Static ct imaging system and method

Abstract

The application provides a kind of static CT imaging system, comprising: scan channel, the scan channel is used to transport scanned object through the scan area of the static CT imaging system;Multiple distributed light sources;And detector, wherein, multiple the distributed light source at least includes a kind of light source and two kinds of light sources, the energy of the first ray emitted by the target point of the kind of light source is higher than the energy of the second ray emitted by the target point of the two kinds of light sources, the first ray passes through scanned object in the scan area along first ray path, the second ray passes through scanned object in the scan area along second ray path, the attenuation of the first ray along the extension direction of the first ray path to scanned object is different from the attenuation of the second ray along the extension direction of the second ray path to scanned object.The application also provides a kind of static CT imaging method.

Description

Technical Field

[0001] This disclosure relates to the field of radiation scanning technology, and more specifically, to a static CT imaging system and a static CT imaging method. Background Technology

[0002] Computed tomography (CT) systems are widely used in various fields such as industrial inspection, security checks, and biomedical imaging. Traditional CT systems use a single-target X-ray source to emit radiation and reconstruct the internal structure of an object by analyzing the attenuation of the radiation. However, in some practical applications, the radiation attenuation of the target object is often much stronger in one direction than in others, such as when there is an uneven distribution of high-density or high-absorption materials. In such cases, if the same energy radiation is used in all scanning directions, it is easy for images to be missing or artifacts to occur due to the inability to penetrate in certain directions. It may also lead to resource waste and increased equipment costs due to excessively high radiation energy in some directions. Summary of the Invention

[0003] In view of the above problems, this disclosure provides a static CT imaging system and a static CT imaging method.

[0004] A first aspect of this disclosure provides a static CT imaging system, comprising: a scanning channel for conveying an object to be scanned through a scanning area of ​​the static CT imaging system; a plurality of distributed light sources, at least one of the distributed light sources including a plurality of target points configured to emit rays respectively; and a detector for detecting rays emitted from the plurality of distributed light sources and passing through the object to be scanned, wherein the plurality of distributed light sources include at least a first type of light source and a second type of light source, wherein the energy of a first ray emitted by a target point of the first type of light source is higher than the energy of a second ray emitted by a target point of the second type of light source, the first ray passing through the object to be scanned in the scanning area along a first ray path, the second ray passing through the object to be scanned in the scanning area along a second ray path, and the attenuation of the first ray by the object to be scanned along the extension direction of the first ray path being different from the attenuation of the second ray by the object to be scanned along the extension direction of the second ray path.

[0005] According to embodiments of this disclosure, the first type of light source is arranged on at least one side of the scanning area based on the shape of the scanned object, and the second type of light source is arranged on at least one side of the scanning area based on the shape of the scanned object; or, the first type of light source is arranged on at least one side of the scanning area based on the statistical attenuation path of the scanned object in the target CT imaging scene, and the second type of light source is arranged on at least one side of the scanning area based on the statistical attenuation path of the scanned object in the target CT imaging scene.

[0006] According to an embodiment of this disclosure, when viewed along the extension direction of the scanning channel, the scanning area includes at least a first side, a second side, and a third side. The first side and the second side are arranged adjacent to each other, and the first side and the third side are arranged opposite to each other. The second side is provided with one of the first type of light source and the second type of light source, and at least one of the first side and the third side is provided with the other of the first type of light source and the second type of light source.

[0007] According to an embodiment of this disclosure, when viewed along the extension direction of the scanning channel, the scanning area includes at least a first side, a second side, and a third side. The first side and the second side are arranged adjacent to each other, and the first side and the third side are arranged opposite to each other. The first type of light source and the second type of light source are provided on the same side of the scanning area.

[0008] According to embodiments of this disclosure, a combination of light sources, including the first type of light source and the second type of light source, is arranged on the first side, the second side, and the third side to form a semi-enclosed structure surrounding the scanning area.

[0009] According to embodiments of this disclosure, the first type of light source is disposed on the first side and the third side, and the second type of light source is disposed on the second side; or the second type of light source is disposed on the first side and the third side, and the first type of light source is disposed on the second side.

[0010] According to embodiments of this disclosure, the two types of light sources include a first type of sub-light source and a second type of sub-light source, with the first type of light source and the first type of sub-light source disposed on the first side and the third side, and the second type of sub-light source disposed on the second side; or the two types of light sources include a first type of sub-light source and a second type of sub-light source, with the first type of light source and the first type of sub-light source disposed on the second side, and the second type of sub-light source disposed on the first side and the third side.

[0011] According to embodiments of this disclosure, the first type of light source and the second type of light source are disposed in a plane perpendicular to the transport direction of the scanned object; or the first type of light source and the second type of light source are disposed in multiple parallel planes perpendicular to the transport direction of the scanned object.

[0012] According to embodiments of this disclosure, the operating voltage of the second type of light source is a fixed voltage M2, and the operating voltage of the first type of light source is selected based on a target adjustment range.

[0013] According to an embodiment of this disclosure, the lower limit of the target adjustment range is M2, the upper limit of the target adjustment range is M1, and the difference between M1 and M2 is greater than or equal to 20kV.

[0014] According to embodiments of this disclosure, the first type of light source includes N1 target points, and the second type of light source includes N2 target points, where N1 and N2 are both positive integers greater than or equal to 2.

[0015] According to embodiments of this disclosure, when viewed along the extension direction of the scanning channel, the length of the target points in the first type of light source and / or the second type of light source at least covers the length on either side of the scanning area.

[0016] According to embodiments of this disclosure, the static CT imaging system further includes a control interface for an operator to set the operating voltage of the light source according to the properties of the object being scanned.

[0017] According to embodiments of this disclosure, the static CT imaging system further includes an auxiliary sensing device and a controller, the controller setting the operating voltage of the light source based on the contour information of the scanned object acquired by the auxiliary sensing device.

[0018] According to an embodiment of this disclosure, the distributed light source is distributed on L beam surfaces along the transport path of the scanned object, where L is a positive integer greater than or equal to 2. The operating voltage of the distributed light source on the first beam surface is set to M1, and the operating voltage of the distributed light source on the second to L beam surfaces is set according to the ray attenuation degree corresponding to the previous beam surface.

[0019] According to an embodiment of this disclosure, the static CT imaging system further includes a controller configured to: perform correction processing on the first projection data obtained by scanning with the first type of light source, and perform image reconstruction based on the corrected first projection data and the second projection data obtained by scanning with the second type of light source, so as to obtain a target reconstructed image.

[0020] According to embodiments of this disclosure, the detectors are arranged on at least two of the first side, the second side, and the third side.

[0021] A second aspect of this disclosure provides a static CT imaging method, wherein the static CT imaging method is used in a static CT imaging system, the static CT imaging system including a scanning area, a plurality of distributed light sources and a detector, the plurality of distributed light sources including at least a first type of light source and a second type of light source, wherein the energy of a first ray emitted from a target point of the first type of light source is higher than the energy of a second ray emitted from a target point of the second type of light source, the static CT imaging method comprising: obtaining first projection data in response to the first ray passing through a scanned object in the scanning area along a first ray path; obtaining second projection data in response to the second ray passing through a scanned object in the scanning area along a second ray path; and based on the first projection... The first projection data and the second projection data are processed; and image reconstruction is performed based on the processed projection data to obtain a target reconstructed image. The data processing based on the first projection data and the second projection data includes: performing correction processing on at least one of the first projection data and the second projection data using a mapping relationship to obtain corrected first projection data and / or corrected second projection data. The mapping relationship is used to: map the first projection data to the range where the second projection data is located, map the second projection data to the range where the first projection data is located, or map the first projection data and the second projection data to the range where a pre-acquired third projection data is located.

[0022] According to embodiments of this disclosure, the data processing based on the first projection data and the second projection data specifically includes: acquiring third projection data and fourth projection data obtained by scanning at least one reference material with the first type of light source and the second type of light source under preset energy conditions; constructing an initial mapping relationship between the first type of light source and the second type of light source based on the third projection data and the fourth projection data, wherein the initial mapping relationship represents mapping the third projection data to the range of the fourth projection data; performing an initial correction on the first projection data based on the initial mapping relationship to obtain initially corrected first projection data; constructing an initial reconstructed image based on the initially corrected first projection data and the second projection data; calculating a theoretical attenuation value based on the initial reconstructed image, updating the initial mapping relationship based on the theoretical attenuation value to obtain an updated mapping relationship; performing a second correction on the initially corrected first projection data based on the updated mapping relationship to obtain second-corrected first projection data; and repeating the process of constructing the reconstructed image, updating the mapping relationship, and correcting the first projection data until a preset iteration stop condition is reached to obtain first projection data after multiple corrections.

[0023] According to embodiments of this disclosure, the step of reconstructing the image based on the processed projection data to obtain the target reconstructed image specifically includes: constructing the target reconstructed image based on the first projection data and the second projection data after multiple corrections.

[0024] According to embodiments of this disclosure, the data processing based on the first projection data and the second projection data specifically includes: acquiring third projection data and fourth projection data obtained by scanning at least one reference material with the first type of light source and the second type of light source under preset energy conditions; constructing an initial mapping relationship between the first type of light source and the second type of light source based on the third projection data and the fourth projection data, wherein the initial mapping relationship represents mapping the fourth projection data to the range of the third projection data; performing initial correction on the second projection data based on the initial mapping relationship to obtain initially corrected second projection data; constructing an initial reconstructed image based on the initially corrected second projection data and the first projection data; calculating a theoretical attenuation value based on the initial reconstructed image, updating the initial mapping relationship based on the theoretical attenuation value to obtain an updated mapping relationship; performing a second correction on the initially corrected second projection data based on the updated mapping relationship to obtain a second corrected second projection data; and repeating the process of constructing the reconstructed image, updating the mapping relationship, and correcting the second projection data until a preset iteration stop condition is reached to obtain second projection data after multiple corrections.

