CT (Computed Tomography) imaging system and method based on distributed micro-focus X-ray source

Abstract

The invention relates to the technical field of computed tomography, in particular to a CT imaging system and method based on a distributed micro-focus X-ray source, and the system comprises the distributed X-ray source provided with a plurality of micro-focuses, a detector, a scanning carrier, a control module and a data processing module. In the scanning process, the distributed X-ray source and the detector rotate around the rotation center relative to the object to be detected at the same time, the multiple small and micro focuses are sequentially subjected to beam outgoing according to the beam outgoing strategy so as to disperse heat dissipation, the peak power of the small and micro focus radiation source can be effectively improved, and the time needed by single CT scanning is shortened. Besides, by designing a beam outgoing strategy of the distributed X-ray source, sampling distribution of a plurality of small microfocuses can be optimized, sub-pixel-level image reconstruction is realized, and the spatial resolution is further improved. According to the system and the method, ultrafast high-definition CT imaging can be realized, and the problem that a traditional single-focus X-ray CT system is difficult to consider high spatial resolution and high time resolution at the same time is solved.

Description

Technical Field

[0001] The present invention relates to the field of computer tomography technology, and in particular to a CT imaging system and method based on a distributed small micro-focus X-ray source. Background Art

[0002] Computed tomography (CT) is a commonly used non-destructive testing technology that can obtain internal structure information without damaging the object being tested. It is currently widely used in medical imaging, industrial diagnosis, safety inspection and other fields.

[0003] The focal spot size and power of the X-ray source are two important factors that affect the overall performance of the CT system. The focal spot size affects the spatial resolution of the system: the larger the focal spot size, the lower the spatial resolution of the imaging and the blurrier the image; the power size limits the imaging speed: the greater the power, the more X-ray photons irradiate the sample per unit time, and the shorter the exposure time required under the specified signal-to-noise ratio level, the faster the imaging.

[0004] However, there is an antagonistic relationship between the focal spot size and the radiation source power. Commonly used X-ray sources use electrons bombarding the anode target to produce bremsstrahlung to generate X-rays, which generates a lot of heat in the process. If the power per unit area on the target material is too large, the target surface will gradually melt under long-term operation. The tiny X-ray source focus can provide higher spatial resolution, but at the cost of a decrease in the allowed radiation source power, and the time to obtain projection data with an acceptable noise level is greatly extended. Therefore, it is difficult for a single-focus X-ray CT system to simultaneously take into account high spatial resolution and high temporal resolution. Summary of the invention

[0005] The present invention provides a CT imaging system and method based on a distributed small micro-focus X-ray source, so as to solve the problem that a traditional single-focus X-ray CT system is difficult to achieve both high spatial resolution and high temporal resolution.

[0006] A first aspect of the present invention provides a CT imaging system based on a distributed small micro-focus X-ray source, comprising: a distributed X-ray source, a scanning carrier, a detector, a data processing module and a control module, wherein the distributed X-ray source is provided with a plurality of small micro-focuses, and the focus line array is parallel to the tomographic imaging plane, and is used to emit X-rays; the scanning carrier is used to translate the object to be detected to a target scanning area; the detector is used to detect the X-ray signal entering the target scanning area; the data processing module is used to collect multi-focus projection data generated by the X-ray signal, and perform image reconstruction processing on the multi-focus projection data to obtain a reconstructed image; the control module is used to control the distributed X-ray source to emit a beam according to a beam emission strategy, and control the detector to perform data acquisition on the X-ray signal;

[0007] During the scanning process, the distributed X-ray source rotates around the rotation center relative to the object to be detected, and the multiple small micro-focus points sequentially emit beams to the object to be detected according to the beam-emitting strategy. The detector collects the X-ray signal, and the data processing module collects the multi-focus projection data generated by the X-ray signal, and performs sub-pixel level image reconstruction based on the multi-focus 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 switching of the small micro focus of the distributed X-ray source, and the detector reads the X-ray signal from a small micro focus in each frame.

[0009] Optionally, the beam emission strategy is determined according to preset high-resolution sampling conditions, wherein the beam emission strategy includes: the beam emission time, beam emission interval, number of switching times 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 straight line, a circular trajectory, or a spiral trajectory.

