Mould positioning method and device, computer equipment, storage medium and program product

Abstract

The application relates to a phantom positioning method and device, computer equipment, a storage medium and a program product. A phantom is provided with at least one set of positioning ball pairs, each set of positioning ball pairs comprising two positioning balls, the two positioning balls in the positioning ball pair being arranged on two sides of a center surface of the phantom and having equal distances from the center surface; the center surface of the phantom is parallel to a center surface of a detector; the method comprises the following steps: acquiring an original scanning image of the phantom in an initial position; determining a distance difference between the two positioning balls in the positioning ball pair and the center surface of the detector based on the original scanning image and position information of the center surface of the detector; determining movement information of the phantom according to the distance difference, and adjusting the position of the phantom according to the movement information of the phantom. In the method, only one original scanning image of the phantom in the initial position is required to realize the positioning adjustment of the phantom, so that the center surface of the phantom is ensured to coincide with the center surface of the detector, and the efficiency and accuracy of the positioning adjustment of the phantom are improved.

Description

Technical Field

[0001] This application relates to the field of medical imaging technology, and in particular to a phantom positioning method, apparatus, computer equipment, storage medium, and program product. Background Technology

[0002] Computed Tomography (CT) is a commonly used imaging technology in the medical field. In order to ensure the accuracy of CT imaging system scanning, it is often necessary to use a geometric correction phantom to correct the CT imaging system. When performing correction, the first thing to do is to ensure that the geometric correction phantom is centered in the field of view (FOV) of the CT imaging system.

[0003] Traditionally, after moving the phantom to the center of the field of view (FOV), the phantom is scanned from multiple angles to determine whether it is in the desired position.

[0004] However, traditional phantom positioning methods suffer from low positioning efficiency. Summary of the Invention

[0005] Therefore, it is necessary to provide a method, apparatus, computer equipment, computer-readable storage medium, and computer program product that can improve the positioning efficiency of the phantom, addressing the aforementioned technical problems.

[0006] In a first aspect, this application provides a phantom positioning method, wherein the phantom is provided with at least one set of positioning ball pairs, each set of positioning ball pairs including two positioning balls, the two positioning balls in the positioning ball pair being respectively disposed on both sides of the central surface of the phantom, and the distance between them and the central surface is equal; the central surface of the phantom is parallel to the central surface of the detector; the method includes:

[0007] Obtain the original scan image of the phantom at its initial position;

[0008] Based on the original scanned image and the position information of the detector's central surface, the distance difference between the two positioning balls in the positioning ball pair and the detector's central surface is determined.

[0009] The movement information of the model is determined based on the distance difference, and the model is positioned and adjusted according to the movement information.

[0010] In one embodiment, determining the distance difference between the two positioning balls in the positioning ball pair and the center plane of the detector, based on the original scanned image and the position information of the detector's central surface, includes:

[0011] The projected position coordinates of the two positioning balls in the positioning ball pair are determined based on the original scanned image;

[0012] Based on the projected position coordinates of the two positioning balls in the positioning ball pair and the position information of the detector's center surface, determine the distances between the two positioning balls in the positioning ball pair and the detector's center surface.

[0013] The distance difference is determined based on the distances between the two positioning balls in the positioning ball pair and the center plane of the detector.

[0014] In one embodiment, determining the distances between the two positioning balls in the positioning ball pair and the center surface of the detector, based on the projected position coordinates of the two positioning balls in the positioning ball pair and the position information of the detector's center surface, includes:

[0015] For each positioning ball in the positioning ball pair, the initial distance between the positioning ball and the center surface of the detector is determined based on the position information of the preset coordinate axis in the projected position coordinates of the positioning ball and the position information of the center surface of the detector.

[0016] The distance between the positioning ball and the center plane of the detector is determined based on the initial distance, the pixel size of the detector, and the system magnification ratio.

[0017] In one embodiment, determining the movement information of the phantom based on the distance difference includes:

[0018] The position of the mold is determined and the distance is adjusted based on the distance difference;

[0019] If the absolute value of the position adjustment distance is greater than or equal to the preset adjustment distance threshold, the movement information of the model is determined based on the position adjustment distance; the movement information includes the movement direction and the movement distance.