[0025] According to embodiments of this disclosure, the step of reconstructing the image based on the processed projection data to obtain the target reconstructed image specifically includes: constructing the target reconstructed image based on the second projection data after multiple corrections and the first projection data.

[0026] According to embodiments of this disclosure, the data processing based on the first projection data and the second projection data specifically includes: acquiring third projection data and fourth projection data obtained by scanning at least one reference material with the first type of light source and the second type of light source under preset energy conditions; constructing an initial mapping relationship between the first type of light source and the second type of light source based on the third projection data and the fourth projection data, wherein the initial mapping relationship represents mapping the fourth projection data and the third projection data to the range of pre-acquired target projection data; and performing initial correction on the first projection data and the second projection data based on the initial mapping relationship to obtain initially corrected first projection data and initially corrected second projection data. The process involves: constructing an initial reconstructed image based on the second and first projection data after initial correction; calculating a theoretical attenuation value based on the initial reconstructed image; updating the initial mapping relationship based on the theoretical attenuation value to obtain an updated mapping relationship; re-correcting the first and second projection data based on the updated mapping relationship to obtain re-corrected first and second projection data; and repeating the process of constructing the reconstructed image, updating the mapping relationship, and correcting the first and second projection data until a preset iteration stop condition is reached, thereby obtaining multiple-corrected first and second projection data.

[0027] According to embodiments of this disclosure, the step of reconstructing the image based on the processed projection data to obtain the target reconstructed image specifically includes: constructing the target reconstructed image based on the first projection data after multiple corrections and the second projection data after multiple corrections.

[0028] According to embodiments of this disclosure, the third and fourth projection data obtained by scanning at least one reference material specifically include: selecting at least one of the reference materials; scanning the reference materials of different thicknesses using the first type of light source and the second type of light source to obtain the third and fourth projection data; and obtaining the initial mapping relationship based on the third and fourth projection data.

[0029] According to embodiments of this disclosure, the reference material includes at least two types, and the initial mapping relationship between the first type of light source and the second type of light source based on the third projection data and the fourth projection data includes obtaining the initial mapping relationship using a target optimization function, wherein the target optimization function is expressed as:

[0030]

[0031] Where m is the reference material number, h is the material thickness, and K is the voltage value set by the light source during operation. This is the third projection data. For the fourth projection data, R(f) k ) represents the regularization constraint, f k This represents the initial mapping relationship.

[0032] According to embodiments of this disclosure, the reference material includes at least two types, and the initial mapping relationship between the first type of light source and the second type of light source based on the third projection data and the fourth projection data includes obtaining the initial mapping relationship using a target optimization function, wherein the target optimization function is expressed as:

[0033]

[0034] Where m is the reference material number, h is the material thickness, and K is the voltage value set by the light source during operation. This is the third projection data. For the fourth projection data, R(f) k ) represents the regularization constraint, f k This represents the initial mapping relationship.

[0035] According to embodiments of this disclosure, the reference material includes at least two types, and the initial mapping relationship between the first type of light source and the second type of light source based on the third projection data and the fourth projection data includes obtaining the initial mapping relationship using a target optimization function, wherein the target optimization function is expressed as:

[0036]

[0037] Where m is the reference material number, h is the material thickness, and K is the voltage value set by the light source during operation. For the third and fourth projection data, For the target projection data, R(f) k ) represents the regularization constraint, f k This represents the initial mapping relationship.

[0038] According to embodiments of this disclosure, preset iteration stopping conditions include reaching a preset number of iterations or the difference in changes between two reconstructed images reaching a preset threshold.

[0039] According to embodiments of this disclosure, by setting up multiple distributed light sources and dividing them into at least two categories of light sources with different energy levels, the system can selectively configure appropriate energy levels of rays based on the attenuation differences of the scanned object in different directions. This effectively avoids the problems of high-energy redundancy or insufficient low-energy penetration in traditional systems, improving the overall imaging penetration effect and energy efficiency matching capability. Furthermore, since the system uses localized high-energy light sources arranged only in specific high-attenuation directions, rather than uniformly using high-energy rays in all directions, it significantly reduces the overall system's dependence on high-energy light sources while meeting imaging penetration requirements. This helps control energy consumption, reduce radiation dose, and lower light source configuration costs. Attached Figure Description

[0040] The foregoing contents, as well as other objects, features, and advantages of this disclosure, will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0041] Figure 1 This is a schematic diagram of the structure of a X-ray scanning imaging system according to some exemplary embodiments of the present disclosure;

[0042] Figure 2 The schematic diagram illustrates the structure of a static CT imaging system based on a distributed light source according to some exemplary embodiments of the present disclosure;

[0043] Figure 3A This schematically illustrates a static CT imaging system with two types of light sources disposed on different sides according to some exemplary embodiments of the present disclosure;

[0044] Figure 3B This schematically illustrates a static CT imaging system with two types of light sources disposed on different sides according to some other exemplary embodiments of the present disclosure;

[0045] Figure 3C This schematically illustrates a static CT imaging system in which two types of light sources are disposed on the same side according to some exemplary embodiments of the present disclosure;

[0046] Figure 3D This schematically illustrates a static CT imaging system in which two types of light sources are disposed on the same side according to some other exemplary embodiments of the present disclosure;

[0047] Figure 3E The schematic diagram illustrates a static CT imaging system including detector arrangement according to some exemplary embodiments of the present disclosure;

[0048] Figure 3F This schematically illustrates a static CT imaging system in which the endpoints of a target array are aligned with the boundaries of the scanning region according to some exemplary embodiments of the present disclosure;

[0049] Figure 4A A schematic diagram showing the spatial arrangement of a type I light source and a type II light source according to some embodiments of the present disclosure is provided.

[0050] Figure 4B A schematic diagram showing the spatial arrangement of a type I light source and a type II light source according to other embodiments of the present disclosure is shown;

[0051] Figure 5A The schematic diagram illustrates a static CT imaging system including a control module according to some embodiments of the present disclosure;

[0052] Figure 5B The illustration shows a schematic diagram of a distributed light source of some embodiments of the present disclosure arranged on L beam surfaces along the transport path of the scanned object;

[0053] Figure 6 A flowchart illustrating a static CT imaging method according to an embodiment of the present disclosure is shown schematically; and

[0054] Figure 7 A flowchart illustrating a method for data processing in a static CT imaging method according to an embodiment of the present disclosure is shown schematically. Detailed Implementation

[0055] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0056] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0057] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0058] It should be noted that in this article, computed tomography (CT) imaging refers to the process of using X-rays to perform a tomographic scan of the object being scanned, then converting the analog signals received by the detector into digital signals, using a computer to calculate the attenuation coefficient of each pixel, and then reconstructing the image to display the tomographic structure of each part of the scanned object.

[0059] The embodiments of this disclosure will now be described in detail using a CT imaging system for luggage as an example. It should be understood that the embodiments of this disclosure are not limited to CT imaging of luggage; they can be applied to various scanning imaging scenarios. For example, they can be applied to scanning imaging scenarios involving various different objects being examined, including but not limited to vehicle scanning imaging, luggage / parcel scanning imaging, human or animal scanning imaging, organ / tissue scanning imaging, small object scanning imaging, and large object scanning imaging such as containers. It should be noted that the description of scanning imaging scenarios herein is not exhaustive, and the exemplary descriptions below should not be construed as limiting the scope of protection of this disclosure.

[0060] Figure 1 This is a schematic diagram of the structure of a X-ray scanning imaging system according to some exemplary embodiments of the present disclosure. Figure 1 In this diagram, an X-ray scanning-based CT imaging system is schematically illustrated as an example of such an imaging system. Figure 1As shown, the CT imaging system according to this embodiment includes: a gantry 20, a transport mechanism 40, a controller 50, a data processing device 60 (e.g., a computer), a scanning channel 80, etc. The gantry 20 includes a light source 10, such as an X-ray machine, that emits X-rays for examination, and a detection and acquisition device 30. The scanning channel 80 extends along a first direction z and is used to place the object to be scanned 70 during imaging. For example, at least a portion of a support device may be disposed in the scanning channel 80, and the object to be scanned 70 may be placed on the support device. During scanning, the object to be scanned 70 may remain stationary in the imaging area. As another example, at least a portion of the transport mechanism 40 is disposed in the scanning channel 80. The transport mechanism 40 carries the object to be scanned (e.g., luggage to be inspected) 70 through the scanning area between the light source 10 and the detection and acquisition device 30 of the gantry 20. The transport mechanism 40 can move the object to be scanned 70 along the first direction z, while the rays emitted by the light source 10 can pass through the object to be scanned 70 to perform a CT scan. The detection and acquisition device 30 includes, for example, a detector and data acquisition unit with an integrated modular structure, such as a flat panel detector, for detecting X-rays transmitted through the scanned object 70, obtaining analog signals, and converting the analog signals into digital signals to output projection data of the scanned object 70 onto the X-rays. The controller 50 is used to control the synchronous operation of all parts of the entire system. The data processing device 60 is used to process the data acquired by the data acquisition unit, process and reconstruct the data, and output the results.

[0061] like Figure 1 As shown, the light source 10 is placed on one side of the object being scanned 70, and the detection and acquisition device 30 is placed on the other side of the object being scanned 70. The device includes a detector and a data acquisition unit for acquiring transmission data and / or multi-angle projection data of the object being scanned 70. The data acquisition unit includes a data amplification and shaping circuit, which can operate in (current) integration mode or pulse (counting) mode. The data output cable of the detection and acquisition device 30 is connected to the controller 50 and the data processing device 60, and the acquired data is stored in the data processing device 60 according to a trigger command.

[0062] In embodiments of this disclosure, the data processing device 60 may deploy a radiographic imaging module, which includes an image recognition model or a target recognition model. This module can utilize the image recognition model or target recognition model to identify acquired on-site data (e.g., radiographic images). The identification may include target detection, such as detecting target objects or objects of interest in the radiographic images. For example, the target object or object of interest may be various contraband items. It should be understood that the specific category of the target object or object of interest depends on the scanning and imaging site where the radiographic imaging system is deployed; in other words, the specific category of the target object or object of interest is determined by the user of the radiographic imaging system according to specific scanning and imaging needs, and it can be dynamically adjusted as needed.