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

[0012]

[0013] Among them, i and j are the serial numbers of any two foci, and i <j,r i and r j are the positions of focus i and focus j relative to the center of the ray source array, Δs is the misalignment distance between focus i and focus j in the detector direction during high-resolution sampling, Δβ is the angular sampling interval, n is an arbitrary integer representing the number of misalignments in the viewing direction of the two foci, N is the number of foci, sid and sdd are the distances from the distributed X-ray source to the rotation center and from the distributed X-ray source to the detector, respectively.

[0014] Optionally, the data processing module includes:

[0015] The projection data of each focus is analyzed and reconstructed separately to obtain a plurality of reconstructed sub-images, and the plurality of reconstructed sub-images are fused to obtain the reconstructed image; or

[0016] Rearranging and interpolating the multi-focus projection data to obtain rearranged and interpolated high-resolution projection data, and analytically reconstructing the rearranged and interpolated high-resolution projection data to obtain the reconstructed image; or

[0017] The multi-focus projection data is iteratively reconstructed to obtain the reconstructed image.

[0018] The second aspect of the present invention provides a CT imaging method based on a distributed small micro-focus X-ray source, comprising the following steps: generating a beam emission strategy according to preset high-resolution sampling conditions, and setting the beam emission 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 a beam to the object to be detected and the detector to synchronously collect multi-focus projection data; using a data processing module to perform image reconstruction processing on the multi-focus projection data to obtain a reconstructed image.

[0019] A third aspect of the present invention provides an electronic device, comprising: 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 a CT imaging method based on a distributed small micro-focus X-ray source as described in the above embodiment.

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

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

[0022] The CT imaging system and method based on a distributed micro-focus X-ray source proposed in the embodiment of the present invention adopts a distributed X-ray source and retains the rotation scanning mode of the third-generation CT system, and can simultaneously have the advantages of micro-focus, high power, high spatial resolution, etc.; during the scanning process, the focus at different positions does not need to emit beams continuously, but adopts a method of sequentially emitting beams in multiple focuses, which can greatly reduce the pulse beam emission duty cycle of each focus, thereby significantly improving the peak power of the micro-focus X-ray source, improving the micro-focus CT scanning speed and maintaining the imaging spatial resolution and signal-to-noise ratio; by reasonably designing system parameters and beam emission strategies, the sampling distribution of multiple focuses can be optimized, thereby achieving sub-pixel image reconstruction and further improving spatial resolution.

[0023] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0026] Figure 2 Schematic diagrams of various scanning trajectories provided according to an embodiment of the present invention, wherein (a) is a quasi-circular sequential beam output, (b) is a quasi-circular return beam output, (c) is a quasi-spiral sequential beam output, and (d) is a quasi-spiral instantaneous return beam output;

[0027] Figure 3 A schematic diagram of parameter optimization of a preset optimization target provided according to an embodiment of the present invention;

[0028] Figure 4 Schematic diagram of the spatial comparison between the projection sampling of the multi-point source CT and the projection sampling of the conventional single-point source CT provided in the embodiment of the present invention, wherein (a) is the projection sampling of the conventional single-point source CT, and (b) is the projection sampling of the multi-point source CT;

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

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

[0031] Figure 7 Schematic diagram of high-resolution reconstructed images under the beam-out strategy provided according to an embodiment of the present invention, wherein (a) is a three-focal beam-out reconstruction, (b) is a single-focal beam-out reconstruction, and (c) is a spatial resolution comparison diagram of the three-focal beam-out reconstruction and the three-focal beam-out reconstruction;

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

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

[0034] Description of reference numerals:

[0035] 100 - distributed X-ray source, 200 - scanning carrier, 300 - detector, 400 - data processing module and 500 - control module. DETAILED DESCRIPTION

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

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

[0038] Figure 1 A schematic diagram of the flow of a CT imaging system based on a distributed small micro-focus X-ray source provided in an embodiment of the present invention.

[0039] like Figure 1 As shown, the CT imaging system based on a distributed small 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] Among them, the distributed X-ray source 100 is provided with a plurality of small micro-focus points, and the focus line array is parallel to the tomographic imaging plane, and is used to emit X-rays. The scanning carrier 200 is used to carry the object to be detected and translate the object to be detected to the target scanning area. The detector 300 is used to detect the X-ray signal entering the target scanning area to realize signal readout. The data processing module 400 is used to collect the multi-focus projection data generated by the X-ray signal, and to rearrange, interpolate and optimize the multi-focus projection data and reconstruct the image to obtain a reconstructed image. The control module 500 is used to control the distributed X-ray source 100 and the detector 300 to rotate relative to the object to be detected around the rotation center at the same time, control the distributed X-ray source to emit beams according to the beam emission strategy, and control the detector 300 to synchronously acquire the X-ray signal. The CT imaging system proposed in the embodiment of the present invention has the advantages of micro-focus, high power, high spatial resolution, etc.