[0020] If the absolute value of the position adjustment distance is less than the preset adjustment distance threshold, then there is no need to adjust the positioning of the model.

[0021] In one embodiment, the distance difference is the difference between the distance between the second positioning ball and the center plane of the detector in the positioning ball pair and the distance between the first positioning ball and the center plane of the detector, wherein the first and second positioning balls are arranged along the retraction direction of the scanning bed; the movement information of the phantom is determined by adjusting the distance according to the position, including:

[0022] If the position adjustment distance is less than zero, the direction of mold movement is the retraction direction, and the distance of mold movement is the absolute value of the position adjustment distance;

[0023] If the position adjustment distance is greater than zero, the direction of mold movement is the bed feed direction, and the distance of mold movement is the position adjustment distance.

[0024] In one embodiment, the method further includes:

[0025] Multi-angle image scanning of the phantom is performed to obtain scanned images of the phantom from multiple angles;

[0026] If all the positioning ball pairs on the phantom are included in the scan images from multiple angles, then the step of determining the distance difference between the two positioning balls in the positioning ball pair and the center plane of the detector is performed based on the original scan images and the position information of the detector's center plane.

[0027] Secondly, this application also provides a phantom positioning device, characterized in that at least one set of positioning ball pairs is provided on the phantom, each set of positioning ball pairs includes two positioning balls, the two positioning balls in the positioning ball pair are respectively disposed on both sides of the central surface of the phantom, and the distance between them and the central surface is equal; the central surface of the phantom is parallel to the central surface of the detector; the device includes:

[0028] The acquisition module is used to acquire the original scanned image of the phantom at its initial position;

[0029] The determination module is used to determine the distance difference between the two positioning balls in the positioning ball pair and the center plane of the detector, based on the original scanned image and the position information of the detector's center plane.

[0030] The positioning module is used to determine the movement information of the model based on the distance difference, and to adjust the positioning of the model based on the movement information.

[0031] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the phantom positioning method in the first aspect described above.

[0032] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the phantom positioning method in the first aspect described above.

[0033] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the phantom positioning method in the first aspect described above.

[0034] The aforementioned phantom positioning method, apparatus, computer equipment, storage medium, and computer program product include a phantom for calibrating medical imaging equipment with at least one set of positioning ball pairs. Each pair of positioning balls includes two positioning balls, which are respectively positioned on opposite sides of the central surface of the phantom and are equidistant from the central surface. The central surface of the phantom is parallel to the central surface of the detector. Based on this, the medical imaging equipment can acquire the original scan image of the phantom at its initial position and determine the distance difference between the two positioning balls in the positioning ball pair and the central surface of the detector based on the original scan image and the position information of the central surface of the detector. Furthermore, the movement information of the phantom is determined based on the distance difference, and the phantom is positioned and adjusted according to the movement information. In other words, by using the method proposed in this application embodiment, only one original scan image of the phantom in its initial position needs to be acquired. Based on the original scan image and the position information of the detector's center surface, the distance difference between the two positioning balls supporting the phantom and the center surface of the detector relative to the phantom's center surface can be determined. Thus, the phantom can be positioned and adjusted based on this distance difference. There is no need to scan the phantom from multiple angles or even the entire circle. Data acquisition is convenient and fast, which not only improves data acquisition efficiency and thus improves phantom positioning efficiency, but also enables automatic positioning adjustment of the phantom, thereby improving the efficiency and accuracy of phantom positioning adjustment. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a diagram illustrating the application environment of the phantom positioning method in one embodiment;

[0037] Figure 2(a) is a schematic diagram of the structure of the center surface of the mold in one embodiment;

[0038] Figure 2(b) is a schematic diagram of the structure of the central surface of the mold in another embodiment;

[0039] Figure 3 This is a flowchart illustrating a phantom positioning method in one embodiment;

[0040] Figure 4 This is a flowchart illustrating the phantom positioning method in another embodiment;

