A method for aligning a detector and a radiation source, an imaging system, and a storage medium.

Abstract

This invention relates to the field of detection imaging system technology, and particularly to an alignment method, imaging system, and storage medium for a detector and a radiation source. This invention utilizes a detector to capture multiple projected images of a correction phantom during its movement, extracts a set of projection points formed by the projection of small balls from the correction phantom in the projected images, determines reference lines based on the set of projection points, determines the target position based on multiple reference lines, calculates the offset between the target position and the center of the plane where the detector is located, and controls the detector to move to the target position based on the offset value, thereby completing the alignment of the detector and the radiation source. This method quickly and accurately calculates the offset between the detector and the radiation source, requiring only the movement of the detector according to the offset value to complete the alignment. It is simple to operate, saves time and effort, improves alignment efficiency, and enhances the user experience.

Description

Technical Field

[0001] The present invention relates to the field of detection imaging system technology, and in particular to an alignment method for a detector and a radiation source, an imaging system and a storage medium. Background Technology

[0002] In security inspection, industrial non-destructive testing, and medical imaging fields, precise alignment (or alignment, or orthogonality) of the X-ray source and detector is crucial for ensuring image quality in inspection and imaging systems that include X-ray sources and detectors. Detector and X-ray source alignment refers to the coincidence of the projection of the central X-ray from the X-ray source with the center of the detector's plane. Currently, achieving precise alignment requires repeatedly moving the detector or X-ray source in multiple directions, which is complex, time-consuming, labor-intensive, inefficient, and results in a poor user experience. Summary of the Invention

[0003] In view of this, one objective of the present invention is to provide a method for aligning a detector and a radiation source, an imaging system, and a storage medium to solve the technical problem in the prior art that the detector or radiation source needs to be moved repeatedly when aligning the detector and radiation source, resulting in time-consuming, labor-intensive, and inefficient operation.

[0004] To address the aforementioned technical problems, the embodiments of the present invention provide the following technical solutions:

[0005] In a first aspect, embodiments of the present invention provide an alignment method for a detector and a radiation source, applied to an imaging system. The imaging system includes a detector, a radiation source, and a correction phantom, the correction phantom including a plurality of small balls.

[0006] The method includes:

[0007] The movement of the correction phantom is controlled, and multiple projection images captured by the detector are obtained. The projection images are images of multiple stages during the movement of the correction phantom, and each projection image contains projection points formed by the projection of the small ball.

[0008] Based on the projected image, extract the point set of the projected points in the projected image;

[0009] Determine the reference line based on the set of points projected in the projected image;

[0010] The target position is determined based on multiple reference lines. The target position is the position where the central ray of the radiation source is projected onto the plane where the detector is located.

[0011] Based on the target position, the offset between the target position and the reference position is calculated, where the reference position is the center of the plane where the detector is located;

[0012] Based on the offset value, the detector is controlled to move to the target position, thus completing the alignment of the detector and the radiation source.

[0013] In some embodiments, extracting the point set of projection points in the projection image based on the projection image includes:

[0014] Binarize the projected image;

[0015] Extract the different centroids of the projected points corresponding to the small balls at different positions in the projected image, and use the coordinates of the centroids as the reference coordinates of the projected points corresponding to the small balls;

[0016] Each ball is numbered, and the point set of all balls is obtained based on the number and reference coordinates.

[0017] In some embodiments, determining the reference line based on the set of projection points in the projected image includes:

[0018] Choose any one of the multiple projection points as the target projection point;

[0019] In each projected image, the reference coordinates of the target projection point are determined, resulting in multiple target coordinates;

[0020] Based on multiple target coordinates, obtain the reference line corresponding to the target projection point.

[0021] In some embodiments, determining the target location based on multiple reference lines includes:

[0022] Construct a linear matrix equation based on multiple reference lines;

[0023] Solve the equation of the linear matrix to obtain the intersection point of the reference line; the intersection point is the target position.

[0024] In some embodiments, calculating the offset between the target position and the reference position based on the target position includes:

[0025] Obtain the reference location;

[0026] Calculate the pixel offset distance between the target position and the reference position based on the target position and the reference position;

[0027] Multiply the pixel offset distance by the detector resolution to obtain the offset value between the target position and the reference position.

[0028] In some embodiments, the offset value includes an X-axis offset value and a Y-axis offset value, and controlling the detector to move to the target position based on the offset value includes:

[0029] Based on the X-axis offset value and the Y-axis offset value, the target orientation of the detector relative to the radiation source is determined;

[0030] Based on the target's orientation, the detector is controlled to move by an X-axis offset value and a Y-axis offset value, so that the detector moves to the target position.

[0031] In some embodiments, the imaging system further includes a guide rail disposed between the detector and the X-ray source, a correction phantom passing through the guide rail, and the guide rail having multiple positioning points, with any two positioning points spaced apart by a preset distance.

[0032] The control and correction phantom movement, and the acquisition of multiple projection images captured by the detector, include:

[0033] The control correction model moves along the first direction on the guide rail to each positioning point;

[0034] Upon detecting that the calibration phantom has moved to the positioning point, the detector is controlled to capture projected images, resulting in multiple projected images.

[0035] In some embodiments, before the control correction phantom moves along a first direction on the guide rail to each positioning point, the method further includes:

[0036] The movement of the X-ray source or detector is controlled so that the projected image is within the field of view of the detector. The projected image is the image formed by the X-ray source projecting onto the correction phantom.

[0037] In a second aspect, embodiments of the present invention provide an imaging system, comprising:

[0038] The system includes a controller, a detector, a radiation source, a correction phantom, and a guide rail. The guide rail is vertically positioned between the detector and the radiation source. The correction phantom passes through the guide rail and includes multiple small balls. The guide rail has multiple positioning points, with any two positioning points spaced at a preset distance.

[0039] The controller is communicatively connected to the detector, the radiation source, and the correction phantom, respectively.

[0040] The controller includes:

[0041] A processor and a memory communicatively connected to the processor;

[0042] The memory stores computer program instructions executable by the processor, which, when executed by the processor, cause the controller to perform any of the detector and radiation source alignment methods proposed in the first aspect.

[0043] Thirdly, embodiments of the present invention provide a computer-readable storage medium storing processor-executable computer program instructions, which, when executed by a processor, cause the computer to perform any of the detector and radiation source alignment methods proposed in the first aspect.