[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 switching of the small micro focus of the distributed X-ray source 200, and the detector 300 reads the X-ray signal from a small micro focus in each frame.

[0042] Specifically, Figure 2As shown, during the scanning process, the distributed X-ray source 100 and the detector 300 rotate around the rotation center relative to the object to be measured at the same time, and the multiple small micro-focuses of the distributed X-ray source 100 emit beams in sequence according to the beam emission strategy. The motion trajectory can be a straight-line circular trajectory or a spiral trajectory. The acquisition of the detector 300 is synchronized with the focus switching of the distributed X-ray source 100, that is, the detector 300 only reads the X-ray signal from one focus per frame. The scanning trajectory of the distributed X-ray source 100 and the sequential beam emission of multiple small micro-focuses can disperse the heat dissipation and greatly reduce the pulse beam emission duty cycle of each focus. Without increasing the focus size, it can effectively improve the power and spatial resolution of the ray source.

[0043] It should be noted that during the scanning process, the focal points of the linear distributed X-ray source emit beams in sequence, so the scanning trajectory is not a standard circular line / spiral line, but a linear circular / spiral trajectory. By setting different beam emission strategies, a variety of linear circular / spiral trajectory scanning can be achieved, including but not limited to Figure 2 Several scanning trajectories are shown in Figure .

[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 times 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 the actual implementation process, Figure 3 As shown in the figure, different imaging geometry, focus arrangement, distributed light source placement angle and other parameters 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 of view radius, L is the width of the detector array, Δt is the focus interval, N is the number of focuses, and D is the distance from the ray source to the detector.

[0048] The method of sequentially emitting beams from multiple focal spots can significantly reduce the pulse emission duty cycle of each focal spot, thereby increasing the total power of the CT system in the case of small / micro focal spots. The total power of the system can be expressed by the equivalent power of all focal spots:

[0049]

[0050] Among them, P t is the total system power, P i is the equivalent power of the ith focus, D i is the distance from the ith focus to the center of the detector array, D is the distance from the ray source to the detector, and Δt is the focus interval.

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

[0052]

[0053] in, is the preset optimization target, θ is the design parameter of the CT imaging system, including the number of focal spots, the focal interval, the distance from each focal spot to the center of the detector array, the distance from the focal spot to the detector, and the width of the detector array, etc. R(θ) is the field of view size loss function of the CT imaging system. For example, as the size of the ray source focal spot increases, the resolution decreases, and R(θ) becomes larger and larger. P(θ) is the equivalent power loss function of the CT imaging system, which represents the loss function for the system noise (equivalent power). For example, as N increases, the effective power increases and the system noise decreases. V(θ) is the field of view loss function of the CT imaging system, which represents the loss function for the size of the system field of view. For example, as N increases, the FOV decreases and V(θ) becomes larger.

[0054] Then, the preset beam-out strategy is determined according to the preset optimization objective function. The beam-out strategy refers to the design of parameters such as the beam-out time, beam-out interval, and switching order between focuses of different focuses, which can optimize the sampling distribution of multiple focuses. The beam-out strategy includes but is not limited to the following features: each focus can emit a beam in sequence, or emit a beam at intervals of several focuses; the beam can always be emitted in sequence in one arrangement direction, or the beam can be emitted in two arrangement directions in an interlaced manner; each focus can emit a beam once in a cycle, or each focus can emit a beam multiple times in a cycle; the preset beam-out strategy can also be set as a beam-out cycle, which is continuously cycled during the scanning process, or the beam can be flexibly and adaptively emitted according to the characteristics of the detected object, including adjusting the beam-out intensity, the beam-out switching speed between focuses, etc.

[0055] The beam emission time, beam emission interval, switching order between the focuses, and the rotation rate of the detector 300 and the distributed X-ray source 100 relative to the object to be measured determine the corresponding scanning angle range when each focus emits a beam. Due to the difference in the positions of multiple focuses, different scanning angle ranges lead to different image quality. At the same time, the size of the scanning angle range also affects the spatial resolution of the image. The faster the scanning switch, the higher the spatial resolution, but at the same time, the beam power is lower and the noise is greater.