[0063] In embodiments of this disclosure, the light source 10 may be, for example, an X-ray machine, and the appropriate X-ray target size can be selected according to the imaging resolution. In other embodiments, an X-ray machine may not be used; instead, a linear accelerator or the like may be used to generate the X-ray beam.

[0064] In the embodiments of this disclosure, to adapt to imaging requirements of higher energy or higher throughput, devices capable of generating high-energy X-ray beams, such as linear accelerators (LINACs), can be used as modular distributed light source units. Linear accelerators have a wider energy control range and stronger penetration capabilities, making them suitable for detecting objects such as metals and multilayer composite materials where traditional X-rays significantly attenuate. Introducing them into a distributed structure allows for the construction of hybrid multi-energy imaging systems, achieving broader adaptability for detecting a wider range of object types.

[0065] For example, distributed light sources can support independent control at the module level, and the number and layout of target points can be flexibly configured according to the shape and attenuation characteristics of the actual scanned object, without being limited to ring, rectangle or any asymmetrical arrangement.

[0066] The detection and acquisition device 30 includes an X-ray detector and a data acquisition circuit, etc. The X-ray detector can be a solid-state detector, a gas detector, or other detectors, and the embodiments disclosed herein are not limited thereto. The data acquisition circuit includes a readout circuit, an acquisition trigger circuit, and a data transmission circuit, etc.

[0067] The combination of controller 50 and data processing device 60 includes, for example, a computer device equipped with control and data processing programs, which is responsible for controlling the operation of the CT imaging device, including mechanical rotation, electrical control, safety interlock control, etc., reconstructing CT images from projection data, training image recognition models or target recognition models, and using the trained image recognition models or target recognition models to recognize X-ray scan images, etc.

[0068] In embodiments of this disclosure, the distributed light source includes multiple target points (also known as focal points). For example, multiple X-ray target points can be arranged at high density within a single X-ray tube vacuum chamber. Compared to a traditional single light source, the distributed light source has multiple independent X-ray emission points, which can operate independently and be controlled individually. For example, the distributed light source developed by the applicant in this disclosure can integrate hundreds of X-ray target points within a single X-ray tube, each of which can be independently controlled and quickly switched as needed. For example, the emission of each target point can be precisely controlled, including parameters such as X-ray intensity and emission time, allowing for flexible adjustment of X-ray output based on different scanning locations, object density, and other factors during CT scans, thereby obtaining higher-quality images. For example, the intensity distribution of the X-ray beam can be modulated by controlling the X-ray intensity of different target points to adapt to the imaging requirements of different objects. Furthermore, by employing a multi-target distributed light source, rapid scanning imaging capabilities can be achieved. Due to the presence of multiple X-ray target points, the distributed light source can scan the target object simultaneously or rapidly and sequentially from multiple different locations, greatly improving scanning speed. Compared to traditional CT scans, this method can acquire complete image information of an object in a shorter time, which is significant for scenarios requiring rapid imaging, such as security checks. Furthermore, it enables high-quality imaging results; the collaborative work of multiple target points and precise control allow distributed light sources to provide higher resolution and lower noise images. When imaging complex objects or minute structures, it can more clearly reveal the object's internal structure and details, providing more accurate information.

[0069] Figure 2 The schematic diagram illustrates the structure of a static CT imaging system based on a distributed light source according to some exemplary embodiments of the present disclosure.

[0070] Reference Figure 2 The static CT imaging system 200 may include a light source 220 surrounding the scanning area 210 in a ring-shaped pattern. Specifically, a distributed light source may be configured, with the target points (the outer circles in the figure) of multiple light sources evenly arranged around the periphery of the scanning area 210, forming a light source array surrounding the object being scanned 230. The target points of the light source 220 are arranged along the periphery of the object being scanned, forming a regular and symmetrical dot matrix structure, thereby obtaining relatively consistent ray projections from various angles and supporting multi-angle image acquisition.

[0071] With its wraparound layout, the system can acquire X-ray projections from multiple directions for CT reconstruction. This layout is particularly suitable for fixed security CT systems and industrial non-destructive testing lines, enabling high-throughput scanning that achieves "non-rotational, static imaging" of the inspected object.

[0072] However, in this embodiment, the distributed light source 220 can employ the same type of ray emitting device, and the emitted rays maintain essentially the same energy regardless of its location or orientation. Therefore, when the scanned object has a non-uniform structure or material (e.g., high-density metal or a heavy object in one direction), the rays in all directions have the same energy and cannot effectively penetrate high-attenuation areas, easily resulting in missing image information or severe artifacts in that direction.

[0073] The inventors discovered in their research that the materials of scanned objects often exhibit directional differences. For example, some directions contain high-density or strongly absorbing materials, resulting in significantly higher X-ray attenuation in those directions compared to other directions. In such cases, if all scanning directions use X-rays of the same energy, it can easily lead to problems such as image loss or artifacts due to the inability to penetrate in some directions. On the other hand, increasing the X-ray energy to ensure penetration uniformly leads to energy redundancy in other directions, increasing equipment costs and wasting resources. Therefore, existing static CT imaging systems typically tend to configure high-energy light sources to meet the imaging requirements of the most unfavorable directions, but this "one-size-fits-all" approach is not ideal in terms of energy efficiency and image quality.

[0074] Furthermore, traditional single-energy light sources typically suffer from slow response times when switching between different energy states, making it difficult to meet the demands of efficient and flexible multi-energy imaging and limiting the adaptability of static CT imaging systems in complex testing environments. This limitation is particularly pronounced in static CT imaging systems requiring rapid, multi-angle acquisition.

[0075] Based on this, embodiments of this disclosure provide a static CT imaging system that can strategically deploy high-energy and low-energy X-ray sources according to the differences in attenuation characteristics of the scanned object in different directions. The high-energy X-ray source is used to penetrate high-attenuation directions, while the low-energy X-ray source is used to penetrate low-attenuation directions, thereby achieving precise matching of energy and attenuation. The use of different energy sources not only optimizes X-ray resource allocation, improves image penetration quality and imaging efficiency, but also reduces the overall system's dependence on high-power equipment, exhibiting good energy efficiency, scalability, and the ability to detect complex structures.

[0076] For example, some exemplary embodiments of this disclosure provide a static CT imaging system, including: a scanning channel for conveying an object to be scanned through a scanning area of ​​the static CT imaging system; a plurality of distributed light sources, at least one of the distributed light sources including a plurality of target points configured to emit rays respectively; and a detector for detecting rays emitted from the plurality of distributed light sources and passing through the object to be scanned, wherein the plurality of distributed light sources include at least a first type of light source and a second type of light source, the energy of a first ray emitted by a target point of the first type of light source is higher than the energy of a second ray emitted by a target point of the second type of light source, the first ray passes through the object to be scanned in the scanning area along a first ray path, the second ray passes through the object to be scanned in the scanning area along a second ray path, and the attenuation of the first ray by the object to be scanned along the extension direction of the first ray path is higher than the attenuation of the second ray by the object to be scanned along the extension direction of the second ray path.

[0077] In this embodiment, by setting up multiple distributed light sources and classifying them into at least two different energy levels, the system can selectively configure appropriate energy levels of radiation based on the attenuation differences of the scanned object in different directions. This effectively avoids the problems of high-energy redundancy or insufficient low-energy penetration in traditional systems, improving the overall imaging penetration effect and energy efficiency matching capability. Furthermore, because the system uses localized high-energy light sources arranged only in specific high-attenuation directions, rather than uniformly using high-energy radiation in all directions, it significantly reduces the overall system's dependence on high-energy light sources while meeting imaging penetration requirements. This helps control energy consumption, reduce radiation dose, and lower light source configuration costs.

[0078] The inventors also discovered that in actual imaging processes, the data generated by rays of different energy levels exhibit significant differences in grayscale distribution, noise levels, and attenuation characteristics. If these differences are not addressed specifically, artifacts and distortions can easily occur during image reconstruction, reducing detection accuracy. Furthermore, existing technologies offer limited methods for effectively and in real-time adjusting and matching the light source voltage with the ray attenuation distribution characteristics of the object being detected.

[0079] Based on this, embodiments of this disclosure provide a static CT imaging method applicable to imaging systems equipped with multiple distributed light sources and detectors. The distributed light sources include at least two types of light sources with different energies: a first-type light source emits high-energy rays to penetrate high-attenuation structures, and a second-type light source emits low-energy rays to improve imaging contrast in low-density areas. This method acquires first and second projection data of the high-energy and low-energy rays after they pass through the scanned object, processes the data, and ultimately reconstructs a target image with higher penetration and detail clarity, significantly improving the imaging quality and adaptability of the imaging system in complex structures and multi-material environments.

[0080] For example, the data processing process may include: constructing an initial mapping relationship based on the scanning results of at least one reference material by a type I light source and a type II light source, mapping high-energy projection data to a low-energy response range, and performing initial correction on the first projection data, and then constructing an initial image by combining the second projection data; subsequently, deriving the theoretical attenuation value based on the image, updating the initial mapping relationship, and repeatedly performing correction, reconstruction, and mapping relationship iteration until a preset stopping condition is met, and finally generating a high-precision target reconstruction image by combining the first projection data and the second projection data after multiple corrections.

[0081] In this embodiment, a complete closed-loop mechanism is established based on reference materials to construct multi-energy mapping relationships, infers physical properties from reconstructed images, iteratively corrects high-energy projection data, and fuses low-energy data to reconstruct images. This effectively solves the data inconsistency problem caused by differences in the energy spectrum response between Class I and Class II light sources. This method not only improves the numerical alignment and physical consistency between projection data but also significantly enhances the accuracy and detail restoration capabilities of image reconstruction, reduces artifacts and boundary errors, thereby strengthening the system's versatility, robustness, and engineering application value.