[0044] The embodiments of the present invention have the following beneficial effects: Unlike the prior art, the alignment method of the detector and the radiation source provided in the embodiments of the present invention is applied to an imaging system. The imaging system includes a detector, a radiation source, and a calibration phantom. The calibration phantom includes multiple small balls. The method includes: controlling the movement of the calibration phantom and acquiring multiple projection images captured by the detector. The projection images are images of multiple stages during the movement of the calibration phantom. Each projection image contains projection points formed by the projection of the small balls. Based on the projection images, a set of projection points in the projection images is extracted. Based on the set of projection points in the projection images, a reference line is determined. Based on multiple reference lines, a target position is determined. The target position is the position where the center ray of the radiation source is projected onto the plane where the detector is located. Based on the target position, the offset value between the target position and the reference position is calculated. The reference position is the center of the plane where the detector is located. Based on the offset value, the detector is controlled to move to the target position, thus completing the alignment of the detector and the radiation source.

[0045] This invention utilizes a detector to capture multiple projected images of the correction phantom during its movement. The projected images are then used to extract a set of projection points formed by the projections of the small balls on the correction phantom. Reference lines are determined based on this set of projection points, and the target position is determined based on multiple reference lines. Next, the offset between the target position and the center of the plane where the detector is located is calculated. Based on this offset, the detector is moved to the target position, thus aligning the detector and the radiation source. This method quickly and accurately calculates the offset between the detector and the radiation source, requiring only the movement of the detector according to the offset value to complete the alignment. The operation is simple, time-saving, and labor-saving, improving alignment efficiency and enhancing the user experience. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the prior art or embodiments will be briefly introduced below. Obviously, the drawings described below only show some embodiments of the present invention and should not be considered as limiting the scope of protection. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1a This is a schematic diagram illustrating an application scenario of the alignment method between the detector and the radiation source provided in some embodiments of the present invention;

[0048] Figure 1b This is a top view of some embodiments of the present invention when the detector and the radiation source are not aligned;

[0049] Figure 1c This is a projected image captured by the detector in some embodiments of the present invention;

[0050] Figure 1dThis is another projected image captured by the detector in some embodiments of the present invention;

[0051] Figure 2a This is a schematic diagram of the logical structure of an imaging system provided in some embodiments of the present invention;

[0052] Figure 2b This is a three-dimensional structural schematic diagram of an imaging system provided in some embodiments of the present invention;

[0053] Figure 2c These are three views of a calibration phantom in an imaging system provided in some embodiments of the present invention;

[0054] Figure 2d These are three views of a calibration phantom in an imaging system provided in other embodiments of the present invention;

[0055] Figure 2e These are three views of a calibration phantom in an imaging system provided in some embodiments of the present invention;

[0056] Figure 2f This is a schematic diagram of the guide rail structure in an imaging system provided in some embodiments of the present invention;

[0057] Figure 2g This is a schematic diagram of the structure of the controller in an imaging system provided in some embodiments of the present invention;

[0058] Figure 3 This is a flowchart illustrating the alignment method of the detector and the radiation source provided in some embodiments of the present invention;

[0059] Figure 4a These are first projected images captured by the detector in some embodiments of the present invention;

[0060] Figure 4b These are second projected images captured by the detector in some embodiments of the present invention;

[0061] Figure 4c These are third projected images captured by the detector in some embodiments of the present invention;

[0062] Figure 5a This is a schematic diagram showing the positional relationship of the projection points of the projected image in some embodiments of the present invention;

[0063] Figure 5b This is an overlaid projection image obtained by overlaying multiple projection images in some embodiments of the present invention;

[0064] Figure 5c It is a connection Figure 5b A schematic diagram obtained by taking the coordinates of the projection points corresponding to all positions of the small ball in the superimposed projection image shown in the embodiment;

[0065] Figure 6aThis is a three-dimensional schematic diagram of the detector and the radiation source after alignment in some embodiments of the present invention;

[0066] Figure 6b This is a top view of the detector and the radiation source after alignment in some embodiments of the present invention;

[0067] Figure 7 This is a schematic diagram illustrating the positional relationship between the reference position and the target position in some embodiments of the present invention;

[0068] Figure 8 This is a schematic diagram showing the positional relationship between the reference position and the target position in other embodiments of the present invention. Detailed Implementation

[0069] To make the objectives and advantages of the embodiments of the present invention more readily understood, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The detailed description of the embodiments of the present invention in the accompanying drawings is not intended to limit the scope of protection claimed by the present invention, but only to illustrate selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0070] It should be noted that, unless there is a conflict, the various technical features involved in the embodiments of the present invention described below can be combined with each other, and all are within the protection scope of the present invention. Furthermore, although functional modules are divided in the device or structural schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. In addition, the terms "first," "second," "third," and other similar expressions used herein do not limit the data or execution order, but are only for illustrative purposes and to distinguish identical or similar items with substantially the same function and effect, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features.

[0071] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. It should be understood that the term "and / or" as used herein includes any and all combinations of one or more of the listed items.

[0072] In security inspection, industrial non-destructive testing, and medical imaging fields, precise alignment (or alignment, or orthogonality) of the X-ray source and detector is crucial for ensuring image quality in inspection and imaging systems that include X-ray sources and detectors. Alignment between the detector and X-ray source refers to the coincidence of the projection of the central ray from the X-ray source with the center of the plane containing the detector. Currently, achieving precise alignment requires repeatedly moving the detector or X-ray source in multiple directions, which is complex, time-consuming, labor-intensive, inefficient, and results in a poor user experience.

[0073] Therefore, embodiments of the present invention provide an alignment method for a detector and a radiation source, applied to an imaging system. Please refer to [link to relevant documentation]. Figure 1a , Figure 1a The diagram illustrates an application scenario of the alignment method for the detector and the X-ray source provided in some embodiments of the present invention. The imaging system 100 includes a controller ( Figure 1a (Not shown) and a detector 110, a radiation source 120, and a correction phantom 130, which are respectively connected to the controller for communication. The correction phantom 130 includes multiple small balls 131. It is worth noting that the spacing, arrangement, and number of the small balls 131 in the correction phantom 130 can be set according to actual needs. This embodiment of the invention does not impose any specific limitations on this. It should be understood that, in order to ensure the quality of the acquired projected image, the spacing between the small balls 131 should be set within a suitable distance range, preferably any suitable distance between 3 and 8 cm.

[0074] Please see Figure 1b , Figure 1b The diagram schematically shows a top view of the detector 110 when it is not aligned with the radiation source 120. Point O1 is the position of the projection of the center ray of the radiation source 120 onto the plane where the detector 110 is located, and point O2 is the center of the plane where the detector 110 is located. It can be seen that there is a deviation between points O1 and O2, that is, the detector 110 is not aligned with the radiation source 120.