[0041] Figure 5 This is a flowchart illustrating the phantom positioning method in another embodiment;

[0042] Figure 6 This is a flowchart illustrating the phantom positioning method in another embodiment;

[0043] Figure 7 This is a flowchart illustrating the phantom positioning method in another embodiment;

[0044] Figure 8 This is a schematic diagram of the complete process of the phantom positioning method in one embodiment;

[0045] Figure 9 This is a structural block diagram of the phantom positioning device in one embodiment;

[0046] Figure 10 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0048] Computed Tomography (CT) is a commonly used imaging technology in the medical field. In order to ensure the accuracy of CT imaging system scanning, it is often necessary to use a geometric correction phantom to correct the CT imaging system. When performing correction, the first thing to do is to ensure that the geometric correction phantom is located at the center of the field of view (FOV) of the CT imaging system, that is, the center plane of the geometric correction phantom is completely coincident with the center plane of the detector.

[0049] Traditionally, after moving the phantom to the center of the field of view (FOV), errors may exist in the actual manufacturing process of the geometric correction phantom, and errors may also exist in the assembly process of the CT system and the scanning bed's motion mechanism. Therefore, it is impossible to guarantee that the center plane of the geometric correction phantom will coincide with the center plane of the detector in the system. Thus, the position of the geometric correction phantom needs to be adjusted. Typically, image data of the phantom can be scanned around its perimeter, and the phantom can be subjectively judged to determine whether it is in the desired position. Alternatively, positioning images of the phantom can be scanned from multiple angles to subjectively determine whether it is in the desired position.

[0050] However, traditional phantom positioning methods have low positioning efficiency and low accuracy based on subjective judgment.

[0051] Based on this, this application proposes a phantom positioning method that can achieve precise positioning of a geometric correction phantom through image scanning at one angle, and realize automatic calculation and adjustment of the position of the geometric correction phantom under different scanning FOVs, thereby improving the positioning efficiency and accuracy of the phantom.

[0052] The phantom positioning method provided in this application embodiment can be applied to, for example... Figure 1 The application environment shown. Among them, the medical imaging equipment 102 may include, but is not limited to, any medical imaging equipment that performs medical imaging based on X-rays, such as: computed tomography (CT) equipment, positron emission tomography-computed tomography (PET-CT) equipment, etc.

[0053] When performing system calibration on such medical imaging equipment 102, a calibration phantom matching the calibration can be used and placed at a preset position on the scanning bed of the medical imaging equipment 102. By moving the scanning bed, the calibration phantom can be moved into the field of view (FOV) of the medical imaging equipment 102, so that the center plane of the calibration phantom coincides with the center plane of the detector in the medical imaging equipment 102.

[0054] For example, the correction mold (hereinafter referred to as the mold) may be provided with at least one set of positioning ball pairs. Each set of positioning ball pairs includes two positioning balls. The two positioning balls in the positioning ball pair are respectively arranged on both sides of the central surface of the mold and the distance between them and the central surface is equal. The two positioning balls in a set of positioning ball pairs may be arranged symmetrically along the central surface of the mold or asymmetrically along the central surface of the mold. It is only necessary to ensure that the vertical distance between the two positioning balls on both sides of the central surface of the mold and the central surface is equal.

[0055] For example, the mold body can be a cylindrical structure, such as a solid cylinder or a hollow cylinder. The central surface of the mold body can be a plane passing through the central axis of the cylinder, as shown in Figure 2(a), or it can be a plane parallel to the bottom surface of the cylinder and passing through the center line of the cylinder's height, as shown in Figure 2(b). Based on this, multiple positioning balls can be set on both sides of the central surface of the mold body. Two positioning balls with equal vertical distances from the central surface on both sides form a pair of positioning balls. For example, positioning ball 1 and positioning ball 6 form a pair of positioning balls, positioning ball 2 and positioning ball 5 form a pair of positioning balls, positioning ball 3 and positioning ball 4 form a pair of positioning balls, etc.

