorption treatment, so that the visible light photons generated after the γ photon deposition in the crystal have different degrees of light leakage or light absorption;
[0042] The scintillator crystal in the crystal array is a material that has the ability to absorb gamma rays and convert part of the absorbed energy into visible or ultraviolet photons. As a result, each scintillator crystal will produce a corresponding short pulse of photons due to the interaction between the material and the gamma rays, namely the scintillation pulse. The intensity of the scintillation pulse is usually proportional to the energy deposited in the scintillator crystal, which is sensed by the photodetector and converted into an electrical signal.
[0043] Except for the surface coupled with the photodetector (such as SiPM), the other surfaces of the crystal are completely wrapped by a reflective layer. The reflective material used in the reflective layer is Teflon, aluminum foil or barium sulfate.
[0044] The reflective layer of the crystal is treated with different degrees of light leakage or light absorption, such as changing the wrapping area of the reflective layer on the crystal, which will cause different degrees of light leakage or light absorption of visible light photons generated after γ photon deposition in the crystal. This embodiment does not specifically limit the treatment method.
[0045] Because the propagation of visible light photons in the crystal is isotropic, the probability of each scintillation pulse leaking or absorbing photons is the same after light leakage or absorption. Therefore, by integrating the scintillation pulses after light leakage or absorption, the standard original energy spectrum can still be obtained, that is, an energy spectrum with Compton scattering peak, 511kev peak and 1274.5kev peak.
[0046] Step 102, determining the energy spectrum position of the energy peak in the original energy spectrum of each crystal, the energy spectrum position of the energy peak corresponding to each crystal is different, and the degree of light leakage or light absorption treatment performed on the reflective layer of each crystal is different;
[0047] Due to light leakage or absorption, the energy spectrum position of a certain energy peak corresponding to the original energy spectrum will change, such as the 511kev peak position.
[0048] In the case of different light leakage or light absorption levels, the energy spectrum positions of the energy peaks are different. According to the energy spectrum positions of one or more energy peaks, the crystal where deposition occurs can be reversely determined to achieve the purpose of accurately locating the crystal in the case of many-to-one coupling.
[0049] Step 103 : searching the crystal number associated with the energy spectrum position corresponding to each crystal from the predetermined association relationship between the energy spectrum position of the energy peak and the crystal number.
[0050] Different crystals have different degrees of light leakage or light absorption, which makes the energy spectrum positions of energy peaks corresponding to different crystals different. Before the crystals form a crystal array, a single crystal can be tested to obtain the energy spectrum position of the energy peak under different degrees of light leakage or light absorption of the reflective layer, and form a correspondence table. The corresponding table stores the correlation between the energy spectrum position of the energy peak and the crystal number, thereby realizing the encoding of the crystal. In the actual experiment after the crystals form a crystal array, the energy spectrum position of the energy peak corresponding to each crystal can be tested experimentally, and the number of the crystal where deposition occurs can be queried from the corresponding relationship shown in the table.
[0051] Compared with one-to-one coupling, the size of the detector components is only physically reduced, but more connection points between detector components and modules are introduced, which reduces the sensitivity. The area of the photodetector is smaller, resulting in more serious dead zone effects and other problems. This embodiment maintains the normal size of the photodetector (such as SiPM) and reduces the introduction of unnecessary variables.
[0052] For a detector with a sheet crystal structure, this embodiment can maintain the length of the crystal, thereby ensuring the detection efficiency of the crystal and not affecting the subsequent calculation of the time resolution.
[0053] This embodiment changes the structure of the reflective film outside the crystal to produce different degrees of leakage or absorption of visible light photons generated after γ photon deposition in the crystal, and obtains a shifted energy spectrum. Since different levels of leakage or absorption bring different shifts to the energy spectrum, the crystal positions where different γ photons are deposited can be distinguished through the different Gaussian fitting peak positions of the energy spectrum, thereby completing the positioning of the pixelated crystal, physically reducing the size of the detector components, improving the spatial resolution, eliminating the use of light guides, and reducing the difficulty of operation and the cost of device manufacturing.
[0054] On the basis of the above embodiments, in this embodiment, there are openings in the light leakage area of the reflective layer of the crystal, or light absorbing materials are added between the light leakage area and the crystal, so that the visible light photons generated by the crystal cannot be completely reflected.