[0075] Specifically, the controller controls the movement of the correction phantom 130 and acquires multiple projected images captured by the detector 110 during the movement of the correction phantom 130. The projected images are images from multiple stages of the movement of the correction phantom 130, and each projected image contains a projection point formed by the projection of the small ball 131. For example, the controller controls the correction phantom 130 to move along a first direction N, wherein the detector 110 captures multiple images of the correction phantom 130 during the movement along the first direction N, obtaining multiple projected images. For further examples, please refer to... Figure 1c and Figure 1d , Figure 1c and Figure 1dProjected images PD1 and PD2, captured by detector 110, are shown respectively. Projected image PD1 includes projection points G1, G2, G3, G4, G5, and G6, where projection point G1 corresponds to position W1, G2 to position W2, G3 to position W3, G4 to position W4, G5 to position W5, and G6 to position W6. Projected image PD2 includes projection points H1, H2, H3, H4, H5, and H6, where projection point H1 corresponds to position W1, H2 to position W2, H3 to position W3, H4 to position W4, H5 to position W5, and H6 to position W6.

[0076] Then, based on the projected images, the point set of the projected points in the projected images is extracted. Each projected image includes the projected points formed by the projection of ball 131, for example, Figure 1c The projected image PD1 shown includes projection points G1, G2, G3, G4, G5, and G6. Figure 1d The projected image PD2 shown includes projection points H1, H2, H3, H4, H5, and H6. For example, an image processing algorithm is used to process all projected images, obtaining the projection points in all images, extracting the centroid coordinates of the projection point at each location, and combining the centroid coordinates of the projection points at corresponding locations in all projected images to obtain the point set corresponding to each location. For example... Figure 1c and Figure 1d In the projected images PD1 and PD2 shown, the centroid coordinates of the projected points G1 and H1 corresponding to position W1 are extracted. These centroid coordinates are then combined to obtain the point set GH1 corresponding to position W1. Similarly, the centroid coordinates of the projected points G2 and H2 corresponding to position W2 are extracted. This process is repeated to obtain the point set corresponding to all positions.

[0077] Next, reference lines are determined based on the set of projected points in the projected image. For example, connecting the centroid coordinates of all points in the set corresponding to each location yields a reference line for that point set. For instance, for location W1, connecting the centroid coordinates of projected points G1 and H1 yields a corresponding reference line. For location W2, connecting the centroid coordinates of projected points G2 and H2 yields a corresponding reference line. This process is repeated for all point sets, resulting in multiple reference lines.

[0078] Next, based on multiple reference lines, the target position is determined, where the target position is the location projected from the center ray of the X-ray source 120 onto the plane where the detector 110 is located. Specifically, a linear equation is constructed for each reference line, and the linear equations of multiple reference lines are combined to obtain a linear matrix equation. Then, the linear matrix equation is solved to obtain the target position.

[0079] Finally, the center of the plane where detector 110 is located (i.e., the reference position) is obtained, and the offset value between the target position and the reference position is calculated based on the target position. Based on the offset value, the controller controls detector 110 to move to the target position, completing the alignment of detector 110 and radiation source 120.

[0080] This invention utilizes a detector to capture multiple projected images of the correction phantom during its movement. The projected images are then used to extract a set of projection points formed by the projections of the small balls on the correction phantom. Reference lines are determined based on this set of projection points, and the target position is determined based on multiple reference lines. Next, the offset between the target position and the center of the plane where the detector is located is calculated. Based on this offset, the detector is moved to the target position, thus aligning the detector and the radiation source. This method quickly and accurately calculates the offset between the detector and the radiation source, requiring only the movement of the detector according to the offset value to complete the alignment. The operation is simple, time-saving, and labor-saving, improving alignment efficiency and enhancing the user experience.

[0081] It should be understood that Figure 1a This illustration merely demonstrates one scenario of aligning the detector and the radiation source using a calibration phantom, and does not limit the structure, type, or number of imaging systems in other applications or embodiments. For example, in some other applications or embodiments, the calibration phantom may move in other directions, such as in the opposite direction of the first direction N, or the detector or radiation source may be moved to acquire a projected image by the detector.

[0082] To facilitate understanding of the alignment method of the detector and the X-ray source provided in the embodiments of the present invention, the imaging system provided in the embodiments of the present invention will first be described in detail.

[0083] Please see Figure 2a , Figure 2a The schematic diagram illustrates the structure of an imaging system provided in some embodiments of the present invention.

[0084] Specifically, such as Figure 2a As shown, the imaging system 100 includes a controller 150, a detector 110, an X-ray source 120, a correction phantom 130, and a guide rail 140. The controller 150 is communicatively connected to the detector 110, the X-ray source 120, and the correction phantom 130.

[0085] Please see Figure 2b A guide rail 140 is vertically positioned between the detector 110 and the radiation source 120. A calibration phantom 130 passes through the guide rail 140 and includes multiple small balls 131. It should be understood that the spacing, arrangement, and number of the small balls 131 in the calibration phantom 130 can be set according to actual needs, and this embodiment of the invention does not impose any limitations in this regard. The guide rail 140 serves as the carrier of the calibration phantom 130, enabling the calibration phantom 130 to move along a stable direction, thereby allowing the detector 110 to capture a high-quality projection image, facilitating alignment between the detector 110 and the radiation source 120.

[0086] In this embodiment of the invention, any suitable material and shape of the correction mold 130 can be selected according to actual needs. For example, please refer to [link to relevant documentation]. Figure 2c , Figure 2d and Figure 2e , Figure 2c , Figure 2d and Figure 2e Three views of the correction phantom 130 provided in some embodiments of the present invention are shown respectively.

[0087] Please see Figure 2f The guide rail 140 is provided with multiple positioning points 141, among which, Figure 2f The guide rail 140 shown has seven positioning points, P1-P7, with a preset distance d between any two positioning points 141. It can be understood that by setting the positioning points 141, when the calibration model 130 moves to each positioning point, the detector 110 is controlled to capture a projected image, thus ensuring that the projection points formed by each ball 131 on the projected image have a certain interval, facilitating the acquisition of the coordinates of each projection point. Obviously, when moving the calibration model 130, it can start from any positioning point or not. If it starts from a positioning point, the detector 110 can capture a projected image when the calibration model 130 begins to move. If it does not start from a positioning point, the detector 110 can capture a projected image when the calibration model 130 moves to a positioning point.

[0088] It is understood that the distance between any two positioning points 141 can be the same or different. In this embodiment of the invention, a preset distance d is set so that subsequent identification of the projection point and calculation of the target position are convenient. In some embodiments, the distance between any two positioning points 141 can also be set differently according to actual needs. Furthermore, Figure 2f This is merely an illustrative representation of the positioning points 141 on the guide rail 140, and does not impose any limitations on the number, location, spacing, or style of the points.

[0089] Please see Figure 2g , Figure 2g The schematic diagram illustrates the structure of the controller in an imaging system provided by some embodiments of the present invention.