[0082] Figure 3A The schematic diagram illustrates a static CT imaging system with two types of light sources positioned on different sides according to some exemplary embodiments of the present disclosure. Figure 3B The schematic diagram illustrates a static CT imaging system with two types of light sources positioned on different sides according to some other exemplary embodiments of the present disclosure. Figure 3C The schematic diagram illustrates a static CT imaging system in which two types of light sources are disposed on the same side according to some exemplary embodiments of the present disclosure. Figure 3D The schematic diagram illustrates a static CT imaging system in which two types of light sources are disposed on the same side according to some other exemplary embodiments of the present disclosure. Figure 3E The schematic diagram illustrates a static CT imaging system including detector arrangement according to some exemplary embodiments of the present disclosure. Figure 3FThe illustration shows a schematic diagram of a static CT imaging system in which the endpoints of a target array are aligned with the boundaries of a scanning region according to some exemplary embodiments of the present disclosure.

[0083] Reference Figures 3A to 3F In some exemplary embodiments, the static CT imaging system 300 may include a scanning channel 310, a light source 320, and a detector 330.

[0084] The scanning channel 310 is used to transport the object to be scanned 340 through the scanning area 311 of the system. For example, the scanning channel 310 is a linear structure, suitable for scenarios where the object to be scanned 340 passes through in a straight line or conveyor belt manner, such as security checkpoints or industrial production lines. The structure and size of the scanning channel 310 can be adjusted according to the maximum external dimensions of the object to be scanned 340 to ensure effective matching between the imaging area and the object to be scanned.

[0085] The light source 320 may include multiple distributed light sources arranged around the periphery of the scanning channel 310. For example, the multiple distributed light sources may be M distributed light sources, where M is a positive integer greater than or equal to 2.

[0086] The detector receives rays emitted from the light source 320 after penetrating the scanned object 340. The detector can be a linear array or a planar array structure, the specific structure of which can be selected according to application requirements; for example, a planar array detector can be used in security checks. The detector collects intensity data of rays penetrating from different directions and with different energies, which is then transmitted to the image reconstruction module for multi-angle fusion and imaging. (Refer to...) Figure 3E The detector 330 and the light source 320 can be arranged relative to each other in terms of structure.

[0087] Reference Figures 3A to 3F The distributed light source may include multiple target points, arranged in a dot matrix around the periphery of the scanning channel 310. Each target point can be independently excited and emit rays, enabling spatial control and switching of emission. For example, the distributed light source module may include four target points, each capable of being independently excited to emit ray beams to different spatial locations in the scanning area 311, such as... Figures 3A to 3F The 24 target points shown can correspond to 6 distributed light sources. For example, each distributed light source module can include eight target points, each of which can be independently excited to emit beams of light to different spatial locations in the scanning area 311, such as... Figures 3A to 3F The 24 target points shown can be represented by 3 distributed light sources.

[0088] Reference Figures 3A to 3FIn some exemplary embodiments, the distributed light source 320 includes a first-class light source 321 and a second-class light source 322. The first-class light source 321 and the second-class light source 322 can be configured with multiple independently controlled target points. For example, the first-class light source 321 includes N1 target points, and the second-class light source 322 includes N2 target points, where N1 and N2 are both positive integers greater than or equal to 2. Each target point can be individually excited and its voltage independently controlled. The values ​​of N1 and N2 can be optimized according to the size of the scanning area and the required resolution. For example, N1 and N2 can be selected as 4, 8, or more, respectively, to ensure fine and uniform coverage on each side.

[0089] Furthermore, to ensure effective coverage and complete imaging of all sides of the scanning area, the spatial arrangement length of the target array of the first-class and / or second-class light sources must be sufficient to cover the length of any side of the scanning area. That is, the endpoints of the target array should extend beyond or align with the boundary of the scanning area 311 in spatial layout to avoid dead zones or blank areas in the ray projection, thereby ensuring the comprehensive acquisition of the overall structural information of the scanned object.

[0090] Specifically, refer to Figure 3F To ensure the continuity of ray coverage and the integrity of image reconstruction in multiple lateral directions of the scanning area 311, the target arrays of light sources (including a matrix composed of a type 1 light source 321 and / or a type 2 light source 322) arranged on each side must at least cover the boundary length of the scanning area 311 in terms of spatial arrangement length, and preferably should also exceed it appropriately to avoid imaging blind spots. For example, when the height of the left and right sides of the scanning area 311 is H meters and the bottom side length is W meters, the length of the target arrays arranged vertically on the left and right sides should be no less than H, and the length of the target array on the bottom side should be no less than W.

[0091] Reference Figure 3A In a preferred embodiment, several target point units can be added at each end as redundancy to accommodate situations where the structure of the scanned object is offset or its size slightly exceeds the boundary.

[0092] Continue to refer to Figure 3AThe attenuation of the scanned object along the extension direction of the first ray path (e.g., the extension direction of the path containing the first ray L1) may differ from the attenuation of the scanned object along the extension direction of the second ray path (e.g., the extension direction of the path containing the first ray L2). This can be due to various reasons, such as differences in the size and density of the scanned object along different directions, and differences in the degree of attenuation of rays by internal objects. For example, the scanned object may have a larger geometric dimension along the first ray path direction and a smaller dimension along the second ray path direction. For instance, a horizontally placed suitcase may have a horizontal length greater than its vertical height, resulting in a longer horizontal ray path and stronger attenuation. Furthermore, differences in the density distribution of the scanned object along different directions, such as high-density metal, ceramics, or battery packs in one direction and low-density materials like clothing or foam in another, will directly lead to significantly different degrees of attenuation when rays of the same energy penetrate in different directions. For example, the object being scanned may contain multiple locally superimposed structures, cavities, or layers in one direction, resulting in a more complex ray path and greater scattering and absorption in that direction; while in another direction, the structure is more homogeneous and attenuation is less. By spatially optimizing the arrangement of Type I and Type II light sources according to the attenuation characteristics of the object being detected in each direction, the radiation dose and energy loss of the overall system can be significantly reduced while ensuring image integrity.

[0093] According to embodiments of this disclosure, by spatially optimizing the arrangement of Type I light sources 321 and Type II light sources 322 based on the structural characteristics and attenuation paths of the scanned object, the system can achieve multi-dimensional collaborative imaging. For example, if there is a known high attenuation risk in a certain direction, Type I light sources 321 are concentrated in that area to enhance penetration capability; in other directions, Type II light sources 322 are preferentially deployed to improve efficiency and control the overall system energy consumption.

[0094] It should be noted that the embodiments disclosed herein are not limited to only two types of distributed light sources. In practical applications, distributed light sources can be further refined into combinations of three, four, or even more energy levels, depending on the complexity of the specific imaging task. Different types of light sources can use different target structures, different voltage control strategies, or different emission mechanisms (such as a combination of pulsed and continuous emission) to adapt to diverse application scenarios.

[0095] Furthermore, the "Type I light source" and "Type II light source" mentioned in this embodiment are not limited to two device modules with completely different physical structures. In some embodiments, multiple target points in the same light source module can also support high-low voltage switching, thereby forming different types of emission units at the logical level. In addition, this classification is not limited to a fixed layout, and the light source type calibration can be dynamically adjusted through software strategies to achieve reconfiguration capabilities based on task changes.

[0096] The distributed light source arrangement in this embodiment is not limited to a ring, matrix, or symmetrical layout at a specific angle. Non-uniform, asymmetrical, or customized arrangements optimized for specific structures can also be used. For example, in security inspection systems, an energy-enhancing layout with a denser bottom and a sparser top can be used, while in industrial defect detection, a path projection simulation can be performed using a model to pre-configure the optimal energy distribution scheme.

[0097] Reference Figure 3A Viewed along the extension direction of the scanning channel 310, the scanning area 311 can be divided into multiple sides, such as the first side 3111, the second side 3112, and the third side 3113. The first side 3111 and the second side 3112 are arranged adjacent to each other, for example, the left and lower sides of the scanning area 311, respectively, while the first side 3111 and the third side 3113 are arranged opposite each other, for example, the upper and lower sides or the left and right sides are opposite each other.

[0098] Continue to refer to Figure 3A The first side 3111 is provided with a type 1 light source 321, which is used to emit a high-energy first ray L1 to penetrate and collect data in the high attenuation direction of the scanned object; the second side 3112 is provided with a type 2 light source 322, which is used to emit a low-energy second ray L2 to supplement the imaging in the low attenuation area of ​​the scanned object.

[0099] In some exemplary embodiments, a first-type light source 321 and a second-type light source 322 are simultaneously provided on the same side of the scanning region 311. For example, target arrays of different energies can be combined on the same side of the scanning region 311 to form a co-directional multi-energy beam.

[0100] Accordingly, detector 330 can be arranged on multiple sides of the scanning area, specifically including at least two of the first side 3111, the second side 3112, and the third side 3113. For example, detector 330 is disposed on the first side 3111 and the third side 3113, corresponding to opposite positions on the left and right or front and back of the scanning channel, forming a through-beam structure with the distributed light source. For example, detector 330 is disposed on the second side 3112 and the third side 3113, for example, located at the bottom and side of the scanning channel, respectively, suitable for configuration scenarios where the distributed light source emits from the top or oblique side. For example, detector 330 can be disposed on all three sides (see reference). Figure 3E By combining the asymmetric energy configuration of distributed light sources with a multi-path emission strategy, multi-angle and multi-dimensional composite imaging can be achieved.

[0101] In the embodiments of this disclosure, the arrangement of the detectors can be flexibly configured according to the actual light source arrangement, spatial structure, characteristics of the scanned object, and imaging resolution requirements; multiple detector modules can be controlled uniformly or acquired independently, and support on-demand synchronous or asynchronous data transmission and fusion processing. Furthermore, each detector can be configured with different detection sensitivities, resolutions, or dynamic ranges to allow for differentiated design for imaging needs in different directions.

