CT imaging system and method based on distributed small micro-focus X-ray source

Abstract

This invention relates to the field of computed tomography (CT) technology, and particularly to a CT imaging system and method based on a distributed microfocus X-ray source. The system includes a distributed X-ray source with multiple microfocuses, a detector, a scanning carrier, a control module, and a data processing module. During scanning, the distributed X-ray source and detector simultaneously rotate around a center of rotation relative to the object being scanned. Multiple microfocuses emit beams sequentially according to a beam-emission strategy to disperse heat dissipation, effectively increasing the peak power of the microfocus X-ray source and reducing the time required for a single CT scan. Furthermore, by designing the beam-emission strategy of the distributed X-ray source, the sampling distribution of multiple microfocuses can be optimized, achieving sub-pixel-level image reconstruction and further improving spatial resolution. Therefore, this system and method can achieve ultrafast high-definition CT imaging, solving the problem that traditional single-focus X-ray CT systems struggle to achieve both high spatial and temporal resolution.

Description

Technical Field

[0001] This invention relates to the field of computed tomography (CT) technology, and in particular to a CT imaging system and method based on a distributed microfocus X-ray source. Background Technology

[0002] Computed tomography (CT) is a commonly used non-destructive testing technique that can obtain information about the internal structure of the object being tested without damaging it. It is currently widely used in medical imaging, industrial diagnostics, and security inspection.

[0003] X-ray source focal spot size and power are two important factors affecting the overall performance of a CT system. The focal spot size affects the system's spatial resolution: the larger the focal spot size, the lower the spatial resolution of the image and the blurrier the image. The power limits the imaging speed: the higher the power, the more X-ray photons are irradiated onto the sample per unit time, and the shorter the exposure time required and the faster the imaging speed, given a specified signal-to-noise ratio.

[0004] However, there is an antagonistic relationship between focal spot size and X-ray source power. Common X-ray sources generate X-rays by bombarding an anode target with electrons to produce bremsstrahlung radiation, a process that generates a significant amount of heat. If the power per unit area on the target material is too high, the target surface will gradually melt over prolonged operation. A smaller X-ray source focal spot can provide higher spatial resolution, but at the cost of reduced permissible source power and a significantly longer time to acquire projection data with acceptable noise levels. Therefore, monofocal X-ray CT systems struggle to simultaneously achieve both high spatial and temporal resolution. Summary of the Invention

[0005] This invention provides a CT imaging system and method based on a distributed micro-focus X-ray source to solve the problem that traditional monofocal X-ray CT systems cannot simultaneously achieve high spatial resolution and high temporal resolution.

[0006] A first aspect of this invention provides a CT imaging system based on a distributed microfocal X-ray source, comprising: a distributed X-ray source, a scanning carrier, a detector, a data processing module, and a control module. The distributed X-ray source has multiple microfocals, and the focal line array is parallel to the tomographic imaging plane for emitting X-rays. The scanning carrier is used to translate the object to be detected to the target scanning area. The detector is used to detect X-ray signals entering the target scanning area. The data processing module is used to acquire multifocal projection data generated by the X-ray signals and perform image reconstruction processing on the multifocal projection data to obtain a reconstructed image. The control module is used to control the beam output of the distributed X-ray source according to a beam output strategy and to control the detector to acquire data from the X-ray signals.

[0007] During the scanning process, the distributed X-ray source rotates around the rotation center relative to the object to be detected. The multiple microfocal points sequentially emit beams toward the object to be detected according to the beam emission strategy. The detector collects the X-ray signals. The data processing module collects the multifocal projection data generated by the X-ray signals and performs subpixel-level image reconstruction based on the multifocal projection data to obtain the reconstructed image.

[0008] Optionally, during the scanning process, the control module controls the data acquisition of the detector to be synchronized with the microfocus switching of the distributed X-ray source, and the detector reads the X-ray signal from a microfocus in each frame.

[0009] Optionally, the beam emission strategy is determined based on preset high-resolution sampling conditions, wherein the beam emission strategy includes: the beam emission time, beam emission interval, number of switching between focal points, motion trajectory, and rotation rate of the distributed X-ray source and the detector relative to the object to be detected.