[0090] like Figure 2g As shown, the controller 150 includes at least one processor 151 and a memory 152 that are communicatively connected. Figure 2g Taking a processor connected via a bus system 153 as an example, the various components in the controller 150 are coupled together through the bus system 153, which is used to realize communication between the various components. It is easy to understand that the bus system 153 may include not only a data bus, but also a power bus, a control bus, and a status signal bus, etc. However, for clarity and brevity, in... Figure 2g The general labels all buses as Bus System 153. This is understandable. Figure 2g The structures shown in the embodiments are merely illustrative and do not limit the structure of the controller described above. For example, the controller may also include components that are more... Figure 2g The structure shown has more or fewer components, or has the same Figure 2g The diagram shows different configurations of the structure.

[0091] Specifically, processor 151 provides computational and control capabilities to control controller 150 to perform corresponding tasks, such as controlling controller 150 to execute any of the detector and radiation source alignment methods provided in the embodiments of the present invention, or to execute steps in any possible implementation of any of the detector and radiation source alignment methods provided in the embodiments of the present invention. Those skilled in the art will understand that processor 151 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0092] The memory 152, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, instructions, and modules, such as the program, instructions, and modules corresponding to the detector and radiation source alignment method in the embodiments of the present invention. In some embodiments, the memory 152 may include a program storage area and a data storage area. The program storage area may store an operating system, an application program required for at least one function, and the data storage area may store data created according to the use of the processor 151. The processor 151 executes various functional applications and data processing of the controller 150 by running the non-transitory software programs, instructions, and modules stored in the memory 152 to implement any detector and radiation source alignment method provided in the embodiments of the present invention, or to execute the steps in any possible implementation of any detector and radiation source alignment method provided in the embodiments of the present invention. In some embodiments, the memory 152 may include high-speed random access memory and may also include non-transitory memory. For example, at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory 152 may also include memories remotely located relative to the processor 151, which may be connected to the processor 151 via a communication network. Understandably, examples of the aforementioned communication networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0093] As can be understood from the above, the implementing entity of any detector and radiation source alignment method provided in the embodiments of the present invention can be any suitable type of controller with certain computing and control capabilities, for example, it can be implemented by the controller 150 described above. In some feasible implementations, any detector and radiation source alignment method provided in the embodiments of the present invention can be implemented by a processor executing computer program instructions stored in a memory.

[0094] The alignment method of the detector and the radiation source provided in the embodiments of the present invention will be described in detail below with reference to the exemplary application and implementation of the controller provided in the embodiments of the present invention.

[0095] Please see Figure 3 , Figure 3 A flowchart illustrating the alignment method of the detector and the X-ray source provided in some embodiments of the present invention is shown.

[0096] Those skilled in the art will understand that the detector and radiation source alignment method provided in this embodiment of the invention can be applied to the aforementioned controller (e.g., controller 150). Specifically, the execution entity of this detector and radiation source alignment method is one or at least two processors of the controller.

[0097] like Figure 3As shown, the alignment method of the detector and the radiation source includes, but is not limited to, the following steps S100-S600:

[0098] S100: Controls the movement of the correction phantom and acquires multiple projection images captured by the detector.

[0099] In this step, the projected images are images from multiple stages of the correction phantom's movement. "Multiple stages" refers to the process of the detector capturing images multiple times during the control of the correction phantom's movement. Each projected image includes a projection point formed by the projection of a small ball; each small ball corresponds to one projection point, meaning each small ball projects a corresponding projection point in each projected image.

[0100] In this embodiment, when alignment of the detector and the radiation source is required, the calibration phantom is controlled to move along any direction or a predetermined path, and the detector is controlled to capture projection images in multiple stages of movement. When the calibration phantom moves a certain distance, the detector captures a corresponding projection image; after each certain distance the phantom moves, the detector captures a corresponding projection image, thus obtaining multiple projection images. After capturing multiple projection images, the detector sends them to the controller, which then obtains the multiple projection images.

[0101] For example, please see Figure 4a , Figure 4b and Figure 4c , Figure 4a , Figure 4b and Figure 4c The first projection image (i.e., projection image PP1), the second projection image (i.e., projection image PP2), and the third projection image (i.e., projection image PP3) obtained by the detector are shown respectively. This embodiment of the invention employs... Figure 2d The calibration phantom shown was photographed, so the obtained projection image PP1 includes projection points C1 to C8, projection image PP2 includes projection points D1 to D8, and projection image PP3 includes projection points E1 to E8.

[0102] For example, in some embodiments, the movement of the correction phantom is controlled, and multiple projected images captured by the detector are acquired, specifically including but not limited to the following steps S110-S120:

[0103] S110: Control the correction model to move along the first direction on the guide rail to each positioning point.

[0104] S120: In response to the detection that the calibration phantom has moved to the positioning point, the detector is controlled to capture projection images, resulting in multiple projection images.

[0105] In this embodiment, the imaging system also includes a guide rail disposed between the detector and the X-ray source, a correction phantom is disposed on the guide rail, and the guide rail is provided with multiple positioning points, with any two positioning points spaced at a preset distance apart.

[0106] Specifically, the calibration phantom is controlled to move along the guide rail in the first direction, moving to each positioning point. A position sensor or encoder is used to detect whether the phantom has reached the positioning point. For any given positioning point, if the phantom is detected to have moved to that point, a corresponding projection image is captured by the detector. Thus, each time the phantom moves to a positioning point, a corresponding projection image is captured by the detector, resulting in multiple projection images.

[0107] In some embodiments, before the control correction phantom moves along the first direction on the guide rail to each positioning point, the alignment method of the detector and the radiation source further includes, but is not limited to, the following step S101:

[0108] S101: Controls the movement of the X-ray source or detector so that the projected image is within the detector's field of view.

[0109] In this step, the projected image is the image formed by the rays from the X-ray source projecting onto the correction phantom. That is, the rays from the X-ray source are projected onto the plane where the detector is located, pass through the correction phantom, and form an image on the plane where the detector is located.

[0110] Specifically, to enable the detector to capture projected images, before the control correction phantom moves along the guide rail in the first direction to each positioning point, the X-ray source or detector is moved and projected images are captured in real time to determine whether the captured projected images are within the detector's field of view. If the projected image is not within the detector's field of view, the position of the X-ray source or detector continues to be moved and adjusted until the projected image is within the detector's field of view.

[0111] S200: Extract the point set of projection points in the projection image based on the projection image.