[0055] Some specific parts are reserved in the reflective layer of the crystal for opening (ie, not wrapped with reflective material), so as to achieve light leakage processing of the reflective layer.
[0056] The method of light leakage is not only to change the structure of the reflective material applied on the outside of the watch, but also to add light-absorbing material between the reflective material and the crystal, at the position where light leakage is needed, and then apply reflective material on the outside. This will help to fix the light-absorbing material and also help with the subsequent array formation of crystal strips.
[0057] On the basis of the above embodiment, in this embodiment, for different crystals, at least one of the position, size and number of the light leakage areas is different.
[0058] Based on the above embodiment, in this embodiment, at least one portion of the reflective layer of the crystal is replaced with a light absorbing material. The light absorbing area of the reflective layer of the crystal is replaced with a light absorbing material or the crystal corresponding to the light absorbing area is processed into a frosted surface so that the crystal absorbs light.
[0059] Replace the reflective material at specific locations on the crystal with a light-absorbing material.
[0060] The light absorption method can also process specific positions of the crystal into frosted surfaces. The frosted surface also absorbs light through diffuse reflection, and directly processes the crystal, avoiding other variables introduced by subsequent processing.
[0061] On the basis of the above embodiment, in this embodiment, for different crystals, at least one of the position, size and quantity of the light absorbing material is different.
[0062] The schematic diagram of the light leakage or light absorption treatment of the reflective layer of the crystal is as follows Figure 2 The white part is the reflective material covered by the full film, and the blue part is the reflective material with holes, directly exposing the crystal surface or the light-absorbing material replacing the reflective material.
[0063] Figure 2 The left middle diagram is a schematic diagram of the outer coating of the crystal in the traditional state, which is fully covered with reflective material. Figure 2 The second to sixth diagrams from the left are schematic diagrams of several hole-opening methods or light-absorbing material replacement methods, which do not represent all treatment methods. The location, size and number of holes or light-absorbing material replacements can be changed and combined at will according to actual needs.
[0064] On the basis of the above embodiments, the method of determining the energy spectrum position of the energy peak in the original energy spectrum of each crystal in this embodiment includes:
[0065] Performing Gaussian fitting on the energy peak in the original energy spectrum to obtain a Gaussian function of the energy peak;
[0066] The energy spectrum position of the energy peak in the original energy spectrum is determined according to the mean value and / or variance of the Gaussian function.
[0067] After integrating the scintillation pulses generated by each crystal read out by the photoelectric device, the original energy spectrum of each crystal is plotted. The 511kev energy peak in the original energy spectrum of each crystal can be fitted to obtain the Gaussian function of the energy peak.
[0068] The expression of Gaussian function is Its shape is like an upside-down bell. Parameter a refers to the peak value of the Gaussian curve; b is the mean, which represents its corresponding horizontal coordinate; c is the variance, sometimes also called the Gaussian RMS (Root Mean Square) width, which controls the width of the "bell". Therefore, the mean and variance of the Gaussian function determine its position and shape.
[0069] The mean or variance of the Gaussian function can be directly used as the energy spectrum position of the energy peak. The mean and variance of the Gaussian function can also be used as the energy spectrum position of the energy peak. This embodiment is not specifically limited. For example, by the difference in the mean and variance of the Gaussian fitting of the 511kev peak, the position of different Gaussian peaks can be clearly determined.
[0070] The original energy spectrum obtained after different light leakage or light absorption treatments on the reflective layer of the crystal has different positions and widths of energy peaks, such as Figure 3 shown. Figure 3 is the position change of the Gaussian peak when the mean value is different.
[0071] By conducting experiments on crystals with different hole opening methods or different light-absorbing material replacement methods, different groups of energy spectra are obtained, and Gaussian fitting functions of energy spectra of different groups are distinguished. Figure 4 (a) is the energy spectrum obtained by the crystal full encapsulation without window opening experiment. Figure 4(b) is the energy spectrum obtained when a window is opened on the side of the crystal to allow light to leak. It can be seen that the two energy spectra are very uniform in shape. Opening the window will not have a significant impact on the obtained energy spectrum, and will not affect subsequent steps such as the calculation of time resolution.