[0102] It should be noted that the terms "first side," "second side," and "third side" in this embodiment are merely examples and are not limited to an absolute physical relationship of up, down, left, and right. The division method can be flexibly defined according to the system installation direction, channel layout, and the entry and exit path of the scanned object. Furthermore, the arrangement of different types of light sources can be interchanged or combined according to task requirements. For example, multiple sides can be equipped with mixed light sources to improve the overall flexibility and energy scheduling capability of the system.

[0103] Reference Figures 3A to 3F The first-class light source 321 and the second-class light source 322 can be flexibly arranged on multiple sides of the scanning area 311 according to the specific shape and structural characteristics of the object being scanned.

[0104] In some exemplary embodiments, a type 1 light source 321 and a type 2 light source 322 can be arranged on different sides of the scanning area 311 to jointly form a semi-enclosed structure surrounding the scanning area 311. Here, the semi-enclosed structure refers to the arrangement of the light sources around the outside of the scanning channel in a partially open manner, forming a not-completely-closed surrounding structure such as a "U-shape" or "C-shape," so that the scanned object can pass smoothly through the scanning channel while simultaneously meeting the requirements for ray projection from multiple directions.

[0105] Reference Figure 3A When the width of the object being scanned is significantly greater than its height (e.g., a flat suitcase or a wide container), the system can primarily deploy a high-energy Class I light source 321 on the opposite sides of the scanning area 311 (e.g., the first side 3111 and the third side 3113) to ensure effective penetration of thicker structures in the horizontal direction; while a lower-energy Class II light source 322 is configured on the bottom side (e.g., the second side 3112) to adapt to relatively thin or low-density areas, thereby avoiding unnecessary high-energy radiation and achieving effective control of radiation dose.

[0106] Reference Figure 3BWhen the height of the object being scanned is greater than its width (e.g., vertically placed packaging or containers), the system can arrange a second type of light source 322 on opposite sides of the scanning area 311 (e.g., the first side 3111 and the third side 3113) to enable efficient penetration of low-energy rays in relatively homogeneous and weakly attenuated areas, while a first type of light source 321 is arranged on the bottom side (e.g., the second side 3112) to provide necessary penetration enhancement for locally existing high-attenuation areas.

[0107] Reference Figure 3C For objects with complex structures or diverse internal components, multiple energy level light sources can be set up simultaneously on the same side (e.g., the first side 3111 or the second side 3112) to form a multi-energy composite beam. This allows for the acquisition of rich penetration information and differential data in a single scan, facilitating subsequent multi-energy spectrum reconstruction, material separation and identification, and advanced data analysis.

[0108] In this embodiment, the second type of light source 322 may include a first second type of sub-light source 3221 and a second second type of sub-light source 3222.

[0109] For example, a primary light source 321 and a first secondary sub-light source 3221 can be jointly disposed on the first side 3111 and the third side 3113; a secondary sub-light source 3222 can be disposed separately on the second side 3112. This arrangement is suitable for situations where the scanned object has both high-density and low-density structural regions mixed on the first side 3111 and the third side 3113, such as horizontally placed equipment or packaging. In this layout, the primary light source 321 can effectively penetrate high-density structures, while the first secondary sub-light source 3221 is used for lateral supplementary radiation, reducing the radiation dose in local areas. The secondary sub-light source 3222 disposed on the second side 3112 is dedicated to providing full coverage of the bottom or other low-density areas, further optimizing overall energy distribution and radiation dose control.

[0110] For example, a primary light source 321 and a first secondary sub-light source 3221 can be jointly disposed on the second side 3112, while a second secondary sub-light source 3222 is disposed on the first side 3111 and the third side 3113. This arrangement is suitable for scanning objects where the bottom or one side has a complex mixture of high and low attenuation regions, such as equipment or packaging containing a high-density base and a lightweight structural body. Through the combined configuration of the primary light source 321 and the first secondary sub-light source 3221 on the second side 3112, targeted energy differential projection in the bottom direction can be achieved to improve the identification capability of structural details in that direction. Simultaneously, the second secondary sub-light source 3222 disposed on the first side 3111 and the third side 3113 can achieve efficient coverage in low-attenuation regions, further reducing unnecessary radiation dose and improving scanning efficiency.

[0111] It should be noted that the embodiments of this disclosure do not limit the arrangement of the light sources to the specific configuration shown in the above schematic diagrams. In practical applications, the distribution positions, quantities, and relative proportions of Class I and Class II light sources can be flexibly adjusted according to the morphological characteristics and attenuation properties of the scanned object. Multiple light sources of different energy levels can also be arranged simultaneously on the same side to achieve more precise spatial energy matching and better imaging performance. Furthermore, for specific task requirements, the spatial layout of high- and low-energy light sources can be combined or dynamically adjusted to further improve the system's applicability and imaging flexibility.

[0112] Figure 4A A schematic diagram showing the spatial arrangement of a type I light source and a type II light source according to some embodiments of the present disclosure is provided. Figure 4B A schematic diagram showing the spatial arrangement of a type I light source and a type II light source according to other embodiments of the present disclosure is shown.

[0113] Combined with reference Figures 4A-4B To achieve a more flexible scanning layout and adapt to a wider range of detection needs, the spatial positions of the Class I light source 321 and the Class II light source 322 can also be arranged in different planes relative to the transport direction of the scanned object.

[0114] Reference Figure 4A The first-class light source 321 and the second-class light source 322 can be jointly arranged in a plane Z1 perpendicular to the conveying direction. That is, all distributed light sources are arranged in a cross-sectional plane perpendicular to the conveying path of the scanned object, thus providing complete projection coverage in its cross-sectional direction as the scanned object passes through the scanning area. This vertical cross-sectional layout is suitable for scenarios requiring rapid static pass-through scanning, such as high-speed conveyor belt inspection devices for baggage and cargo at airports or train stations. It can quickly acquire multi-angle ray projection data in the cross-sectional direction of the scanned object, and improve the recognition ability and penetration performance of complex object structures through the combination of high-energy and low-energy light sources.

[0115] Reference Figure 4BThe first-type light source 321 and the second-type light source 322 can be disposed within multiple parallel planes Z2, Z3...Zn perpendicular to the transport direction of the scanned object, allowing the scanned object to be sequentially irradiated by multiple sets of light sources from different cross-sectional directions as it moves along the transport path. For example, the first-type light source 321 and the second-type light source 322 can be disposed within two parallel planes Z2 and Z3, respectively. The second-type light source on plane Z2 provides low-energy X-ray projection to penetrate relatively thin or low-density areas, while the first-type light source on plane Z3 provides high-energy X-rays to penetrate deeper areas. According to embodiments of this disclosure, as the scanned object passes through the entire scanning area, the system can acquire composite image data at multiple cross-sectional directions and different energy levels, thereby improving the integrity and discrimination capability of the imaging information. This layout is suitable for scenarios with higher imaging quality requirements, such as high-precision foreign object detection and material classification of goods with high-density, multi-layered, or obstructed structures.

[0116] It should be noted that the embodiments of this disclosure do not limit the angles of the first or second plane described above to a fixed value or to the vertical and inclined situations in the examples described above. In practical applications, the angle settings of the scanning plane can be adjusted or optimized according to specific engineering requirements, the type of object being scanned, the transport path, spatial installation constraints, or image reconstruction needs. Furthermore, the combination of one type of light source and two types of light sources is not limited to a single plane; a multi-plane composite configuration can be further adopted to meet more complex and comprehensive detection needs.

[0117] In some exemplary embodiments, the spatial arrangement of the first-type light source 321 and the second-type light source 322 can be further optimized based on the statistical attenuation path data of the scanned object in the target CT imaging scene.

[0118] Specifically, in certain application scenarios, such as airport security, industrial non-destructive testing, and intelligent logistics sorting, scanned objects exhibit relatively stable statistical characteristics in terms of structural morphology, material composition, and typical placement posture. For example, in aviation baggage security checks, baggage items are mostly placed horizontally, with the lower area typically containing high-density footwear or metal utensils, and the upper area containing low-density clothing or plastic packaging; in industrial online inspection, different types of components exhibit a fixed high attenuation direction in their internal core area or edge structure during transport.

[0119] Preferably, based on statistical analysis of a large amount of historical scanning data from the above typical scenarios, an average attenuation path distribution model of the scanned object in various directions can be obtained, thereby forming a probabilistic spatial identification of "high attenuation areas," "low attenuation areas," and "variable areas." On this basis, the system can preferentially arrange first-class light sources (high-energy light sources) in spatial locations where high attenuation paths are statistically more likely to exist, such as below or diagonally; while arranging second-class light sources (low-energy light sources) in directions with high penetration margin and low attenuation risk, such as the top, sides, or back.

[0120] The statistical attenuation path model can be predefined by the manufacturer according to the application scenario before the system leaves the factory, or it can be dynamically updated and optimized during equipment operation by continuously accumulating scan sample data. The system can also be used in conjunction with auxiliary sensing devices (such as contour detectors) and machine learning models to quickly classify and match objects entering the scanning area, thereby loading the corresponding optimal light source layout strategy template to achieve structured adaptive scanning. In some exemplary embodiments, in order to better achieve energy control of the light source and improve the operational stability and penetration efficiency of the system, the voltage configuration strategies of the first-class light source 321 and the second-class light source 322 can adopt different adjustment methods.

[0121] For example, the Class II light source 322 can operate stably using a fixed voltage M2. The fixed voltage M2 can be selected based on the penetration requirements of common low-attenuation structures of the object being scanned, to provide lower but stable penetration capability. A fixed voltage setting can significantly simplify power supply configuration, improve device stability, and reduce system complexity.

[0122] For example, the first-class light source 321 can employ a more flexible voltage configuration. For instance, the operating voltage can be dynamically or statically selected based on a target adjustment range to accommodate different levels of high-attenuation structures or high-density materials that may be encountered during scanning. Specifically, the lower limit of the target adjustment range of the first-class light source 321 can be set to a fixed voltage M2 of the second-class light source 322 to ensure that the first-class light source 321 possesses at least the basic penetration capability of the second-class light source 322 even at the lowest voltage level. The upper limit of the target adjustment range is set to a higher voltage M1 to ensure that the first-class light source 321 can provide high-energy rays significantly higher than the basic level, meeting the effective penetration requirements of areas such as metal parts, thick-walled structures, composite materials, and other high-density regions.