[0112] Specifically, the projected images are processed to identify and extract the locations of projection points formed by multiple spheres from each image. For example, the projected images are converted to grayscale, and noise is removed using methods such as Gaussian filtering and median filtering. Histogram equalization or adaptive contrast enhancement techniques are used to enhance the difference between the sphere projection points and the background. Then, an edge detection algorithm (such as the Canny algorithm) is used to identify contours in the grayscale image. Based on the circular or near-circular shape of the sphere projection points, the Hough transform method is used to detect circular regions in the grayscale image, and the centroid coordinates of each identified projection point region (circular region) are calculated. These centroid coordinates are used as the coordinates of the projection point in the grayscale image. Finally, based on the sphere's position, the coordinates of the projection points corresponding to the spheres at all identified positions in all projected images are combined to obtain a point set of projection points corresponding to each sphere position. This point set is used for subsequent fitting of a reference line.

[0113] For example, please see Figure 5a The projection points C1 to C8 of the projected image PP1 (projection points D1 to D8 of the projected image PP2 / projection points E1 to E8 of the projected image PP3) correspond to the ball 1 at position AD1, the ball 2 at position AD2, the ball 3 at position AD3, the ball 4 at position AD4, the ball 5 at position AD5, the ball 6 at position AD6, the ball 7 at position AD7, and the ball 8 at position AD8, respectively.

[0114] Please see Figure 5b , Figure 5b The diagram shows the point sets corresponding to the projection points of the balls at all positions. Specifically, the coordinates of the projection points C1, D1, and E1 corresponding to ball 1 at position AD1 form the first point set CDE1; the coordinates of the projection points C2, D2, and E2 corresponding to ball 2 at position AD2 form the second point set CDE2; the coordinates of the projection points C3, D3, and E3 corresponding to ball 3 at position AD3 form the third point set CDE3; the coordinates of the projection points C4, D4, and E4 corresponding to ball 4 at position AD4 form the fourth point set CDE4; the coordinates of the projection points C5, D5, and E5 corresponding to ball 5 at position AD5 form the fifth point set CDE5; the coordinates of the projection points C6, D6, and E6 corresponding to ball 6 at position AD6 form the sixth point set CDE6; the coordinates of the projection points C7, D7, and E7 corresponding to ball 7 at position AD7 form the seventh point set CDE7; and the coordinates of the projection points C8, D8, and E8 corresponding to ball 8 at position AD8 form the eighth point set CDE8. Understandably... Figure 5bThe schematic diagram shown is an image formed by superimposing the projection images PP1, PP2, and PP3 on the center of the detector (i.e., point O2). This facilitates the extraction of the point set of projection points corresponding to the small ball at each position, and also helps to determine the reference line based on the point set of projection points.

[0115] In some embodiments, a set of projection points in the projection image is extracted based on the projection image, specifically including but not limited to the following steps S210-S230:

[0116] S210: Perform binarization processing on the projected image.

[0117] S220: Extract the different centroids of the projected points corresponding to the small balls at different positions in the projected image, and use the coordinates of the centroids as the reference coordinates of the projected points corresponding to the small balls.

[0118] S230: Number each ball and obtain the point set of all balls based on the number and reference coordinates.

[0119] Specifically, each projected image is binarized, that is, converted into a binary image with only two pixel values ​​(usually 0 and 255, i.e., black and white). First, the projected image is converted into a grayscale image to eliminate color interference. Then, the Otsu algorithm, P-Tile algorithm, or any other suitable method or approach is used to calculate a reasonable pixel segmentation threshold. Finally, pixel values ​​greater than or equal to the pixel segmentation threshold are set to the maximum pixel value of 255 (i.e., white), and pixel values ​​less than the pixel segmentation threshold are set to the minimum pixel value of 255 (i.e., black), resulting in the binarized projected image (hereinafter referred to as the reference projected image).

[0120] In this embodiment, a connected component analysis algorithm is used to perform connected component analysis on the reference projection image, identify the connected components in the reference projection image, and extract the centroids of the connected components. The connected component is the projection point, and the centroid of the connected component is the centroid of the projection point. Thus, multiple different centroids of the projection points corresponding to the balls at all positions are obtained, and the coordinates of the centroid of the projection point corresponding to the ball at each position are used as the reference coordinates of the projection point corresponding to the ball.

[0121] Specifically, each ball is numbered, and based on the ball's number and the reference coordinates of its corresponding projection point, the point set of projection points corresponding to all positions of the ball is obtained. That is, by combining the reference coordinates of the projection points corresponding to each numbered ball, the point set of projection points corresponding to that numbered ball is obtained, thus yielding the point set of projection points corresponding to all positions of the ball.

[0122] For example, please see Figure 5a and Figure 5bThe ball at position AD1 is numbered 1, and the reference coordinates of its corresponding projection points C1, D1, and E1 form the first point set CDE1 (i.e., the set of projection points corresponding to ball 1). The ball at position AD2 is numbered 2, and the reference coordinates of its corresponding projection points C2, D2, and E2 form the second point set CDE2 (i.e., the set of projection points corresponding to ball 2). The ball at position AD3 is numbered 3, and the reference coordinates of its corresponding projection points C3, D3, and E3 form the third point set CDE3 (i.e., the set of projection points corresponding to ball 3). The ball at position AD4 is numbered 4, and the reference coordinates of its corresponding projection points C4, D4, and E4 form the fourth point set CDE4 (i.e., the set of projection points corresponding to ball 4). The ball at position AD5 is numbered 5, and the reference coordinates of its corresponding projection points C5, D5, and E5 form the fifth point set CDE5 (i.e., the set of projection points corresponding to ball 5). The ball at position AD6 is numbered 6. The reference coordinates of the projection points C6, D6, and E6 corresponding to ball 6 constitute the sixth point set CDE6 (i.e., the point set of projection points corresponding to ball 6). The ball at position AD7 is numbered 7. The reference coordinates of the projection points C7, D7, and E7 corresponding to ball 7 constitute the seventh point set CDE7 (i.e., the point set of projection points corresponding to ball 7). The ball at position AD8 is numbered 8. The reference coordinates of the projection points C8, D8, and E8 corresponding to ball 8 constitute the eighth point set CDE8 (i.e., the point set of projection points corresponding to ball 8).

[0123] S300: Determine the reference line based on the point set of the projected points in the projected image.

[0124] In this embodiment of the invention, for all projected images, the coordinates of the projection points corresponding to the balls at all positions are extracted and denoted as a point set. , , For the first The coordinates of the projection points corresponding to all positions of the small ball in the projected image. The number of projected images, For the first in the projected image The coordinates of the projection points corresponding to the small balls at each position. The number of balls, i.e., the number of projection points. , Connect the coordinates of the projection points corresponding to each ball position to obtain a corresponding reference line. Connect the coordinates of the projection points corresponding to all balls positions to obtain multiple reference lines.