[0010] Optionally, the motion trajectory includes a linear-like circular trajectory or a spiral-like trajectory.

[0011] Optionally, the expression for the preset high-resolution sampling condition is:

[0012]

[0013] in, and Let be the index of any two foci, and < , and Each is a focal point and focus Relative to the position of the center of the X-ray source array, Focus and focus The misalignment distance of the detector direction during high-resolution sampling. The angle sampling interval is... Let be any integer, representing the number of angular offsets between the two foci, and N be the number of foci. and These represent the distance from the distributed X-ray source to the rotation center and the distance from the distributed X-ray source to the detector, respectively.

[0014] Optionally, the data processing module includes:

[0015] The projection data for each focal point is independently analyzed and reconstructed to obtain multiple reconstructed sub-images, and these multiple reconstructed sub-images are then fused to obtain the reconstructed image; or

[0016] The multifocal projection data is rearranged and interpolated to obtain rearranged high-resolution projection data, and the rearranged high-resolution projection data is then analyzed and reconstructed to obtain the reconstructed image; or

[0017] The reconstructed image is obtained by iteratively reconstructing the multifocal projection data.

[0018] A second aspect of the present invention provides a CT imaging method based on a distributed small-focus X-ray source, comprising the following steps: generating a beam-out strategy according to preset high-resolution sampling conditions, and setting the beam-out strategy for a control module; using the control module to translate the object to be detected to the target scanning area, and controlling the distributed X-ray source to emit beams to the object to be detected and the detector to synchronously acquire multifocal projection data; and using a data processing module to perform image reconstruction processing on the multifocal projection data to obtain a reconstructed image.

[0019] A third aspect of the present invention provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the CT imaging method based on a distributed small-focus X-ray source as described in the above embodiments.

[0020] A fourth aspect of the present invention provides a computer program product, which, when executed by a processor, implements the above-described CT imaging method based on a distributed small-focus X-ray source.

[0021] A fifth aspect of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described CT imaging method based on a distributed small-focus X-ray source.

[0022] The CT imaging system and method based on a distributed micro-focus X-ray source proposed in this invention employs a distributed X-ray source and retains the rotational scanning mode of the third-generation CT system, simultaneously possessing advantages such as micro-focus, high power, and high spatial resolution. During the scanning process, the focal points at different locations do not need to continuously emit beams; instead, multiple focal points are emitted sequentially, which significantly reduces the duty cycle of each focal pulse, thereby significantly increasing the peak power of the micro-focus X-ray source, improving the scanning speed of micro-focus CT, and maintaining imaging spatial resolution and signal-to-noise ratio. By rationally designing system parameters and beam emission strategies, the sampling distribution of multiple focal points can be optimized, thereby achieving sub-pixel-level image reconstruction and further improving spatial resolution.

[0023] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0025] Figure 1 A schematic diagram of the structure of a CT imaging system based on a distributed small-focus X-ray source according to an embodiment of the present invention;

[0026] Figure 2 The following are schematic diagrams of various scanning trajectories provided according to embodiments of the present invention, wherein (a) is a circular sequential beam exit, (b) is a circular folded beam exit, (c) is a spiral sequential beam exit, and (d) is a spiral instantaneous folded beam exit;

[0027] Figure 3 This is a schematic diagram illustrating parameter optimization for a preset optimization target provided in an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram comparing the projection sampling of multi-source CT and conventional single-source CT according to an embodiment of the present invention, wherein (a) is the projection sampling of conventional single-source CT and (b) is the projection sampling of multi-source CT.