[0056] It should be noted that when the mold body is a cylinder, there can be multiple planes passing through the central axis of the cylinder. When setting the positioning ball pairs based on the central plane, multiple sets of positioning ball pairs can be set at equal intervals along the side curved surface of the cylinder.

[0057] In one exemplary embodiment, such as Figure 3 As shown, a phantom positioning method is provided, which can be applied to... Figure 1Taking medical imaging equipment as an example, the explanation includes the following steps 302 to 306. Wherein:

[0058] Step 302: Obtain the original scan image of the phantom at the initial position.

[0059] The initial position can be the position of the phantom within the FOV scanning field of view of the medical imaging equipment, determined by the phantom's size parameters and the equipment's system parameters. The system parameters of the medical imaging equipment may include, but are not limited to, the phantom's position on the scanning bed, the relevant parameters of the scanning bed's motion mechanism, and the relevant parameters of the scanning protocol.

[0060] For example, a user can place the phantom on the scanning bed of a medical imaging device and control the scanning bed to move the phantom to the initial position of the medical imaging device, that is, the theoretical position where the center plane of the phantom coincides with the center plane of the detector of the medical imaging device. It should be noted that when placing the phantom on the scanning bed, the center plane of the phantom must be placed parallel to the center plane of the detector. If the center plane of the phantom is as shown in Figure 2(a) above, the phantom can be placed vertically along its axial direction, that is, the cylinder can be placed upright on the scanning bed, or the phantom can be placed parallel along its axial direction, that is, the cylinder can be placed horizontally on the scanning bed, and the axial direction of the cylinder is parallel to the center plane of the detector. If the center plane of the phantom is as shown in Figure 2(b) above, the cylinder can be placed horizontally on the scanning bed, and the axial direction of the cylinder is perpendicular to the center plane of the detector.

[0061] Based on this, the medical imaging equipment can determine the movement information of the scanning bed according to the size parameters of the phantom and the system parameters of the medical imaging equipment. Then, according to the movement information of the scanning bed, the scanning bed is controlled to move to the initial position. At the initial position, the medical imaging equipment performs image scanning on the phantom on the scanning bed, thereby obtaining the original scan image of the phantom at the initial position.

[0062] For example, the original scanned image can be a raw data image of the phantom, that is, an image generated based on the scanned raw data of the phantom. The scanned raw data can be data directly collected by the detector, such as the number of photons per pixel collected by the photon detector. Of course, the original scanned image can also be other types of images, such as scan reconstructed images, etc. This application embodiment does not specifically limit this.

[0063] For example, when scanning a phantom, the image can be scanned at any angle, such as 0°, 30°, 90°, etc., and this application embodiment does not specifically limit this. Here, 0° means that the X-ray tube of the medical imaging equipment is directly above the scanning bed, and the detector is directly below the scanning bed; that is, the X-ray tube and the detector are in the vertical direction, with the X-ray tube located above the vertical direction and the detector located below the vertical direction. In this example, the phantom can be scanned at any angle to obtain the original scanned image of the phantom at that angle, which is a two-dimensional image at that angle.

[0064] It should be noted that the phantom can be placed on the scanning bed or on top of the scanning bed. The phantom is fixed by the mounting components on the top and moved into the FOV scanning field of view of the medical imaging equipment by moving the scanning bed (advancing / retracting).

[0065] Step 304: Based on the original scanned image and the position information of the detector's center plane, determine the distance difference between the two positioning balls in the positioning ball pair and the detector's center plane.

[0066] For example, when multiple sets of positioning ball pairs are provided in the phantom, the positioning adjustment of the phantom can be performed based on one or more sets of positioning ball pairs. Taking a set of positioning ball pairs as an example, such as positioning ball 3 and positioning ball 4, when the original scan image of the phantom is obtained by scanning, the position information of positioning ball 3 and the position information of positioning ball 4 can be determined based on the original scan image. Combined with the position information of the center surface of the detector, the vertical distance between positioning ball 3 and the center surface of the detector, and the vertical distance between positioning ball 4 and the center surface of the detector can be determined respectively. Then, based on the vertical distance between positioning ball 3 and the center surface of the detector and the vertical distance between positioning ball 4 and the center surface of the detector, the distance difference between positioning ball 3, positioning ball 4 and the center surface of the detector can be determined.