[0123] Preferably, the voltage difference between the upper limit M1 and the lower limit M2 of the target adjustment range is at least greater than or equal to 20kV, for example, 20kV or 40kV. By ensuring a sufficiently wide voltage adjustment range, the system can effectively and accurately configure energy when facing different scanning scenarios and objects being detected, ensuring sufficient penetration capability for high-attenuation structures, while avoiding radiation redundancy and energy waste caused by excessively high voltage in low-attenuation regions.

[0124] Figure 5A The schematic diagram illustrates a static CT imaging system including a control module, according to some embodiments of the present disclosure. Figure 5B The illustration shows a schematic diagram of a distributed light source, according to some embodiments of the present disclosure, arranged on L beam surfaces along the transport path of the scanned object.

[0125] In the embodiments of this disclosure, the voltage adjustment of a type of light source 321 may include various control methods such as manual preset, task-based automatic selection, real-time feedback adjustment, or scanning mode pre-configuration, thereby further enhancing the system's flexibility and adaptability. For example, in a security inspection system, operators can preset different voltage schemes according to the specific type of object being scanned, and the system will execute them automatically; while in industrial online inspection, the voltage of a type of light source can be automatically adjusted in real time based on feedback from front-end sensors to adapt to the inspection needs of different batches or specifications of items on the production line.

[0126] For example, the system includes a control interface for operators to manually set the operating voltage of a type of light source. Based on experience with the properties of the scanned object (e.g., object type, possible structural density, material composition, etc.), operators can manually input voltage values ​​or select preset levels through the control interface or external operating devices to configure the voltage parameters of a type of light source.

[0127] For example, refer to Figure 5A The system includes an auxiliary sensing device and a controller 50. For example, the auxiliary sensing device can be a lidar, infrared detector, structured light module, or stereo vision camera, used to acquire the object's shape contour information (e.g., volume, shape projection, height gradient, etc.) before the object enters the scanning area. Based on the contour information, the controller 50 determines potential high-attenuation regions or abnormal structural distributions on the object and, combined with an empirical model or mapping rules, automatically selects an appropriate operating voltage value for a given type of light source, achieving feedforward dynamic configuration of voltage regulation.

[0128] For example, refer to Figure 5BThe distributed light source can be arranged on L beam surfaces along the transport path of the scanned object, where L is a positive integer representing multiple consecutive projection planes (or viewing positions) set on the scanning path. Each beam surface is equipped with a first-class light source and / or a second-class light source to provide multi-angle, multi-section ray coverage when the scanned object passes through the system. In this embodiment, the operating voltage of the first-class light source on each beam surface can adopt a hierarchical control strategy: the voltage of the first-class light source on the first beam surface (i.e., the front projection plane when the scanned object first enters the system) is fixed at the highest value M1 to ensure the maximum penetration capability of the system to the first visible section; the voltage of the first-class light source on the second to Lth beam surfaces is set according to the ray attenuation degree of the previous beam surface. The system can determine whether the attenuation degree is too high or too low based on the gray value, transmittance change, or reconstructed segment density collected by the detector, and adjust the voltage setting of the next beam surface accordingly to achieve an adaptive adjustment strategy across beam surfaces.

[0129] For example, if the feedback from the first beam surface shows high attenuation, the system will maintain or increase the light source voltage of the second beam surface; if the detection results show that the penetration difficulty is relatively small, the voltage of the second beam surface can be appropriately reduced, thereby reducing the overall energy consumption and heat load of the system while ensuring the image clarity.

[0130] It should be noted that the above control methods can be used individually or in combination as needed. The system can switch between manual setting and automatic adjustment to meet the actual operational requirements of tasks with varying complexity. Furthermore, parameters such as the number of L beam surfaces, their distribution spacing, and the voltage adjustment step strategy are not limited and can be flexibly designed according to the actual size of the object being detected, the transport speed, and the target imaging accuracy.

[0131] In the embodiments of this disclosure, in order to solve the problem of inconsistent projection data caused by different energy levels of radiation, the static CT imaging system also includes a controller for processing and fusing the projection data collected by Class I and Class II light sources to achieve high-quality image reconstruction.

[0132] Figure 6 A flowchart illustrating a static CT imaging method according to an embodiment of the present disclosure is shown schematically.

[0133] like Figure 6 As shown, this static CT imaging method includes operations S610 to S640.

[0134] In operation S610, in response to the first ray passing through the scanned object in the scanning area along the first ray path, first projection data is obtained.

[0135] In operation S620, in response to the second ray passing through the scanned object in the scanning area along the second ray path, second projection data is obtained.

[0136] In operation S630, data processing is performed based on the first projection data and the second projection data.

[0137] In some exemplary embodiments, the data processing based on the first projection data and the second projection data includes: using a mapping relationship to correct the first projection data to obtain corrected first projection data, wherein the mapping relationship is used to map the first projection data to the range where the second projection data is located.

[0138] Figure 7 A flowchart illustrating a method for data processing according to an embodiment of the present disclosure is shown schematically.

[0139] like Figure 7 As shown, the data processing method includes operations S710 to S790.

[0140] In operation S710, third and fourth projection data are obtained by scanning at least one reference material with the first type of light source and the second type of light source under preset energy conditions.

[0141] In operation S720, an initial mapping relationship between the first type of light source and the second type of light source is constructed based on the third projection data and the fourth projection data, wherein the initial mapping relationship is represented as mapping the third projection data to the range of the fourth projection data.

[0142] In the embodiments of this disclosure, a reference material that is common in the target application scenario or structurally representative can be selected, and the reference material can be scanned and tested using both a Class I light source and a Class II light source. To ensure the breadth and accuracy of the modeling, the reference material is prepared into test samples of different thicknesses h during the experiment, and it is scanned one by one using a Class I light source at multiple representative voltage settings K (K belongs to the target adjustment range), while the scanning results of the Class II light source at a fixed voltage M2 are simultaneously acquired.

[0143] Through the above experimental process, the system can obtain third and fourth projection data of Class I and Class II light sources under different thickness and voltage combinations, respectively, and establish the projection value of Class I light source. Projection values ​​of type II light sources The functional mapping relationship between them. This mapping relationship can be expressed as:

[0144] (1)

[0145] function f kThis is the initial energy response mapping relationship used by the system for subsequent data correction. Essentially, it converts the projection data collected by a type of light source under arbitrary thickness h and voltage K into a data representation that is aligned with the response results of a type of light source in the numerical domain, thereby providing a unified reference benchmark for subsequent multi-energy data fusion and image reconstruction.

[0146] In other embodiments, the initial mapping relationship can also be expressed as mapping the fourth projection data to the range of the third projection data. Similarly, a reference material can be selected, keeping the voltage conditions of the two types of light sources adjustable while fixing the voltage setting K1 of the first type of light source, and performing a system scan on test samples of different thicknesses h. Thus, the system can establish the projection values ​​of the first type of light source. Projection values ​​of type II light sources The functional mapping relationship between them. This mapping relationship can be expressed as:

[0147] (2)

[0148] In other embodiments, the initial mapping relationship is represented as mapping the fourth and third projection data to the range of the pre-acquired target projection data. Similarly, the system can obtain raw projection data from scanning the same reference material using Class I and Class II light sources under different imaging parameters. By comparing with known target projection data Comparative analysis was conducted to construct a general normalized mapping mechanism. Target projection data can originate from standard high-precision imaging equipment or from high-reliability reference image data generated by combining multi-mode data fusion and inversion algorithms. This mapping relationship can be expressed as:

[0149] (3)

[0150] Preferably, the reference materials include at least two or more types, and differ in density, atomic number, attenuation coefficient, etc., to cover the typical physical properties of common objects in the target application of the system (e.g., metallic materials, polymeric materials, and organic materials). Each reference material can be prepared into several samples of different thicknesses, and scanned under a multi-voltage setting K of a type one light source and a fixed voltage M2 of a type two light source to obtain its corresponding third projection data and fourth projection data.

[0151] To construct a more generalizable initial mapping relationship, the system no longer directly uses single material data to establish a simple function, but instead introduces an objective optimization function for mapping modeling. This optimization objective can be expressed as:

[0152] (4)

[0153] Where m is the reference material number, R(f)k ) can be used as a regularization constraint. For example, the L2 norm can be selected to ensure smoothness, or Total Variation can be selected to enhance the stability and noise resistance of the model.

[0154] Similarly, in embodiments where the initial mapping relationship can also be expressed as mapping the fourth projection data to the range of the third projection data, the optimization objective can be expressed as:

[0155] (5)

[0156] Similarly, in an embodiment where the initial mapping relationship is represented as mapping the fourth and third projection data to the range of the pre-acquired target projection data, the optimization objective can be expressed as:

[0157] (6)

[0158] By solving the above objective function, an initial mapping relationship that takes into account the attenuation characteristics of multiple materials can be obtained, which is significantly better than the simple fitting model under a single material and can more effectively deal with the situation of complex structure and diverse materials of actual scanned objects.

[0159] In operation S730, the first projection data is initially corrected based on the initial mapping relationship to obtain the first projection data after initial correction. That is, the first projection data can be mapped to the data domain of the second type of light source according to the statistical energy response through the function of the initial mapping relationship, eliminating the intensity drift and grayscale deviation caused by the difference in energy spectrum, thereby obtaining the first projection data after initial correction.

[0160] Similarly, in embodiments where the initial mapping relationship can also be expressed as mapping the fourth projection data to the range of the third projection data, the second projection data can be initially corrected based on the initial mapping relationship to obtain the second projection data after initial correction.