[0029] Figure 5 A sampling schematic diagram of a CT imaging system based on a distributed microfocal X-ray source according to an embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram illustrating the signal-to-noise ratio improvement of a CT imaging system based on a distributed micro-focus X-ray source according to an embodiment of the present invention, wherein (a) is a three-focus beam output, (b) is a two-focus beam output, and (c) is a single-focus beam output;

[0031] Figure 7 This is a schematic diagram of a high-resolution reconstructed image under the beam-out strategy provided in an embodiment of the present invention, wherein (a) is a trifocal beam-out reconstruction, (b) is a monofocal beam-out reconstruction, and (c) is a spatial resolution comparison diagram of monofocal beam-out reconstruction and trifocal beam-out reconstruction;

[0032] Figure 8 A flowchart illustrating a CT imaging method based on a distributed small-focus X-ray source according to an embodiment of the present invention;

[0033] Figure 9This is a schematic diagram of the structure of an electronic device provided according to an embodiment of the present invention.

[0034] Explanation of reference numerals in the attached figures:

[0035] 100 - Distributed X-ray source, 200 - Scanning carrier, 300 - Detector, 400 - Data processing module, and 500 - Control module. Detailed Implementation

[0036] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0037] The following description, with reference to the accompanying drawings, describes a CT imaging system and method based on a distributed small-focus X-ray source according to embodiments of the present invention.

[0038] Figure 1 This is a schematic diagram of a CT imaging system based on a distributed micro-focus X-ray source, provided as an embodiment of the present invention.

[0039] like Figure 1 As shown, the CT imaging system based on a distributed micro-focus X-ray source includes: a distributed X-ray source 100, a scanning carrier 200, a detector 300, a data processing module 400, and a control module 500.

[0040] The distributed X-ray source 100 is equipped with multiple microfocal points, and the focal line array is parallel to the tomographic imaging plane for emitting X-rays. The scanning carrier 200 carries the object to be detected and translates it into the target scanning area. The detector 300 detects X-ray signals entering the target scanning area and performs signal readout. The data processing module 400 acquires the multifocal projection data generated by the X-ray signals and performs rearrangement, interpolation optimization, and image reconstruction processing on the multifocal projection data to obtain a reconstructed image. The control module 500 controls the distributed X-ray source 100 and the detector 300 to rotate simultaneously around the rotation center relative to the object to be detected, controls the beam output of the distributed X-ray source according to the beam output strategy, and controls the detector 300 to synchronously acquire X-ray signals. The CT imaging system proposed in this embodiment of the invention has advantages such as microfocal points, high power, and high spatial resolution.

[0041] In some embodiments, during the scanning process, the control module 500 controls the data acquisition of the detector 300 to be synchronized with the microfocus switching of the distributed X-ray source 100, and the detector 300 reads the X-ray signal from a microfocus in each frame.

[0042] Specifically, if Figure 2 As shown, during the scanning process, the distributed X-ray source 100 and the detector 300 rotate simultaneously around the rotation center relative to the object under test. Multiple microfoci of the distributed X-ray source 100 emit beams sequentially according to a beam emission strategy. The trajectory can be a straight-line or circular-like trajectory or a spiral-like trajectory. The acquisition by the detector 300 is synchronized with the focus switching of the distributed X-ray source 100; that is, the detector 300 reads only the X-ray signal from one focus per frame. The scanning trajectory of the distributed X-ray source 100 and the sequential emission of beams from multiple microfoci can disperse heat dissipation, significantly reduce the duty cycle of each focus pulse, and effectively improve the X-ray source power and spatial resolution without increasing the focus size.

[0043] It should be noted that during the scanning process, the beams from each focal point of the linear distributed X-ray source emerge sequentially. Therefore, the scanning trajectory is not a standard circular / spiral line, but rather a linear-like circular / spiral trajectory. By setting different beam-emission strategies, various linear-like circular / spiral trajectory scans can be achieved, including but not limited to... Figure 2 The following are some examples of scanning trajectories.

[0044] In some embodiments, the beam emission strategy includes: the beam emission time of the distributed X-ray source, the beam emission interval, the number of switching between focal points, the motion trajectory, and the rotation rate of the distributed X-ray source and the detector relative to the object to be detected.

[0045] In actual implementation, such as Figure 3 As shown, different imaging geometry, focal point arrangement, and distributed light source placement tilt angle affect performance indicators such as image quality, field of view size, and spatial resolution. The field of view size of this system can be expressed as:

[0046]

[0047] Where R is the field radius, L is the width of the detector array, ∆t is the focal interval, N is the number of focal points, and D is the distance from the X-ray source to the detector.