[0067] When the distance difference between positioning ball 3 and positioning ball 4 and the center plane of the detector is 0, it indicates that the vertical distance between positioning ball 3 and the center plane of the detector and the vertical distance between positioning ball 4 and the center plane of the detector are equal. Since positioning ball 3 and positioning ball 4 are symmetrical about the center plane of the phantom, that is, the vertical distance between positioning ball 3 and the center plane of the phantom and the vertical distance between positioning ball 4 and the center plane of the phantom are equal, it can be determined that the center plane of the phantom coincides with the center plane of the detector. This indicates that the phantom is already located in the center of the FOV of the medical imaging equipment in the initial position and meets the position requirements for subsequent medical imaging equipment calibration. In this case, it is not necessary to perform a positioning adjustment operation on the phantom.

[0068] Conversely, when the distance difference between positioning ball 3 and positioning ball 4 and the center surface of the detector is not 0, it means that the center surface of the phantom does not coincide with the center surface of the detector. In this case, the phantom needs to be positioned and adjusted so that the center surface of the phantom and the center surface of the detector are completely coincident.

[0069] For example, in the case of multiple sets of positioning ball pairs, the medical imaging equipment can determine the distance difference between at least two sets of positioning ball pairs and the center plane of the detector. Taking the phantom shown in Figure 2(a) as an example, if the distance difference between the two sets of positioning ball pairs and the center plane of the detector is the same, it indicates that the center plane of the phantom and the center plane of the detector are parallel to each other. If the distance difference is not zero, the phantom only needs to be moved along the in / out direction of the scanning bed to align the center plane of the phantom with the center plane of the detector. However, if the distance difference between the two sets of positioning ball pairs and the center plane of the detector is different, it indicates that... When the center plane of the phantom is tilted relative to the center plane of the detector, it is necessary not only to move the phantom along the advance / retreat direction of the scanning bed, but also to adjust the phantom's attitude. For example, the user can be prompted to manually adjust the phantom's attitude, or an attitude adjustment component can be installed on the scanning bed to adjust the phantom's attitude. By controlling this attitude adjustment component, the phantom's attitude can be automatically adjusted so that the center plane of the adjusted phantom is parallel to the center plane of the detector. At the same time, the advance or retreat of the scanning bed can be controlled to make the center plane of the phantom completely coincide with the center plane of the detector.

[0070] Step 306: Determine the movement information of the model based on the distance difference, and adjust the positioning of the model based on the movement information.

[0071] The movement information of the phantom can include parallel movement information and / or rotational movement information. When the center plane of the phantom is parallel to the center plane of the detector and the distance difference is not zero, the movement information of the phantom can include parallel movement information, which can include the movement direction and movement distance. When the center plane of the phantom is not parallel to the center plane of the detector and there is a distance difference of zero, the movement information of the phantom can include rotational movement information, which can include the rotation direction and rotation angle. When the center plane of the phantom is not parallel to the center plane of the detector and all distance differences are not zero, the movement information of the phantom can include both parallel movement information and rotational movement information.

[0072] For example, when the distance difference between a pair of positioning balls and the center plane of the detector is determined, the parallel movement information of the phantom can be determined based on this distance difference. Taking positioning balls 3 and 4 as examples, when the vertical distance between positioning ball 3 and the center plane of the detector is greater than the vertical distance between positioning ball 4 and the center plane of the detector, it indicates that positioning ball 4 is closer to the center plane of the detector. In this case, the scanning bed should be controlled to move the phantom along the direction from positioning ball 3 to positioning ball 4, that is, move positioning ball 3 towards the center plane of the detector, and move positioning ball 4 away from the center plane of the detector. Conversely, when the vertical distance between positioning ball 3 and the center plane of the detector is less than the vertical distance between positioning ball 4 and the center plane of the detector, it indicates that positioning ball 3 is closer to the center plane of the detector. In this case, the scanning bed should be controlled to move the phantom along the direction from positioning ball 4 to positioning ball 3, that is, move positioning ball 3 away from the center plane of the detector, and move positioning ball 4 towards the center plane of the detector. The moving distance is half of the distance difference between positioning balls 3 and 4 and the center plane of the detector.