[0072] The red Gaussian peaks shown in the figure can be used to distinguish the crystal position where deposition occurs, thereby eliminating the use of additional parts such as light guides, greatly reducing the complexity of crystal position positioning and reducing the cost of structural integration.
[0073] The crystal array positioning device provided by the present invention is described below. The crystal array positioning device described below and the crystal array positioning method described above can be referenced to each other.
[0074] like Figure 5 As shown, the device includes an acquisition module 501, a calculation module 502 and a search module 503, wherein:
[0075] The acquisition module 501 is used to acquire the original energy spectrum of each crystal in the crystal array according to the scintillation pulses generated by each crystal, and the reflective layer wrapped around the crystal has been subjected to different degrees of light leakage or light absorption treatment, so that the visible light photons generated after the γ photon deposition in the crystal have different degrees of light leakage or light absorption;
[0076] The calculation module 502 is used to determine the energy spectrum position of the energy peak in the original energy spectrum of each crystal, and the energy spectrum position of the energy peak corresponding to each crystal is different due to different degrees of light leakage or light absorption treatment performed on the reflective layer of each crystal;
[0077] The search module 503 is used to search the number of the crystal associated with the energy spectrum position corresponding to each crystal from the predetermined association relationship between the energy spectrum position of the energy peak and the number of the crystal.
[0078] This embodiment changes the structure of the reflective film outside the crystal to produce different degrees of leakage or absorption of visible light photons generated after γ photon deposition in the crystal, and obtains a shifted energy spectrum. Since different levels of leakage or absorption bring different shifts to the energy spectrum, the crystal positions where different γ photons are deposited can be distinguished through the different Gaussian fitting peak positions of the energy spectrum, thereby completing the positioning of the pixelated crystal, physically reducing the size of the detector components, improving the spatial resolution, eliminating the use of light guides, and reducing the difficulty of operation and the cost of device manufacturing.
[0079] The present invention also provides a PET scanner, comprising the crystal array positioning device, the crystal array and the photodetector array in the above embodiment;
[0080] The crystals in the crystal array are coupled many-to-one or one-to-one with the photodetectors in the photodetector array;
[0081] The crystal array positioning device is used to determine the crystal coupled to the photodetector.
[0082] In order to ensure that the many-to-one coupling can still distinguish pixel crystals, this embodiment does not require an external light guide. It only processes the reflective layer on the surface of the crystal to distinguish whether the gamma photons are deposited on one of the multiple crystals coupled to the photodetector, thereby reducing the cost and complexity and improving the spatial resolution of the detector.
[0083] Figure 6 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 6 As shown, the electronic device may include: a processor 610, a communication interface 620, a memory 630 and a communication bus 640, wherein the processor 610, the communication interface 620 and the memory 630 communicate with each other through the communication bus 640. The processor 610 may call the logic instructions in the memory 630 to execute the crystal array positioning method, which includes: obtaining the original energy spectrum of each crystal according to the scintillation pulse generated by each crystal in the crystal array, wherein the reflection layer wrapped outside the crystal has been subjected to different degrees of light leakage or light absorption treatment, so that the visible light photons generated after the γ photon deposition in the crystal produce different degrees of light leakage or light absorption; determining the energy spectrum position of the energy peak in the original energy spectrum of each crystal, wherein the energy spectrum position corresponding to each crystal is different, and the degree of light leakage or light absorption treatment of the reflection layer of each crystal is different; and searching the number of the crystal associated with the energy spectrum position corresponding to each crystal from the association relationship between the energy spectrum position of the energy peak and the number of the crystal determined in advance.
[0084] In addition, the logic instructions in the above-mentioned memory 630 can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk.
[0085] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the crystal array positioning method provided by the above-mentioned methods, which method includes: obtaining the original energy spectrum of each crystal according to the scintillation pulse generated by each crystal in the crystal array, the reflective layer wrapped around the crystal has been subjected to different degrees of light leakage or light absorption treatment, so that the visible light photons generated after γ photon deposition in the crystal produce different degrees of light leakage or light absorption; determining the energy spectrum position of the energy peak in the original energy spectrum of each crystal, the energy spectrum position of the energy peak corresponding to each crystal is different, and the degree of light leakage or light absorption treatment of the reflective layer of each crystal is different; from the predetermined correlation relationship between the energy spectrum position of the energy peak and the number of the crystal, searching for the number of the crystal associated with the energy spectrum position corresponding to each crystal.