[0048] Sequential beam emission from multiple focal points can significantly reduce the duty cycle of each focal pulse, thereby increasing the overall power of the CT system even with small / microfocal points. The total power of the system can be expressed as the equivalent power of all focal points:

[0049]

[0050] in, The total power of the system. For the first The equivalent power of each focal point, For the first The distance from each focal point to the center of the detector array This represents the distance from the radiation source to the detector. This is the focal interval.

[0051] Based on the relationship between the above parameters and system performance, the embodiments of the present invention pre-optimize the system parameters. For example, three optimization objectives can be selected: image noise, scanning field of view, and spatial resolution, and the overall system optimization can be expressed as a preset optimization objective function:

[0052]

[0053] in, To set the optimization target, These are the design parameters for a CT imaging system, including the number of focal points, focal spacing, distance from each focal point to the center of the detector array, distance from each focal point to the detector, and width of the detector array. This represents the field-of-view size loss function of a CT imaging system; for example, as the focal spot size of the X-ray source increases, the resolution decreases. getting bigger and bigger Let N be the equivalent power loss function of the CT imaging system, representing the loss function with respect to system noise (equivalent power). For example, as N increases, the effective power increases, and the system noise decreases. Let be the field of view loss function of the CT imaging system, representing the loss function for the system's field of view size. For example, as N increases, FOV decreases and 𝑉(𝜃) increases.

[0054] Furthermore, a preset beam-out strategy is determined based on the preset optimization objective function. The beam-out strategy refers to the design of parameters such as beam-out time, beam-out interval, and switching order between different focal points, which can optimize the sampling distribution of multiple focal points. Among them, the beam-out strategy includes, but is not limited to, the following characteristics: beams can be emitted sequentially from each focal point, or beams can be emitted at intervals of several focal points; beams can always be emitted sequentially in one arrangement direction, or beams can be emitted alternately in two arrangement directions; beams can be emitted once from each focal point in one cycle, or beams can be emitted multiple times from each focal point in one cycle; the preset beam-out strategy can also be set to a beam-out cycle, which is continuously cyclical during the scanning process, or it can adaptively and flexibly emit beams according to the characteristics of the detected object, including adjusting the beam intensity and the beam-out switching speed between focal points.

[0055] The beam emission time, beam emission interval, switching order between focal points, and the rotation rate of detector 300 and distributed X-ray source 100 relative to the object under test determine the scanning angle range corresponding to each focal point. Due to the differences in the positions of the multiple focal points, different scanning angle ranges lead to different image qualities. At the same time, the size of the scanning angle range also affects the spatial resolution of the image. The faster the scanning switching, the higher the spatial resolution, but the lower the beam power and the greater the noise.

[0056] like Figure 4 As shown, the sampling space changes caused by different beam-out strategies are used to recover sub-pixel level projection data from the original projection data, achieving high-resolution reconstruction and further improving the spatial resolution of the system.

[0057] The beam-out strategy can be determined by the high-resolution sampling conditions under equidistant sampling, and the specific expression is as follows:

[0058]

[0059] in, and Let be the index of any two foci, and < , and Each is a focal point and focus Relative to the position of the center of the X-ray source array, Focus and focus The misalignment distance of the detector direction during high-resolution sampling. The angle sampling interval is... Let be any integer, representing the number of angular offsets between the two foci, and N be the number of foci. and These represent the distance from the distributed X-ray source to the rotation center and the distance from the distributed X-ray source to the detector, respectively.

[0060] The derivation of the high-resolution sampling conditions under equidistant sampling is as follows:

[0061] In polar coordinate sampling space and These represent the distance from each ray to the center of rotation and the direction of the ray, respectively, and their relationship to the detector pixel position. and perspective The following mapping relationship exists:

[0062]

[0063]

[0064] like Figure 5 As shown, coinciding the sampling of two or more focal points at a certain viewpoint can improve [efficiency / refinement]. The sampling rate in the direction is adjusted to improve spatial resolution. Assuming the focus... and focus The relative distance between them is If the following conditions are met, the sampling of the two focal points can be guaranteed to be the most dense in the detector direction.