[0073] For example, when the distance difference between two or more positioning ball pairs and the center plane of the detector is determined, it can be first determined whether the center plane of the phantom and the center plane of the detector are parallel based on the distance difference between multiple sets of positioning ball pairs and the center plane of the detector. If they are parallel, the parallel movement information of the phantom can be determined based on the distance difference between any set of positioning ball pairs and the center plane of the detector. If they are not parallel, the rotational movement information of the phantom can be determined based on the distance difference between any two sets of positioning ball pairs and the center plane of the detector, so that the center plane of the phantom and the center plane of the detector remain parallel. Then, the parallel movement information of the phantom is determined based on the distance difference between the positioning ball pairs and the center plane of the detector in the parallel state, so as to control the rotation of the phantom based on the rotational movement information of the phantom, and then control the translation of the phantom based on the parallel movement information of the phantom, so that the center plane of the phantom and the center plane of the detector are completely coincident.

[0074] For example, the medical imaging device can output rotational movement information and / or parallel movement information of the phantom to the user, thereby instructing the user to manually position and adjust the phantom; of course, the medical imaging device can also control the scanning bed or the posture adjustment component on the scanning bed to rotate the phantom based on the rotational movement information of the phantom, and control the scanning bed to perform bed entry / exit operations based on the parallel movement information of the phantom, so as to translate the phantom so that the center plane of the phantom is completely aligned with the center plane of the detector.

[0075] In the above-described phantom positioning method, the phantom used for medical imaging equipment calibration is provided with at least one set of positioning ball pairs. Each set of positioning ball pairs includes two positioning balls, which are respectively positioned on both sides of the central surface of the phantom and are equidistant from the central surface. The central surface of the phantom is parallel to the central surface of the detector. Based on this, the medical imaging equipment can acquire the original scan image of the phantom at its initial position and determine the distance difference between the two positioning balls in the positioning ball pair and the central surface of the detector based on the original scan image and the position information of the central surface of the detector. Then, the movement information of the phantom is determined according to the distance difference, and the phantom is positioned and adjusted according to the movement information of the phantom. In other words, by using the method proposed in this application embodiment, only one original scan image of the phantom in its initial position needs to be acquired. Based on the original scan image and the position information of the detector's center surface, the distance difference between the two positioning balls supporting the phantom and the center surface of the detector relative to the phantom's center surface can be determined. Thus, the phantom can be positioned and adjusted based on this distance difference. There is no need to scan the phantom from multiple angles or even the entire circle. Data acquisition is convenient and fast, which not only improves data acquisition efficiency and thus improves phantom positioning efficiency, but also enables automatic positioning adjustment of the phantom, thereby improving the efficiency and accuracy of phantom positioning adjustment.

[0076] In one exemplary embodiment, such as Figure 4 As shown, step 304 above may include steps 402 to 406. Wherein:

[0077] Step 402: Determine the projected position coordinates of the two positioning balls in the positioning ball pair based on the original scanned image.

[0078] For example, a medical imaging device can calculate the projection value of each pixel in the original scanned image to obtain a projected image corresponding to the original scanned image. Then, it can identify positioning spheres in the projected image to obtain the projected position coordinates of the two positioning spheres in each pair. Here, the projection value refers to the projection data after the X-rays have been attenuated by different objects, and the projected position coordinates of the positioning spheres can be the position coordinates of the center point of the positioning spheres in the projected image.

[0079] For example, when calculating the projection value of a pixel, the following projection value calculation formula (1) can be used to obtain the projection value of the pixel.