[0161] Similarly, in an embodiment where the initial mapping relationship is represented as mapping the fourth and third projection data to the range of the pre-acquired target projection data, the first and second projection data can be initially corrected based on the initial mapping relationship to obtain the first and second projection data after initial correction.

[0162] In operation S740, an initial reconstructed image is constructed based on the first projection data and the second projection data after initial correction.

[0163] Similarly, in embodiments where the initial mapping relationship can also be represented as mapping the fourth projection data to the range of the third projection data, an initial reconstructed image can be constructed based on the second projection data and the first projection data after initial correction.

[0164] Similarly, in an embodiment where the initial mapping relationship is represented as mapping the fourth and third projection data to the range of the pre-acquired target projection data, an initial reconstructed image can be constructed based on the initially corrected second projection data and the initially corrected first projection data.

[0165] For example, an initial image can be constructed based on filtered back projection (FBP), algebraic reconstruction techniques (ART, SART), or statistical iterative reconstruction methods (SIR, MLEM). The specific reconstruction algorithm can be flexibly configured according to the density of the acquisition path, reconstruction efficiency requirements, and image resolution target.

[0166] The initial reconstructed image serves as a crucial data foundation for constructing theoretical attenuation paths and optimizing mapping relationships in subsequent steps. By analyzing the spatial distribution and density estimation of voxels in the image, the physical property parameters along each ray path can be further deduced, which can then be used to execute subsequent theoretical modeling and error correction iterative processes.

[0167] It should be noted that the initial reconstructed image is used as an intermediate result, and its grayscale value may not directly correspond to the true linear attenuation coefficient or material density. Further improvements in imaging consistency and physical accuracy are still needed through multiple rounds of correction in subsequent steps.

[0168] In operation S750, a theoretical attenuation value is calculated based on the initial reconstructed image, and the initial mapping relationship is updated based on the theoretical attenuation value to obtain the updated mapping relationship.

[0169] After the initial image reconstruction was completed, an initial reconstructed image reflecting the density distribution and structural composition of the scanned object was obtained. Although the initial reconstructed image was generated based on the fused projection data, there was still a certain energy response bias because the initial mapping relationship was only derived from the reference material or statistical fitting. The projection residuals were particularly significant in multi-material and multi-density regions.

[0170] To this end, we can first use the gray values ​​of each voxel position in the initial reconstructed image, combined with a pre-set material library, density / attenuation coefficient mapping table, or material classification results based on image segmentation, to assign possible physical property parameters to each position r in the reconstructed image, including: material type (such as metal, organic matter, polymer, etc.), density or effective atomic number, and linear attenuation coefficient under the corresponding energy spectrum.

[0171] Next, for each ray trajectory L, based on the material property model reconstructed from the aforementioned image, the following energy integral modeling process can be performed to calculate the theoretical attenuation values ​​corresponding to type I and type II light sources:

[0172] (7)

[0173] in, Optical energy spectrum, The detector response energy spectrum, Let be the linear attenuation coefficient of the material at position r for the ray at energy E, dl represent the integral over the ray path, and dE represent the integral over energy. Using the energy spectrum of energy K and M2, the theoretical attenuation values ​​along the ray path of a certain type of light source are calculated according to the above formula. and .use , Establish a new mapping relationship with the method in S1 .

[0174] Through the above integration, the system can derive the ideal attenuation performance of each path under theoretical conditions and compare it with the actual values ​​in the original projection data. The difference reflects the degree of deviation of the original mapping relationship under the current physical conditions and can be used to guide the next round of mapping function updates.

[0175] For example, the update strategy can be implemented as follows: based on residual minimization regression, adjust the mapping function parameters to make its output value closer to the current theoretical decay; introduce a weighted correction factor to multiply the initial mapping output by a path-related scaling factor or offset term; and optimize the new mapping by minimizing the objective function.

[0176] In operation S760, the corrected first projection data is re-corrected based on the updated mapping relationship to obtain the re-corrected first projection data. The re-correction is based on a mapping function that is more realistic and closer to the actual physical attenuation behavior, effectively compensating for the previous differences in energy response and path response errors, making the data more numerically aligned.

[0177] Similarly, in embodiments where the initial mapping relationship can also be represented as mapping the fourth projection data to the range of the third projection data, the second projection data after the initial correction can be corrected again based on the updated mapping relationship to obtain the second projection data after the second correction.

[0178] Similarly, in an embodiment where the initial mapping relationship is represented as mapping the fourth and third projection data to the range of the pre-acquired target projection data, the first and second projection data after the initial correction can be corrected again based on the updated mapping relationship to obtain the first and second projection data after the second correction.

[0179] When operating S770, determine whether the preset iteration stop condition has been met.

[0180] During operation S780, the process of reconstructing the image, updating the mapping relationship, and correcting the first projection data are repeated until the preset iteration stop condition is reached, and the first projection data after multiple corrections is obtained.

[0181] In other words, each iteration includes: using the current correction result and the data from the second type of light source to reconstruct the image and generate an updated image result; calculating the theoretical attenuation value based on the new image and re-evaluating the accuracy of the current mapping relationship; if the preset iteration stopping condition is not met, the mapping function is further optimized and used for the next round of correction to obtain updated projection data.

[0182] In some exemplary embodiments, the iteration stopping condition may be: the structural similarity (SSIM) of the corrected image reaches stability; the number of iteration rounds reaches the upper limit (e.g., 5 rounds, 10 rounds); the change of the mapping function between two consecutive iterations is less than a threshold; the residual of the projected data is less than the minimum tolerance error, etc.

[0183] Similarly, in embodiments where the initial mapping relationship can also be represented as mapping the fourth projection data to the range of the third projection data, the process of constructing the reconstructed image, updating the mapping relationship, and correcting the second projection data can be repeated until a preset iteration stop condition is reached, thereby obtaining the second projection data after multiple corrections.

[0184] Similarly, in an embodiment where the initial mapping relationship is represented as mapping the fourth and third projection data to the range of the pre-acquired target projection data, the process of constructing the reconstructed image, updating the mapping relationship, and correcting the first and second projection data can be repeated until a preset iteration stop condition is reached, thereby obtaining the first and second projection data after multiple corrections.

[0185] Return to reference Figure 6 In operation S640, image reconstruction is performed based on the processed projection data to obtain the target reconstructed image.

[0186] For example, in operation S790, a target reconstruction image is constructed based on the first projection data and the second projection data after multiple corrections. This image integrates the penetrating power of high-energy rays with the structural details of low-energy rays, and through multiple rounds of mapping updates and data corrections, it effectively reduces artifacts, density deviations, and boundary blurring problems, thus possessing higher imaging reliability and analytical value.

[0187] Similarly, in embodiments where the initial mapping relationship can also be represented as mapping the fourth projection data to the range of the third projection data, the target reconstructed image can be constructed based on the second projection data and the first projection data after multiple corrections.

[0188] Similarly, in an embodiment where the initial mapping relationship is represented as mapping the fourth and third projection data to the range of the pre-acquired target projection data, the target reconstructed image can be constructed based on the first and second projection data after multiple corrections. It should be noted that the above iterative process can be integrated into the image reconstruction engine, supporting parallel accelerated computation, data caching optimization, and intermediate state monitoring. The iterative adjustment of the mapping function can also be based on different forms such as analytical functions, interpolation functions, deep learning models, or empirical lookup tables, exhibiting high adaptability and scalability.

[0189] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A static CT imaging system, characterized in that, include: A scanning channel, which is used to transport the object being scanned through the scanning area of ​​the static CT imaging system; Multiple distributed light sources, at least one of the distributed light sources comprising multiple target points, the multiple target points being configured to emit rays respectively; as well as A detector, the detector being used to detect rays emitted from the plurality of said distributed light sources and passing through the scanned object, The distributed light sources include at least one type of light source and two types of light sources. The energy of the first ray emitted from the target point of the first type of light source is higher than the energy of the second ray emitted from the target point of the second type of light source. The first ray passes through the object being scanned in the scanning area along the first ray path, and the second ray passes through the object being scanned in the scanning area along the second ray path. The attenuation of the first ray by the object being scanned along the extension direction of the first ray path is higher than the attenuation of the second ray by the object being scanned along the extension direction of the second ray path. The first type of light source and the second type of light source are arranged on at least one side of the scanning area based on the statistical attenuation path of the scanned object in the target CT imaging scene. The statistical attenuation path is determined based on statistical analysis of historical scanning data in the target CT imaging scene. The statistical analysis is used to obtain the average attenuation path distribution of the scanned object in each direction. The first type of light source is arranged corresponding to the high attenuation direction in the statistical attenuation path, and the second type of light source is arranged corresponding to the low attenuation direction in the statistical attenuation path.

2. The system according to claim 1, characterized in that, The statistical attenuation path is characterized by a statistical attenuation path model, which is dynamically updated during device operation by accumulating scan sample data from the target CT imaging scene.

3. The system according to claim 1 or 2, characterized in that, Viewed along the extension direction of the scanning channel, the scanning area includes at least a first side, a second side, and a third side. The first side and the second side are arranged adjacent to each other, and the first side and the third side are arranged opposite to each other. The second side is provided with one of the first type of light source and the second type of light source, and at least one of the first side and the third side is provided with the other of the first type of light source and the second type of light source.

4. The system according to claim 1 or 2, characterized in that, Viewed along the extension direction of the scanning channel, the scanning area includes at least a first side, a second side, and a third side. The first side and the second side are arranged adjacent to each other, and the first side and the third side are arranged opposite to each other. The first type of light source and the second type of light source are provided on the same side of the scanning area.

5. The system according to claim 4, characterized in that, The light source combination, including the first type of light source and the second type of light source, is arranged on the first side, the second side and the third side to form a semi-enclosed structure surrounding the scanning area.

6. The system according to claim 5, characterized in that, The first type of light source is disposed on the first side and the third side, and the second type of light source is disposed on the second side; or The two types of light sources are disposed on the first side and the third side, and the one type of light source is disposed on the second side.