[0065]

[0066] in, Focus and focus The angle sampling interval, The focal point is the angular sampling interval between adjacent beam-out cycles in a sequential beam-out scenario. That is, the number of focal points of the radiation source. Let be any integer. Since a larger ∆r results in a smaller high-resolution FOV, therefore... This generally maximizes the high-resolution FOV. Furthermore, since sampling points at different locations on the detector 300 cannot simultaneously satisfy the above conditions, and it is generally desirable to have the highest resolution in the region near the rotation center, based on the above mapping relationship, considering the sampling point at s = 0:

[0067]

[0068]

[0069]

[0070] Combining the above equations yields the high-resolution sampling conditions under equidistant sampling. These high-resolution sampling conditions under equidistant sampling can be extended to combinations of multiple small focal points.

[0071] After obtaining the high-resolution beam output strategy under equidistant sampling, the control module 500 can control the distributed X-ray source 100 to output a beam to the object to be detected according to the beam output strategy, and control the detector 300 to synchronously detect the X-ray signal entering the target scanning area.

[0072] Based on the above, the workflow of the CT imaging system based on a distributed small-focus X-ray source proposed in this embodiment of the invention is as follows:

[0073] A beam strategy is designed in advance based on preset high-resolution sampling conditions. The beam strategy includes the beam emission time of the distributed X-ray source 100, the beam emission interval, the switching order between focal points, and the rotation rate of the distributed X-ray source 100 and the detector 300 relative to the object under test.

[0074] When the CT imaging system is working, the scanning carrier 200 moves the object under test relative to the CT system into the target scanning area. The control module 500 controls the distributed X-ray source and detector to rotate around the rotation center relative to the object under test according to the beam output strategy, and generates a trigger pulse sequence to control each focal point of the distributed X-ray source 100 to emit beams in sequence and the detector 300 to detect the X-ray signal entering the target scanning area. At the same time, the generated trigger pulses are sent to the data processing module 400 to control the timing of data acquisition by the detector 300 and to acquire multifocal projection data. Since the scanning angle ranges of multiple microfocals partially overlap, and the object under test is within the overlapping scanning range, the data processing module 400 performs rearrangement and interpolation optimization on the multifocal projection data, and then performs image reconstruction on the object under test to obtain a reconstructed image.

[0075] The data processing before image reconstruction includes data rearrangement, correction, interpolation optimization, etc. Reconstruction methods include, but are not limited to: independently reconstructing the projection data of each focal point and then performing image fusion; rearranging and interpolating the multifocal projection data and then performing analytical reconstruction; and directly performing iterative reconstruction on the multifocal projection data. Among these, analytical reconstruction after rearrangement and iterative reconstruction are more suitable for high-resolution sampling.

[0076] like Figure 6 and 7 As shown, it can be seen that the sequential beam emission method of the distributed X-ray source in this embodiment of the invention is equivalent to the beam emission method of a single focal point in a traditional single-focal X-ray CT system, resulting in a significant improvement in the signal-to-noise ratio. The reconstructed image obtained by the CT imaging system in this embodiment of the invention has a higher spatial resolution than the reconstructed image obtained by a traditional single-focal X-ray CT system.

[0077] In summary, the CT imaging system based on a distributed small-focus X-ray source proposed in the embodiments of the present invention has the following beneficial effects:

[0078] (1) By sequentially emitting beams from each focal point of the distributed X-ray source, the duty cycle of each focal pulse can be reduced, thereby significantly increasing the peak power of the X-ray source and improving the scanning speed of the micro-focal CT system;

[0079] (2) Allowing the focal size of the X-ray source to be small enough to make the system's limiting spatial resolution sufficiently high;

[0080] (3) By optimizing the design of system parameters and multi-point source beam strategy, sub-pixel level projection data can be recovered from the original projection data, thereby achieving high-resolution reconstruction.

[0081] Next, with reference to the accompanying drawings, a CT imaging method based on a distributed small-focus X-ray source according to an embodiment of the present invention is described.