[0080] (1)

[0081] Where i and j represent pixel indices, and air represents the raw X-ray scan image taken without the phantom placed, which is obtained through the air. This represents the pixel value of pixel (i,j) in the original scan image corresponding to the air, and obj represents the original scan image of X-rays passing through the phantom when the phantom was placed. This represents the pixel value of pixel (i,j) in the original scanned image corresponding to the phantom. This represents the projected value of pixel (i,j).

[0082] It should be noted that the original scan image corresponding to the air and the original scan image corresponding to the phantom can be scan images at the same scanning angle or scan images at different scanning angles. In addition, the above projection value calculation method is only used as an example for illustration. In actual applications, other projection conversion methods or projection calculation methods can also be used to determine the projection position coordinates of the positioning ball. This application embodiment does not make specific limitations on this.

[0083] Step 404: Determine the distances between the two positioning balls in the positioning ball pair and the center surface of the detector based on the projected position coordinates of the two positioning balls in the positioning ball pair and the position information of the center surface of the detector.

[0084] The position information of the detector's center surface can be calculated based on the detector's size, specifically determined by the number of rows of the detector. For example, half of the number of rows of the detector can be used as the position information of the detector's center surface, where the number of rows of the detector is the number of pixels of the detector in the Z-axis direction of the medical imaging equipment.

[0085] For example, taking the X-ray tube at a scanning angle of 0° as an example, the original scanning image of the phantom can be a two-dimensional planar image under the XZ coordinate plane of the medical imaging equipment. After the original scanning image of the phantom is projected and transformed, a two-dimensional projected image under the XZ coordinate plane can be obtained. That is, the projected position coordinates of the two positioning balls in the positioning ball pair can be two-dimensional position coordinates under the XZ coordinate plane. Based on this, when adjusting the phantom positioning, the distance between the two positioning balls in the positioning ball pair and the center plane of the detector can be determined based on the Z-axis position information in the projected position coordinates of the two positioning balls in the positioning ball pair and the position information of the center plane of the detector.

[0086] In other words, taking positioning spheres 3 and 4 as examples, the Z-axis position information Z3 in the projected position coordinates of positioning sphere 3 and the position information Z of the detector's center plane can be used as a reference. mid Determine the distance ΔZ3 between the positioning sphere 3 and the center plane of the detector; and determine the Z-axis position information Z4 in the projected position coordinates of the positioning sphere 4 and the position information Z of the center plane of the detector. mid Determine the distance △Z4 between the positioning ball 4 and the center plane of the detector.

[0087] Similarly, using the above method, the distance between each positioning ball in other positioning ball pairs and the center plane of the detector can be determined.

[0088] Step 406: Determine the distance difference based on the distances between the two positioning balls in the positioning ball pair and the center surface of the detector.

[0089] For example, the difference between the distances between the two positioning balls in the positioning ball pair and the center surface of the detector can be used as the distance difference between the positioning ball pair and the center surface of the detector; alternatively, the absolute value of the difference between the distances between the two positioning balls in the positioning ball pair and the center surface of the detector can be used as the distance difference between the positioning ball pair and the center surface of the detector.

[0090] In this embodiment, when determining the distance difference between the two positioning balls in the positioning ball pair and the center plane of the detector based on the original scanned image, the original scanned image can first be transformed by projection to obtain the projected position coordinates of the two positioning balls in the positioning ball pair. Then, based on the projected position coordinates of the two positioning balls in the positioning ball pair and the position information of the center plane of the detector, the distance difference between the two positioning balls in the positioning ball pair and the center plane of the detector is determined. Using this method, the distance difference between the positioning ball pair and the center plane of the detector can be calculated, improving the accuracy of the distance difference calculation.

[0091] In one exemplary embodiment, such as Figure 5 As shown, step 404 above may include steps 502 to 504. Wherein:

[0092] Step 502: For each positioning ball in the positioning ball pair, determine the initial distance between the positioning ball and the center surface of the detector based on the position information of the preset coordinate axis in the projected position coordinates of the positioning ball and the position information of the center surface of the detector.

[0093] The preset coordinate axis can be the Z-axis of the coordinate system of the medical imaging equipment, that is, the row direction of the detector.