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

[0057] Among them, the beam-out strategy can be determined by the high-resolution sampling condition under equidistant sampling, and the specific expression is:

[0058]

[0059] Among them, i and i are the serial numbers of any two foci, and i <j,r I and r J are the positions of focus i and focus j relative to the center of the ray source array, Δs is the misalignment distance between focus i and focus j in the detector direction during high-resolution sampling, Δβ is the angular sampling interval, n is an arbitrary integer representing the number of misalignments in the viewing direction of the two foci, N is the number of foci, sid and sdd are the distances from the distributed X-ray source to the rotation center and from the distributed X-ray source to the detector, respectively.

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

[0061] In the polar coordinate sampling space, t and θ represent the distance from each ray to the rotation center and the direction of the ray, respectively, which have the following mapping relationship with the detector pixel position s and the viewing angle β:

[0062]

[0063] like Figure 5 As shown in Figure 1, the sampling rate in the t direction can be increased by making the samples of two or more foci overlap at a certain viewing angle, thereby improving the spatial resolution. Assume that the relative distance between focus i and focus j is Δr = r j -r i >0, then when the following conditions are met, the sampling of the two-focus combination can be guaranteed to be the densest in the detector direction.

[0064] Δθ1+Δθ2=(ji)Δβ+nNΔβ

[0065] Among them, (ji)Δβ is the viewing angle sampling interval of focus i and focus j, NΔβ is the viewing angle sampling interval of the focus in adjacent beam-out periods, in a sequential beam-out situation, N is the number of focal points of the ray source, and n is an arbitrary integer. Since the high-resolution FOV generated when Δr is large is small, therefore, n=0 can generally maximize the high-resolution FOV. In addition, since the sampling points at different positions of the detector 300 cannot meet the above conditions at the same time, and it is generally hoped that the resolution of the area near the rotation center is the highest, therefore, according to the above mapping relationship, the sampling points at s=0 are considered:

[0066]

[0067] By combining the above equations, we can get the high-resolution sampling condition under equidistant sampling, which can be extended to the case of multiple small micro-focus combinations.

[0068] After obtaining a high-resolution beam-emitting strategy under equidistant sampling, the control module 500 can control the distributed X-ray source 100 to emit a beam toward the object to be detected according to the beam-emitting strategy, and control the detector 300 to synchronously detect the X-ray signals entering the target scanning area.

[0069] Based on the above content, the workflow of the CT imaging system based on the distributed small micro-focus X-ray source proposed in the embodiment of the present invention is as follows:

[0070] The beam emission strategy is designed in advance according to the preset high-resolution sampling conditions, and the beam emission strategy includes the beam emission time of the distributed X-ray source 200, the beam emission interval, the switching order between the focal points, and the rotation rate of the distributed X-ray source 200 and the detector 300 relative to the object to be measured.

[0071] When the CT imaging system is working, the scanning carrier 100 translates the object to be detected relative to the CT system into the target scanning area. The control module 500 controls the distributed X-ray source and the detector to rotate relative to the object to be detected around the rotation center at the same time according to the beam emission strategy, and generates a trigger pulse sequence to control each focus of the distributed X-ray source 200 to emit beams in sequence and the detector 300 to detect the X-ray signal entering the target scanning area. The trigger pulse generated at the same time is sent to the data processing module 400 to control the timing of data acquisition by the detector 300 and to collect multi-focus projection data. Since the scanning viewing angle ranges of multiple small micro-focuses partially overlap with each other, the object to be detected is within the overlapping scanning range, so the data processing module 400 rearranges and interpolates and optimizes the multi-focus projection data, and then reconstructs the image of the object to be detected to obtain a reconstructed image.

[0072] Among them, the data processing before image reconstruction includes data rearrangement, correction, interpolation optimization, etc. The reconstruction methods include but are not limited to: independently reconstructing the projection data of each focus, and then performing image fusion; rearranging and interpolating the multi-focus projection data, and then reconstructing the analysis; directly reconstructing the multi-focus projection data iteratively. Among them, analytical reconstruction after rearrangement and iterative reconstruction are more suitable for high-resolution sampling.