[0125] For example, please see Figure 5c , Figure 5c The connection is shown. Figure 5b The schematic diagram is obtained by taking the coordinates of the projection points corresponding to all positions of the small ball. Figure 5cThis includes eight reference lines: L1, L2, L3, L4, L5, L6, L7, and L8. Reference line L1 is obtained by connecting the coordinates of the projection points C1, D1, and E1 corresponding to ball 1 at position AD1; reference line L2 is obtained by connecting the coordinates of the projection points C2, D2, and E2 corresponding to ball 2 at position AD2; and reference line L3 is obtained by connecting the coordinates of the projection points C3, D3, and E3 corresponding to ball 3 at position AD3. Reference line L4 is obtained by connecting the coordinates of the projection points C4, D4 and E4 corresponding to ball 4 at position AD4; reference line L5 is obtained by connecting the coordinates of the projection points C5, D5 and E5 corresponding to ball 5 at position AD5; reference line L6 is obtained by connecting the coordinates of the projection points C6, D6 and E6 corresponding to ball 6 at position AD6; reference line L7 is obtained by connecting the coordinates of the projection points C7, D7 and E7 corresponding to ball 7 at position AD7; and reference line L8 is obtained by connecting the coordinates of the projection points C8, D8 and E8 corresponding to ball 8 at position AD8.

[0126] It should be understood that Figure 5c The markings for each projection point are omitted; the corresponding spheres and markings are... Figure 5b The balls and markers at the corresponding positions shown are the same.

[0127] In some embodiments, a reference line is determined based on the set of points projected in the projected image, including but not limited to the following steps S310-S330:

[0128] S310: Select any one of the multiple projection points as the target projection point.

[0129] S320: Determine the reference coordinates of the target projection point in each projected image to obtain multiple target coordinates.

[0130] S330: Based on multiple target coordinates, obtain the reference line corresponding to the target projection point.

[0131] For example, for any projected image, any one of the multiple projection points of that image is selected as the target projection point. The target projection point is the projection point corresponding to the target ball, and the target ball is any one of the multiple balls. For example, it could be... Figure 5a The small ball 1 shown.

[0132] Specifically, after determining the target projection point, the reference coordinates of the target projection point are determined in each projection image to obtain multiple target coordinates. That is, the reference coordinates of the target projection point corresponding to the target ball in each projection image are used as the target coordinates to obtain multiple target coordinates.

[0133] In this embodiment, multiple target coordinates are connected to obtain a reference line corresponding to the target projection point. That is, the reference coordinates (i.e., target coordinates) of the target projection point corresponding to each target ball are connected to obtain a corresponding reference line. After connecting the reference coordinates (i.e., target coordinates) of the target projection points corresponding to all target balls, multiple reference lines are obtained.

[0134] For example, please see Figure 5a , Figure 5b and Figure 5c Select projection point C1 in projection image PP1 as the target projection point. Projection point C1 is the projection point corresponding to ball 1. Ball 1 is the target ball. Determine the reference coordinates of the target projection points (i.e., projection points D1 and E1) corresponding to ball 1 in projection images PP2 and PP3. Obtain multiple target coordinates (i.e., reference coordinates of projection points C1, D1, and E1). Connect the multiple target coordinates to obtain a corresponding reference line L1.

[0135] S400: Determines the target position based on multiple reference lines.

[0136] In this embodiment of the invention, the target position is the location where the central ray of the radiation source is projected onto the plane where the detector is located. It can be understood that multiple reference lines tend to point towards or surround the projection point of the central ray of the radiation source onto the plane where the detector is located; that is, the projection position of the central ray of the radiation source onto the plane where the detector is located is at or near the intersection of multiple reference lines.

[0137] Specifically, any two reference lines are selected from multiple reference lines. and And solve for the reference line. and The intersection points, in total, yielded One intersection point, The number of reference lines is determined. Then, it is determined whether all intersection points are concentrated in a certain area. If they are concentrated in a certain area, it indicates that this area is the projection point of the central ray of the radiation source onto the detector's plane. Finally, the target position is determined based on all intersection points; that is, the mean of the x-coordinates and y-coordinates of all intersection points is taken as the target position. In some embodiments, the target position is calculated by minimizing the total distance from a point to all reference lines. A point is found that minimizes the sum of its distances to all reference lines; this target point is the target position.

[0138] For example, please see Figure 5c Point O1 is the target location, where point O1 is the intersection of multiple reference lines.

[0139] In some embodiments, the target position is determined based on multiple reference lines, including but not limited to the following steps S410-S420:

[0140] S410: Construct a linear matrix equation based on multiple reference lines.

[0141] S420: Solve the equation of the linear matrix to obtain the intersection point of the reference line.

[0142] In this step, the intersection point is the target location.

[0143] Specifically, for the set of projection points corresponding to each ball, a fitting straight line is constructed. The fitted line is the reference line. It is a direction vector. For the first The set of projection points corresponding to each small ball corresponds to the fitted line constructed. Let... , Then the equation of each fitted line is:

[0144]

[0145] Based on all the fitted lines, construct the linear matrix equation. :

[0146] in, ,

[0147] ,

[0148]

[0149] Specifically, the equation of the above linear matrix is ​​solved using the least squares method or any other suitable method to obtain... , coordinates in This refers to the intersection of the reference lines (i.e., the target position). Understandably, in practice, the position of the projected point of the ball may have errors. Therefore, it is necessary to use the least squares method to find the coordinates of the target point that is closest to the sum of all the reference lines. The coordinates of this target point are the coordinates of the target position.

[0150] S500: Calculate the offset between the target position and the reference position based on the target position.

[0151] In this step, the reference position is the center of the plane where the detector is located, that is, the ideal position (or standard position) where the central ray of the ray source is projected onto the plane where the detector is located after the ray source and the detector are aligned.

[0152] Specifically, the center coordinates (i.e., the reference position) of the plane where the detector is located are obtained. These coordinates are fixed and known in the detector's imaging coordinate system, and the center coordinates are half the width and half the height of the projected image. Based on the coordinates of the reference position and the target position, the offset between the target position and the reference position is calculated using the distance calculation formula.

[0153] For example, in some embodiments, the offset between the target position and the reference position is calculated based on the target position, specifically including but not limited to the following steps S510-S530:

[0154] S510: Obtain reference position.

[0155] S520: Calculate the pixel offset distance between the target position and the reference position based on the target position and the reference position.

[0156] S530: Multiply the pixel offset distance by the detector resolution to obtain the offset value between the target position and the reference position.

[0157] Specifically, obtaining the center of the plane where the detector is located (i.e., the reference position) can be understood as follows: after the detector has come to a smooth stop, the center of the plane where the detector is located can be determined. This can be achieved by the detector sending the center of its plane to the controller, or by the controller actively obtaining the center of the plane where the detector is located from the detector.