[0086] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the crystal array positioning method provided by the above-mentioned methods, the method comprising: obtaining the original energy spectrum of each crystal according to the scintillation pulse generated by each crystal in the crystal array, the reflective layer wrapped around the crystal having undergone different degrees of light leakage or light absorption treatment, so that the visible light photons generated after γ photon deposition in the crystal produce different degrees of light leakage or light absorption; determining the energy spectrum position of the energy peak in the original energy spectrum of each crystal, the energy spectrum position of the energy peak corresponding to each crystal is different, and the degree of light leakage or light absorption treatment of the reflective layer of each crystal is different; and searching for the number of the crystal associated with the energy spectrum position corresponding to each crystal from the association relationship between the predetermined energy spectrum position of the energy peak and the number of the crystal.
[0087] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.
[0088] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.
[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A crystal array positioning method, characterized in that: include: According to the scintillation pulses generated by each crystal in the crystal array, the original energy spectrum of each crystal is obtained, and the reflective layer wrapped around the crystal has been subjected to different degrees of light leakage or light absorption treatment, so that the visible light photons generated after the gamma photon deposition in the crystal have different degrees of light leakage or light absorption; Determining the energy spectrum position of the energy peak in the original energy spectrum of each crystal, the energy spectrum position of the energy peak corresponding to each crystal is different, and the degree of light leakage or light absorption treatment performed on the reflective layer of each crystal is different; The number of the crystal associated with the energy spectrum position corresponding to each crystal is searched from the predetermined association relationship between the energy spectrum position of the energy peak and the number of the crystal.
2. The crystal array positioning method according to claim 1, characterized in that: There are openings in the light leakage area of the reflective layer of the crystal, or light absorbing materials are added between the light leakage area and the crystal, so that the visible light photons generated by the crystal cannot be completely reflected.
3. The crystal array positioning method according to claim 2, characterized in that: For different crystals, at least one of the position, size and number of the light leakage areas is different.
4. The crystal array positioning method according to claim 1, characterized in that: The light absorbing area of the reflective layer of the crystal is replaced with a light absorbing material or the crystal corresponding to the light absorbing area is processed into a frosted surface, so that the crystal absorbs light.
5. The crystal array positioning method according to claim 4, characterized in that: For different crystals, at least one of the position, size and number of the light absorption regions is different.
6. The crystal array positioning method according to any one of claims 1 to 5, characterized in that: The step of determining the energy spectrum position of the energy peak in the original energy spectrum of each crystal comprises: Performing Gaussian fitting on the energy peak in the original energy spectrum to obtain a Gaussian function of the energy peak; The energy spectrum position of the energy peak in the original energy spectrum is determined according to the mean value and / or variance of the Gaussian function.
7. A crystal array positioning device, characterized in that: include: An acquisition module is used to acquire the original energy spectrum of each crystal in the crystal array according to the scintillation pulses generated by each crystal, wherein the reflective layer wrapped around the crystal has been subjected to different degrees of light leakage or light absorption treatment, so that the visible light photons generated after the γ photon deposition in the crystal have different degrees of light leakage or light absorption; A calculation module, used to determine the energy spectrum position of the energy peak in the original energy spectrum of each crystal, the energy spectrum position of the energy peak corresponding to each crystal is different, and the degree of light leakage or light absorption treatment performed on the reflective layer of each crystal is different; The search module is used to search the crystal number associated with the energy spectrum position corresponding to each crystal from the predetermined association relationship between the energy spectrum position of the energy peak and the crystal number.
8. A PET scanner, characterized in that: The device comprises the crystal array positioning device, the crystal array and the photodetector array as claimed in claim 7; The crystals in the crystal array are coupled to the photodetectors in the photodetector array; The crystal array positioning device is used to determine the crystal coupled to the photodetector.
9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the crystal array positioning method according to any one of claims 1 to 6 is implemented.
10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the crystal array positioning method according to any one of claims 1 to 6 is implemented.