[0073] like Figure 6 and 7 As shown, it can be seen that the way in which the focal points of the distributed X-ray source in the embodiment of the present invention emit beams in sequence is equivalent to the beam-emitting way of a single focal point in a traditional single-focus X-ray CT system, and the signal-to-noise ratio is significantly improved. The reconstructed image obtained by the CT imaging system in the embodiment of the present invention is equivalent to the reconstructed image obtained by a traditional single-focus X-ray CT system with higher spatial resolution.

[0074] In summary, the CT imaging system based on a distributed small micro-focus X-ray source proposed in an embodiment of the present invention has the following beneficial effects:

[0075] (1) By sequentially emitting beams from each focus of the distributed X-ray source, the pulse emission duty cycle of each focus can be reduced, thereby significantly increasing the peak power of the X-ray source and improving the scanning speed of the small micro-focus CT system;

[0076] (2) Allowing the focal size of the radiation source to be small enough to make the ultimate spatial resolution of the system high enough;

[0077] (3) By optimizing the design of system parameters and multi-point source beam-out strategies, sub-pixel projection data can be recovered from the original projection data, thereby achieving high-resolution reconstruction.

[0078] Next, a CT imaging method based on a distributed small micro-focus X-ray source according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0079] Figure 8 It is a flowchart of a CT imaging method based on a distributed small micro-focus X-ray source according to an embodiment of the present invention.

[0080] like Figure 8 As shown, the CT imaging method based on a distributed small micro-focus X-ray source includes the following steps:

[0081] In step S801, a beam emission strategy is generated according to a preset high-resolution sampling condition, and the beam emission strategy is set for a control module.

[0082] In step S802, the control module is used to translate the object to be detected to the target scanning area, and the distributed X-ray source is controlled to emit beams to the object to be detected and the detector is controlled to synchronously collect multi-focus projection data.

[0083] In step S803, a data processing module is used to perform image reconstruction processing on the multi-focus projection data to obtain a reconstructed image.

[0084] In some embodiments, performing image reconstruction processing on the multi-focus projection data using a data processing module to obtain a reconstructed image includes:

[0085] The projection data of each focus is analyzed and reconstructed separately to obtain a plurality of reconstructed sub-images, and the plurality of reconstructed sub-images are fused to obtain a reconstructed image; or

[0086] Rearranging and interpolating the multi-focus projection data to obtain rearranged and interpolated high-resolution projection data, and analytically reconstructing the rearranged and interpolated high-resolution projection data to obtain a reconstructed image; or

[0087] The multi-focus projection data are iteratively reconstructed to obtain a reconstructed image.

[0088] It should be noted that the aforementioned explanation of the embodiment of the CT imaging method based on a distributed small micro-focus X-ray source is also applicable to the CT imaging device based on a distributed small micro-focus X-ray source of this embodiment, and will not be repeated here.

[0089] The CT imaging method based on a distributed small micro-focus X-ray source proposed in an embodiment of the present invention has the following beneficial effects:

[0090] (1) By sequentially emitting beams from each focus of the distributed X-ray source, the pulse emission duty cycle of each focus can be reduced, thereby significantly increasing the peak power of the X-ray source and improving the scanning speed of the small micro-focus CT system;

[0091] (2) Allowing the focal size of the radiation source to be small enough to make the ultimate spatial resolution of the system high enough;

[0092] (3) By optimizing the design of system parameters and multi-point source beam-out strategies, sub-pixel projection data can be recovered from the original projection data, thereby achieving high-resolution reconstruction.

[0093] Fig. 9 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. The electronic device may include:

[0094] A memory 901 , a processor 902 , and a computer program stored in the memory 901 and executable on the processor 902 .

[0095] When the processor 902 executes the program, the CT imaging method based on the distributed small micro-focus X-ray source provided in the above embodiment is implemented.

[0096] Furthermore, the electronic device further comprises:

[0097] The communication interface 903 is used for communication between the memory 901 and the processor 902 .

[0098] The memory 901 is used to store computer programs that can be executed on the processor 902 .

[0099] The memory 901 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0100] If the memory 901, the processor 902 and the communication interface 903 are implemented independently, the communication interface 903, the memory 901 and the processor 902 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig. 9 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0101] Optionally, in a specific implementation, if the memory 901, the processor 902 and the communication interface 903 are integrated on a chip, the memory 901, the processor 902 and the communication interface 903 can communicate with each other through an internal interface.