[0082] Figure 8 This is a schematic flowchart of a CT imaging method based on a distributed small-focus X-ray source according to an embodiment of the present invention.

[0083] like Figure 8 As shown, this CT imaging method based on a distributed small-focus X-ray source includes the following steps:

[0084] In step S801, a beam-out strategy is generated based on preset high-resolution sampling conditions, and the beam-out strategy is set for the control module.

[0085] In step S802, the control module is used to move the object to be detected to the target scanning area, and the distributed X-ray source is controlled to emit beams toward the object to be detected and the detector synchronously acquires multifocal projection data.

[0086] In step S803, the data processing module is used to perform image reconstruction processing on the multifocal projection data to obtain a reconstructed image.

[0087] In some embodiments, the data processing module performs image reconstruction processing on the multifocal projection data to obtain a reconstructed image, including:

[0088] The projection data at each focal point is independently analyzed and reconstructed to obtain multiple reconstructed sub-images. These sub-images are then fused to obtain the reconstructed image.

[0089] The multifocal projection data is rearranged and interpolated to obtain the rearranged high-resolution projection data. The rearranged high-resolution projection data is then analyzed and reconstructed to obtain the reconstructed image; or

[0090] The reconstructed image is obtained by iterative reconstruction of the multifocal projection data.

[0091] It should be noted that the foregoing explanation of the CT imaging method embodiment based on distributed small-focus X-ray sources also applies to the CT imaging device based on distributed small-focus X-ray sources in this embodiment, and will not be repeated here.

[0092] The CT imaging method based on a distributed small-focus X-ray source proposed in this invention has the following advantages:

[0093] (1) By sequentially emitting beams from each focal point of the distributed X-ray source, the duty cycle of each focal pulse can be reduced, thereby significantly increasing the peak power of the X-ray source and improving the scanning speed of the micro-focal CT system;

[0094] (2) Allowing the focal size of the X-ray source to be small enough to make the system's limiting spatial resolution sufficiently high;

[0095] (3) By optimizing the design of system parameters and multi-point source beam strategy, sub-pixel level projection data can be recovered from the original projection data, thereby achieving high-resolution reconstruction.

[0096] Figure 9 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. The electronic device may include:

[0097] The memory 901, the processor 902, and the computer program stored on the memory 901 and capable of running on the processor 902.

[0098] When the processor 902 executes the program, it implements the CT imaging method based on a distributed small-focus X-ray source provided in the above embodiments.

[0099] Furthermore, electronic devices also include:

[0100] Communication interface 903 is used for communication between memory 901 and processor 902.

[0101] The memory 901 is used to store computer programs that can run on the processor 902.

[0102] The memory 901 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0103] If the memory 901, processor 902, and communication interface 903 are implemented independently, then the communication interface 903, memory 901, and processor 902 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of representation, Figure 9 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0104] Optionally, in a specific implementation, if the memory 901, processor 902, and communication interface 903 are integrated on a single chip, then the memory 901, processor 902, and communication interface 903 can communicate with each other through an internal interface.

[0105] The processor 902 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention.

[0106] This invention also provides a computer program product, which, when executed by a processor, implements the above-described CT imaging method based on a distributed microfocus X-ray source.

[0107] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described CT imaging method based on a distributed small-focus X-ray source.

[0108] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0109] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0110] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of the invention pertain.

[0111] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0112] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0113] Those skilled in the art will understand that all or part of the steps of the methods described in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it includes one or a combination of the steps of the method embodiments.