[0158] Specifically, the coordinates of the target position and the reference position are substituted into the distance calculation formula, such as the Euclidean distance formula, to calculate the pixel offset distance between the target position and the reference position. The pixel offset distance is the distance in the detector's pixel coordinate system. Then, the detector's resolution is obtained, and the pixel offset distance is multiplied by the detector's resolution to obtain the offset value between the target position and the reference position, where the offset value is the distance in the real-world physical coordinate system.

[0159] S600: Based on the offset value, control the detector to move to the target position and complete the alignment of the detector and the radiation source.

[0160] Specifically, after calculating the offset value, the detector is controlled to move along the X-axis / Y-axis to the target position, so that the center of the plane where the detector is located coincides with the projection position of the center ray of the X-ray source on the plane where the detector is located, thereby achieving precise alignment of the detector and the X-ray source. In some embodiments, after the movement is completed, the current position of the detector can be read by a position feedback sensor or encoder to verify whether the target position has been reached, and fine-tuning compensation can be performed if necessary to ensure that the detector and the X-ray source are truly aligned.

[0161] For example, please see Figure 6a as well as Figure 6b , Figure 6aA three-dimensional schematic diagram is shown after the detector and the X-ray source are aligned. Figure 6b A top view is shown after the detector is aligned with the X-ray source. Figure 6a By omitting components such as guide rails and correction phantoms in the imaging system, after the detector is aligned with the X-ray source, the center of the plane where the detector is located (i.e., the reference position / point O2) coincides with the projection position of the central ray 121 of the X-ray source on the plane where the detector is located (i.e., the target position / point O1).

[0162] In some embodiments, the detector is controlled to move to the target position based on the offset value, specifically including but not limited to the following steps S610-S620:

[0163] S610: Determine the target orientation of the detector relative to the radiation source based on the X-axis offset value and the Y-axis offset value.

[0164] In this embodiment, the offset value includes the X-axis offset value and the Y-axis offset value. The target orientation characterizes the relative positional relationship between the center of the detector plane and the projection position of the central ray of the radiation source on the detector plane.

[0165] In this embodiment of the invention, a coordinate system is established with the reference position (i.e., the center of the plane where the detector is located) as the origin. The X-axis offset value is the horizontal offset of the target position (i.e., the projection position of the center ray of the X-ray source on the plane where the detector is located) relative to the reference position, and the Y-axis offset value is the vertical offset of the target position relative to the reference position.

[0166] Specifically, based on the signs of the X-axis and Y-axis offset values, the directional quadrant of the target position relative to the reference position is determined. For example, please refer to... Figure 7 and Figure 8 , Figure 7 and Figure 8 The diagram illustrates the positional relationship between the reference position and the target position in the coordinate system from a top-down perspective, with point O2 representing the reference position and point O1 representing the target position.

[0167] See Figure 7 As shown in 'a', if both the X-axis offset and Y-axis offset values ​​are positive, then the target orientation is such that the detector is located to the lower left of the radiation source, and the detector should move to the upper right.

[0168] See Figure 7 As shown in b, if the X-axis offset is positive and the Y-axis offset is negative, then the target orientation is such that the detector is located to the upper left of the radiation source, and the detector should move to the lower right.

[0169] See Figure 7 As shown in c, if both the X-axis offset and the Y-axis offset are negative, then the target orientation is such that the detector is located to the upper right of the radiation source, and the detector should move to the lower left.

[0170] See Figure 7 As shown in d, if the X-axis offset value is negative and the Y-axis offset value is positive, then the target orientation is such that the detector is located to the lower right of the radiation source, and the detector should move to the upper left.

[0171] See Figure 8 As shown in 'a', if the X-axis offset is 0 and the Y-axis offset is positive, then the target orientation is such that the detector is directly below the radiation source, and the detector should move directly upwards.

[0172] See Figure 8 As shown in b, if the X-axis offset is 0 and the Y-axis offset is negative, then the target orientation is such that the detector is directly above the radiation source, and the detector should move directly downwards.

[0173] See Figure 8 As shown in c, if the X-axis offset is positive and the Y-axis offset is 0, then the target orientation is such that the detector is located directly to the left of the radiation source, and the detector should move directly to the right.

[0174] See Figure 8 As shown in d, if the X-axis offset is negative and the Y-axis offset is 0, then the target orientation is such that the detector is located directly to the right of the radiation source, and the detector should move directly to the left.

[0175] S620: Based on the target orientation, control the detector to move by an X-axis offset value and a Y-axis offset value, so that the detector moves to the target position.

[0176] In this embodiment, when the target orientation is such that the detector is located to the lower left of the radiation source, the detector is controlled to move to the upper right, that is, the detector is controlled to move to the right by the absolute value of the X-axis offset and to the upper right by the absolute value of the Y-axis offset, so that the detector moves to the target position.

[0177] When the target is located above and to the left of the radiation source, the detector is controlled to move to the lower right. This means the detector is moved to the absolute value of the X-axis offset to the right and to the absolute value of the Y-axis offset to the lower right, so that the detector moves to the target position.

[0178] When the target is located above and to the right of the radiation source, the detector is controlled to move to the lower left. That is, the detector is controlled to move to the left by the absolute value of the X-axis offset and to the lower left by the absolute value of the Y-axis offset, so that the detector moves to the target position.

[0179] When the target is located to the lower right of the radiation source, the detector is moved to the upper left. This means the detector is moved to the left by the absolute value of the X-axis offset and to the upper right by the absolute value of the Y-axis offset, so that the detector moves to the target position.

[0180] When the target is located directly below the radiation source, the detector is controlled to move upwards by the absolute value of the Y-axis offset, thus moving the detector to the target position.

[0181] When the target is located directly above the radiation source, the detector is controlled to move directly downwards, that is, the detector is controlled to move downwards by the absolute value of the Y-axis offset, so that the detector moves to the target position.

[0182] When the target is located to the left of the radiation source, the detector is moved to the right by controlling the absolute value of the X-axis offset to move it to the target position.

[0183] When the target is located directly to the right of the radiation source, the detector is controlled to move directly to the left. That is, the detector is controlled to move to the left by the absolute value of the X-axis offset value, so that the detector moves to the target position.

[0184] Understandably, the embodiments of the present invention establish a coordinate system with the reference position (i.e., the center of the plane where the detector is located) as the origin, and determine the target orientation of the detector relative to the radiation source and the direction of movement of the detector in the coordinate system under the top view. Those skilled in the art can also establish different coordinate systems according to actual needs, and determine the target orientation and the direction of movement of the detector in the coordinate system under different viewpoints. The embodiments of the present invention do not limit this in any way.