[0102] The processor 902 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present invention.

[0103] An embodiment of the present invention further provides a computer program product, which, when executed by a processor, implements the above-mentioned CT imaging method based on a distributed small micro-focus X-ray source.

[0104] The embodiment of the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned CT imaging method based on a distributed small micro-focus X-ray source.

[0105] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0106] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "N" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0107] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present invention belong.

[0108] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or N wirings (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways as necessary and then storing it in a computer memory.

[0109] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. If implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0110] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0111] In addition, each functional unit in each embodiment of the present invention may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0112] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A CT imaging system based on a distributed small micro-focus X-ray source, characterized in that: include: Distributed X-ray source, scanning carrier, detector, data processing module and control module, wherein: The distributed X-ray source is provided with a plurality of small micro-foci, and the focal line array is parallel to the tomographic imaging plane, for emitting X-rays; A scanning carrier, used to translate the object to be detected to a target scanning area; A detector, used to detect X-ray signals entering the target scanning area; A data processing module, used for collecting multi-focus projection data generated by the X-ray signal, and performing image reconstruction processing on the multi-focus projection data to obtain a reconstructed image; A control module, used for controlling the distributed X-ray source to emit beams according to a beam emission strategy, and controlling the detector to collect data on the X-ray signal; During the scanning process, the distributed X-ray source rotates around the rotation center relative to the object to be detected, and the multiple small micro-focus points sequentially emit beams to the object to be detected according to the beam-emitting strategy. The detector collects the X-ray signal, and the data processing module collects the multi-focus projection data generated by the X-ray signal, and performs sub-pixel level image reconstruction based on the multi-focus projection data to obtain the reconstructed image.

2. The CT imaging system based on a distributed small micro-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 switching of the small micro focus of the distributed X-ray source, and the detector reads the X-ray signal from a small micro focus in each frame.

3. The CT imaging system based on a distributed small micro-focus X-ray source according to claim 1, characterized in that: The beam emission strategy is determined according to preset high-resolution sampling conditions, wherein the beam emission strategy includes: the beam emission time, beam emission interval, number of switching times between focal points, motion trajectory, and rotation rate of the distributed X-ray source and the detector relative to the object to be detected.

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

5. The CT imaging system based on a distributed small micro-focus X-ray source according to claim 3, characterized in that: The expression of the preset high-resolution sampling condition is: Among them, i and j are the serial numbers of any two foci, and i <j,r i and r j are the positions of focus i and focus j relative to the center of the ray source array, Δs is the misalignment distance between focus i and focus j in the detector direction during high-resolution sampling, Δβ is the angular sampling interval, n is an arbitrary integer representing the number of misalignments in the viewing direction of the two foci, N is the number of foci, sid and sdd are the distances from the distributed X-ray source to the rotation center and from the distributed X-ray source to the detector, respectively.

6. The CT imaging system based on a distributed small micro-focus X-ray source according to claim 1, characterized in that: The data processing module comprises: The projection data of each focus is analyzed and reconstructed separately to obtain a plurality of reconstructed sub-images, and the plurality of reconstructed sub-images are fused to obtain the reconstructed image; or Rearranging and interpolating the multi-focus projection data to obtain rearranged and interpolated high-resolution projection data, and analytically reconstructing the rearranged and interpolated high-resolution projection data to obtain the reconstructed image; or The multi-focus projection data is iteratively reconstructed to obtain the reconstructed image.

7. A CT imaging method based on a distributed small micro-focus X-ray source, characterized in that: A CT imaging system based on a distributed small micro-focus X-ray source according to any one of claims 1 to 6 comprises the following steps: Generate a beam-emitting strategy according to a preset high-resolution sampling condition, and set the beam-emitting strategy for a control module; The control module is used to translate the object to be detected to the target scanning area, and the distributed X-ray source is controlled to emit beams to the object to be detected and the detector is controlled to synchronously collect multi-focus projection data; The data processing module is used to perform image reconstruction processing on the multi-focus projection data to obtain a reconstructed image.

8. An electronic device, characterized in that: include: 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 micro-focus X-ray source as described in claim 7.

9. A computer program product, characterized in that When the computer program / instruction is executed by a processor, the CT imaging method based on a distributed small micro-focus X-ray source as described in claim 7 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the CT imaging method based on a distributed small micro-focus X-ray source as described in claim 7.

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