[0114] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0115] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A CT imaging system based on a distributed small-focus X-ray source, characterized in that, include: The system comprises a distributed X-ray source, a scanning carrier, a detector, a data processing module, and a control module. The distributed X-ray source is equipped with multiple microfoci, and the focal line array is parallel to the tomographic imaging plane for emitting X-rays; A scanning carrier is used to move the object to be detected to the target scanning area. A detector used to detect X-ray signals entering the target scanning area; The data processing module is used to acquire multifocal projection data generated by the X-ray signal and perform image reconstruction processing on the multifocal projection data to obtain a reconstructed image. The control module is used to control the beam output of the distributed X-ray source according to the beam output strategy and to control the detector to acquire data of the X-ray signal. The beam output strategy is determined according to preset high-resolution sampling conditions and includes: the beam output time of the distributed X-ray source, the beam output interval, the number of switching between focal points, the motion trajectory, and the rotation rate of the distributed X-ray source and the detector relative to the object to be detected. The preset high-resolution sampling condition is as follows: Based on the distance and direction of each ray from the detector to the rotation center, the relative positions of the detector direction and viewing angle of the rotation center region between each pair of focal points are determined. Then, based on these relative positions, multiple sampling points from each pair of focal points are sampled most densely and equidistantly along the direction of the detector. Specifically, when the relative distance between each pair of focal points is greater than 0, the condition for the multiple sampling points from each pair of focal points to be most densely packed along the direction of the detector is: ； in, and The relative position of the detector direction and the viewing angle in the rotation center region of each pair of focal points. and Let be the index of any two foci, and < , The angle sampling interval is... is any integer, representing the number of angular offsets between the two focal points, and N is the number of focal points of the ray source; During the scanning process, the distributed X-ray source rotates around the rotation center relative to the object to be detected. The multiple microfocal points sequentially emit beams toward the object to be detected according to the beam emission strategy. The detector collects the X-ray signals. The data processing module collects the multifocal projection data generated by the X-ray signals and performs subpixel-level image reconstruction based on the multifocal projection data to obtain the reconstructed image.

2. The CT imaging system based on a distributed small-focus X-ray source according to claim 1, characterized in that, During the scanning process, the control module controls the data acquisition of the detector to be synchronized with the microfocus switching of the distributed X-ray source, and the detector reads the X-ray signal from a microfocus in each frame.

3. The CT imaging system based on a distributed small-focus X-ray source according to claim 1, characterized in that, The motion trajectory includes a linear circular trajectory or a spiral trajectory.

4. The CT imaging system based on a distributed small-focus X-ray source according to claim 3, characterized in that, The expression for the preset high-resolution sampling condition is: in, and Let be the index of any two foci, and < , and Each is a focal point and focus Relative to the position of the center of the X-ray source array, Focus and focus The misalignment distance of the detector direction during high-resolution sampling. The angle sampling interval is... Let be any integer, representing the number of angular offsets between the two foci, and N be the number of foci. and These represent the distance from the distributed X-ray source to the rotation center and the distance from the distributed X-ray source to the detector, respectively.

5. The CT imaging system based on a distributed small-focus X-ray source according to claim 1, characterized in that, The data processing module includes: The projection data for each focal point is independently analyzed and reconstructed to obtain multiple reconstructed sub-images, and these multiple reconstructed sub-images are then fused to obtain the reconstructed image; or The multifocal projection data is rearranged and interpolated to obtain rearranged high-resolution projection data, and the rearranged high-resolution projection data is then analyzed and reconstructed to obtain the reconstructed image; or The reconstructed image is obtained by iteratively reconstructing the multifocal projection data.

6. A CT imaging method based on a distributed small-focus X-ray source, characterized in that, The CT imaging system based on a distributed small-focus X-ray source according to any one of claims 1-5 includes the following steps: A beam-out strategy is generated based on preset high-resolution sampling conditions, and the beam-out strategy is set for the control module. The control module is used to translate the object to be detected to the target scanning area, and to control the distributed X-ray source to emit beams toward the object to be detected and the detector to synchronously acquire multifocal projection data. The multifocal projection data is processed by a data processing module to perform image reconstruction to obtain a reconstructed image.

7. An electronic device, characterized in that, include: The memory, the processor, and the computer program stored in the memory and executable on the processor, the processor executing the program to implement the CT imaging method based on a distributed small-focus X-ray source as described in claim 6.

8. A computer program product, characterized in that, When the computer program / instructions are executed by the processor, they implement the CT imaging method based on a distributed microfocus X-ray source as described in claim 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the CT imaging method based on a distributed microfocus X-ray source as described in claim 6.

Images