[0185] It should also be noted that the embodiments of the present invention are illustrated by moving the detector to the target position to align the detector and the radiation source. Those skilled in the art can also move the radiation source to the reference position to align the detector and the radiation source according to actual needs.

[0186] In summary, the detector and radiation source alignment method provided in this embodiment of the invention is applied to an imaging system. The imaging system includes a detector, a radiation source, and a calibration phantom. The calibration phantom includes multiple small balls. The method includes: controlling the movement of the calibration phantom and acquiring multiple projection images captured by the detector. The projection images are images of multiple stages during the movement of the calibration phantom. Each projection image contains projection points formed by the projection of the small balls. Based on the projection images, a set of projection points in the projection images is extracted. Based on the set of projection points in the projection images, a reference line is determined. Based on the multiple reference lines, a target position is determined. The target position is the position where the center ray of the radiation source is projected onto the plane where the detector is located. Based on the target position, the offset value between the target position and the reference position is calculated. The reference position is the center of the plane where the detector is located. Based on the offset value, the detector is controlled to move to the target position, thus completing the alignment of the detector and the radiation source.

[0187] This invention utilizes a detector to capture multiple projected images of the correction phantom during its movement. The projected images are then used to extract a set of projection points formed by the projections of the small balls on the correction phantom. Reference lines are determined based on this set of projection points, and the target position is determined based on multiple reference lines. Next, the offset between the target position and the center of the plane where the detector is located is calculated. Based on this offset, the detector is moved to the target position, thus aligning the detector and the radiation source. This method quickly and accurately calculates the offset between the detector and the radiation source, requiring only the movement of the detector according to the offset value to complete the alignment. The operation is simple, time-saving, and labor-saving, improving alignment efficiency and enhancing the user experience.

[0188] This invention provides a computer-readable storage medium storing processor-executable computer program instructions. When executed by a processor, the computer program instructions cause the computer to perform any of the detector and radiation source alignment methods provided in this invention, or to perform the steps in any of the detector and radiation source alignment methods provided in this invention.

[0189] Those skilled in the art will understand that the embodiments provided by this invention are merely illustrative. The order in which the steps in the methods of the embodiments are written does not imply a strict execution order and does not constitute any limitation on the implementation process. The order can be adjusted, merged, and deleted according to actual needs. Modules or sub-modules, units or sub-units in the apparatus or system of the embodiments can be merged, divided, and deleted according to actual needs. For example, the division of units is only a logical functional division, and there may be other division methods in actual implementation. For another example, multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.

[0190] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software and a general-purpose hardware platform, or it can be implemented using hardware. Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This computer program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0191] It should be noted that the above embodiments are for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can understand that all or part of the processes of the above embodiments can be implemented by modifying the technical solutions described in the embodiments of the present invention, or by making equivalent substitutions for some of the technical features. It is understood that these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and should be considered as equivalent changes and modifications made based on the embodiments of the present invention, all of which should fall within the scope of the claims of the present invention.

Claims

1. A method for aligning a detector and a radiation source, applied to an imaging system, characterized in that, The imaging system includes a detector, a radiation source, and a correction phantom, which consists of multiple small spheres. The method includes: The movement of the correction phantom is controlled, and multiple projection images captured by the detector are obtained. The projection images are images of multiple stages during the movement of the correction phantom, and each projection image contains projection points formed by the projection of the small ball. Based on the projection image, the point set of the projection points in the projection image is extracted, including: performing binarization processing on the projection image, extracting the different centroids of the projection points corresponding to the small balls at different positions in the projection image, using the coordinates of the centroids as the reference coordinates of the projection points corresponding to the small balls, numbering each small ball, and obtaining the point set of all small balls according to the number and the reference coordinates. Determine a reference line based on the set of projection points in the projection image, including: selecting any one of multiple projection points as the target projection point, determining the reference coordinates of the target projection point in each projection image, obtaining multiple target coordinates, and obtaining the reference line corresponding to the target projection point based on the multiple target coordinates. The target position is determined based on multiple reference lines. The target position is the position where the central ray of the radiation source is projected onto the plane where the detector is located. Based on the target position, the offset between the target position and the reference position is calculated, where the reference position is the center of the plane where the detector is located; Based on the offset value, the detector is controlled to move to the target position, thus completing the alignment of the detector and the radiation source.

2. The method according to claim 1, characterized in that, The determination of the target position based on multiple reference lines includes: Construct a linear matrix equation based on multiple reference lines; Solve the equation of the linear matrix to obtain the intersection point of the reference line; the intersection point is the target position.

3. The method according to claim 1, characterized in that, The step of calculating the offset between the target position and the reference position based on the target position includes: Obtain a reference location; Calculate the pixel offset distance between the target position and the reference position based on the target position and the reference position; Multiply the pixel offset distance by the detector resolution to obtain the offset value between the target position and the reference position.

4. The method according to claim 1, characterized in that, The offset value includes an X-axis offset value and a Y-axis offset value. The step of controlling the detector to move to the target position based on the offset value includes: Based on the X-axis offset value and the Y-axis offset value, the target orientation of the detector relative to the radiation source is determined; Based on the target's orientation, the detector is controlled to move by an X-axis offset value and a Y-axis offset value, so that the detector moves to the target position.

5. The method according to claim 1, characterized in that, The imaging system also includes a guide rail between the detector and the X-ray source, a correction phantom is mounted on the guide rail, and the guide rail has multiple positioning points, with a preset distance between any two positioning points; The control and correction phantom movement, and the acquisition of multiple projection images captured by the detector, include: The control correction model moves along the first direction on the guide rail to each positioning point; Upon detecting that the calibration phantom has moved to the positioning point, the detector is controlled to capture projected images, resulting in multiple projected images.

6. The method according to claim 5, characterized in that, Before the control and correction model moves along the first direction on the guide rail to each positioning point, the method further includes: The movement of the X-ray source or detector is controlled so that the projected image is within the field of view of the detector. The projected image is the image formed by the X-ray source projecting onto the correction phantom.

7. An imaging system, characterized in that, include: The system includes a controller, a detector, a radiation source, a correction phantom, and a guide rail. The guide rail is vertically positioned between the detector and the radiation source. The correction phantom passes through the guide rail and includes multiple small balls. The guide rail has multiple positioning points, with any two positioning points spaced at a preset distance. The controller is communicatively connected to the detector, the radiation source, and the correction phantom, respectively. The controller includes: A processor and a memory communicatively connected to the processor; The memory stores computer program instructions executable by the processor, which, when executed by the processor, cause the controller to perform the alignment method of the detector and the radiation source as described in any one of claims 1-6.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores processor-executable computer program instructions, which, when executed by the processor, cause the computer to perform the alignment method of the detector and the radiation source as described in any one of claims 1-6.

Images