7. The system according to claim 5, characterized in that, The two types of light sources include a first type of sub-light source and a second type of sub-light source. The first type of light source and the first and second type of sub-light sources are disposed on the first side and the third side, and the second type of sub-light source is disposed on the second side; or The two types of light sources include a first type of sub-light source and a second type of sub-light source. The first type of light source and the first type of sub-light source are disposed on the second side, and the second type of sub-light source is disposed on the first side and the third side.

8. The system according to any one of claims 1 to 2, 5 to 7, characterized in that, The first type of light source and the second type of light source are arranged in a plane perpendicular to the transport direction of the scanned object; or The first type of light source and the second type of light source are arranged in multiple parallel planes perpendicular to the transport direction of the scanned object.

9. The system according to any one of claims 1 to 2, 5 to 7, characterized in that, The operating voltage of the second type of light source is a fixed voltage M2, while the operating voltage of the first type of light source is selected based on the target adjustment range.

10. The system according to claim 9, characterized in that, The lower limit of the target adjustment range is M2, the upper limit of the target adjustment range is M1, and the difference between M1 and M2 is greater than or equal to 20kV.

11. The system according to any one of claims 1 to 2, 5 to 7, characterized in that, The first type of light source includes N1 target points, and the second type of light source includes N2 target points, where N1 and N2 are both positive integers greater than or equal to 2.

12. The system according to claim 11, characterized in that, When viewed along the extension direction of the scanning channel, the length of the target points in the first type of light source and / or the second type of light source at least covers the length on either side of the scanning area.

13. The system according to claim 10, characterized in that, The static CT imaging system also includes a control interface, which is used by the operator to set the operating voltage of the light source according to the properties of the object being scanned.

14. The system according to claim 10, characterized in that, The static CT imaging system also includes an auxiliary sensing device and a controller, wherein the controller sets the operating voltage of the first type of light source based on the contour information of the scanned object obtained by the auxiliary sensing device.

15. The system according to claim 10, characterized in that, The distributed light source is distributed on L beam surfaces along the transport path of the scanned object, where L is a positive integer greater than or equal to 2. The operating voltage of the distributed light source on the first beam surface is set to M1, and the operating voltage of the distributed light source on the second to L beam surfaces is set according to the ray attenuation degree corresponding to the previous beam surface.

16. The system according to any one of claims 1-2, 5-7, and 10, characterized in that, The static CT imaging system further includes a controller configured to: perform correction processing on the first projection data obtained by scanning with the first type of light source, and perform image reconstruction based on the corrected first projection data and the second projection data obtained by scanning with the second type of light source, so as to obtain a target reconstructed image.

17. The system according to any one of claims 5 to 7, characterized in that, The detectors are arranged on at least two of the first side, the second side, and the third side.

18. A static CT imaging method, wherein, The static CT imaging method is used in a static CT imaging system, which includes a scanning area, multiple distributed light sources, and detectors. The multiple distributed light sources include at least a first-class light source and a second-class light source. The first-class and second-class light sources are arranged on at least one side of the scanning area based on the statistical attenuation path of the scanned object in the target CT imaging scene. The statistical attenuation path is determined based on statistical analysis of historical scanning data in the target CT imaging scene. The statistical analysis is used to obtain the average attenuation path distribution of the scanned object in various directions. The first-class light source is arranged corresponding to the high attenuation direction in the statistical attenuation path, and the second-class light source is arranged corresponding to the low attenuation direction in the statistical attenuation path. The energy of the first ray emitted from the target point of the first-class light source is higher than the energy of the second ray emitted from the target point of the second-class light source. The static CT imaging method is characterized by comprising: In response to the first ray passing through the object being scanned in the scanning area along the first ray path, first projection data is obtained; In response to the second ray passing through the scanned object in the scanning area along the second ray path, second projection data is obtained; Data processing is performed based on the first projection data and the second projection data; and Image reconstruction is performed based on the processed projection data to obtain the reconstructed image of the target. The data processing based on the first projection data and the second projection data includes: using a mapping relationship to correct at least one of the first projection data and the second projection data to obtain corrected first projection data and / or corrected second projection data. The mapping relationship is used to: map the first projection data to the range where the second projection data is located, map the second projection data to the range where the first projection data is located, or map the first projection data and the second projection data to the range where a pre-acquired third projection data is located.

19. The method according to claim 18, characterized in that, The data processing based on the first projection data and the second projection data specifically includes: Acquire third and fourth projection data by scanning at least one reference material with the first type of light source and the second type of light source under preset energy conditions; An initial mapping relationship between the first type of light source and the second type of light source is constructed based on the third projection data and the fourth projection data, wherein the initial mapping relationship is represented as mapping the third projection data to the range of the fourth projection data; The first projection data is initially corrected based on the initial mapping relationship to obtain the first projection data after initial correction. An initial reconstructed image is constructed based on the first and second projection data after initial correction. The theoretical attenuation value is calculated based on the initial reconstructed image, and the initial mapping relationship is updated based on the theoretical attenuation value to obtain the updated mapping relationship; Based on the updated mapping relationship, the first projection data after the initial correction is corrected again to obtain the second-corrected first projection data; and The process of reconstructing the image, updating the mapping relationship, and correcting the first projection data is repeated until the preset iteration stop condition is met, and the first projection data after multiple corrections is obtained.

20. The method according to claim 19, characterized in that, The process of image reconstruction based on the processed projection data to obtain the target reconstructed image specifically includes: A target reconstruction image is constructed based on the first projection data and the second projection data after multiple corrections.

21. The method according to claim 18, characterized in that, The data processing based on the first projection data and the second projection data specifically includes: Acquire third and fourth projection data by scanning at least one reference material with the first type of light source and the second type of light source under preset energy conditions; An initial mapping relationship between the first type of light source and the second type of light source is constructed based on the third projection data and the fourth projection data, wherein the initial mapping relationship means mapping the fourth projection data to the range of the third projection data; The second projection data is initially corrected based on the initial mapping relationship to obtain the second projection data after initial correction. An initial reconstructed image is constructed based on the second projection data after initial correction and the first projection data; The theoretical attenuation value is calculated based on the initial reconstructed image, and the initial mapping relationship is updated based on the theoretical attenuation value to obtain the updated mapping relationship; Based on the updated mapping relationship, the initially corrected second projection data is corrected again to obtain the second projection data after further correction; and The process of reconstructing the image, updating the mapping relationship, and correcting the second projection data is repeated until the preset iteration stop condition is met, and the second projection data after multiple corrections is obtained.

22. The method according to claim 21, characterized in that, The process of image reconstruction based on the processed projection data to obtain the target reconstructed image specifically includes: A target reconstruction image is constructed based on the second projection data after multiple corrections and the first projection data.

23. The method according to claim 18, characterized in that, The data processing based on the first projection data and the second projection data specifically includes: Acquire third and fourth projection data by scanning at least one reference material with the first type of light source and the second type of light source under preset energy conditions; Based on the third projection data and the fourth projection data, an initial mapping relationship is constructed between the first type of light source and the second type of light source, wherein the initial mapping relationship means mapping the fourth projection data and the third projection data to the range of the pre-acquired target projection data; Based on the initial mapping relationship, the first projection data and the second projection data are initially corrected to obtain the first projection data and the second projection data after initial correction. An initial reconstructed image is constructed based on the second projection data after initial correction and the first projection data after initial correction; The theoretical attenuation value is calculated based on the initial reconstructed image, and the initial mapping relationship is updated based on the theoretical attenuation value to obtain the updated mapping relationship; Based on the updated mapping relationship, the initially corrected first projection data and the initially corrected second projection data are corrected again to obtain the second corrected first projection data and the second corrected second projection data; and The process of reconstructing the image, updating the mapping relationship, and correcting the first and second projection data is repeated until the preset iteration stop condition is met, resulting in the first and second projection data after multiple corrections.

24. The method according to claim 23, characterized in that, The process of image reconstruction based on the processed projection data to obtain the target reconstructed image specifically includes: The target reconstruction image is constructed based on the first projection data after multiple corrections and the second projection data after multiple corrections.

25. The method according to claim 19, 21, or 23, characterized in that, The third and fourth projection data obtained by scanning at least one reference material specifically include: Select at least one of the aforementioned reference materials; By scanning the reference material of different thicknesses using the first type of light source and the second type of light source, the third projection data and the fourth projection data are obtained; and The initial mapping relationship is obtained based on the third projection data and the fourth projection data.

26. The method according to claim 19, characterized in that, The reference materials include at least two types. Constructing the initial mapping relationship between the first-type light source and the second-type light source based on the third projection data and the fourth projection data includes obtaining the initial mapping relationship using a target optimization function, which is expressed as: Where m is the reference material number, h is the material thickness, and K is the voltage value set by the light source during operation. This is the third projection data. For the fourth projection data, R(f) k ) represents the regularization constraint, f k This represents the initial mapping relationship.

27. The method according to claim 21, characterized in that, The reference materials include at least two types. Constructing the initial mapping relationship between the first-type light source and the second-type light source based on the third projection data and the fourth projection data includes obtaining the initial mapping relationship using a target optimization function, which is expressed as: Where m is the reference material number, h is the material thickness, and K is the voltage value set by the light source during operation. This is the third projection data. For the fourth projection data, R(f) k ) represents the regularization constraint, f k This represents the initial mapping relationship.

28. The method according to claim 23, characterized in that, The reference materials include at least two types. Constructing the initial mapping relationship between the first-type light source and the second-type light source based on the third projection data and the fourth projection data includes obtaining the initial mapping relationship using a target optimization function, which is expressed as: Where m is the reference material number, h is the material thickness, and K is the voltage value set by the light source during operation. For the third and fourth projection data, For the target projection data, R(f) k ) represents the regularization constraint, f k This represents the initial mapping relationship.

29. The method according to any one of claims 19-24 and 26-28, characterized in that, The preset iteration stopping conditions include reaching a preset number of iterations or the difference in changes between two reconstructed images reaching a preset threshold.

Images