[0094] For example, for each positioning ball in the positioning ball pair, the initial distance between the positioning ball and the center surface of the detector can be determined based on the Z-axis position information in the projection position coordinates of the positioning ball and the position information of the center surface of the detector. Taking a scanning angle of 0° as an example, the original scanning image of the phantom is a two-dimensional planar image under the XZ coordinate plane of the medical imaging device. The coordinate system of the original scanning image takes the pixel at the upper left corner of the original scanning image as the origin, the horizontal coordinate is the X direction, and the vertical coordinate is the Z direction. When the positioning balls in the phantom are sequentially numbered according to the Z direction, for positioning ball 3 and positioning ball 4, positioning ball 3 is located above the center line of the detector, and the Z-axis coordinate of positioning ball 3 is less than the Z-axis coordinate of the center line of the detector. Positioning ball 4 is located below the center line of the detector, and the Z-axis coordinate of positioning ball 4 is greater than the Z-axis coordinate of the center line of the detector.

[0095] Based on this, when calculating the initial distance between the positioning ball 3 and the center plane of the detector, the position information Z of the center plane of the detector can be used. mid The difference between the Z-axis position information Z3 of positioning ball 3 and the position information Z3 of positioning ball 3 is used as the initial distance ΔZ between positioning ball 3 and the center plane of the detector. 3,0 That is, △Z 3,0 =Z mid -Z3.

[0096] When calculating the initial distance between the positioning sphere 4 and the center plane of the detector, the Z-axis position information Z4 of the positioning sphere 3 and the position information Z of the center plane of the detector can be used. mid The difference is used as the initial distance △Z between the positioning sphere 4 and the center plane of the detector. 4,0 That is, △Z 4,0 =Z4-Z mid .

[0097] Step 504: Determine the distance between the positioning ball and the center plane of the detector based on the initial distance, the pixel size of the detector, and the system magnification ratio.

[0098] The pixel size of the detector can be the pixel size of the detector on a preset coordinate axis, that is, the pixel size of the detector in the Z-axis direction; the system magnification ratio is the magnification ratio corresponding to the medical imaging equipment when performing image scanning. Different system magnification ratios can be used for image scanning in different image scanning or scanning protocols; the system magnification ratio can be expressed as the quotient of the distance from the X-ray tube focal point to the detector and the distance from the X-ray tube focal point to the rotation axis of the image scanning.

[0099] For example, given the initial distance between the positioning ball and the center plane of the detector, the distance between them can be determined by multiplying the initial distance by the pixel size of the detector on a preset coordinate axis, and then dividing the product by the system magnification ratio. For instance, for positioning ball 3, the distance ΔZ3 between positioning ball 3 and the center plane of the detector can be expressed as:

[0100] △Z3=△Z 3,0 *fDetV / M=(Z mid -Z3)*fDetV / M (2)

[0101] For positioning sphere 4, the distance ΔZ4 between positioning sphere 4 and the center plane of the detector can be expressed as:

[0102] △Z4=△Z 4,0 *fDetV / M=(Z4-Z mid )*fDetV / M (3)

[0103] Where fDetV is the pixel size of the detector on the preset coordinate axis, and M is the system magnification ratio.

[0104] Based on this, when calculating the distance difference between positioning spheres 3 and 4 and the central surface of the detector, the difference between the distance between positioning sphere 4 and the central surface of the detector and the distance between positioning sphere 3 and the central surface of the detector can be taken as the distance difference between the positioning sphere pair and the central surface of the detector, i.e., the distance difference Δ = ΔZ4 - ΔZ3. At this time, when the distance between positioning sphere 3 and the central surface of the detector is greater than the distance between positioning sphere 4 and the central surface of the detector, the distance difference Δ < 0; when the distance between positioning sphere 3 and the central surface of the detector is less than the distance between positioning sphere 4 and the central surface of the detector, the distance difference Δ > 0; when the distance between positioning sphere 3 and the central surface of the detector is equal to the distance between positioning sphere 4 and the central surface of the detector, the distance difference Δ = 0.

[0105] In this embodiment, after determining the initial distance between the positioning ball and the center surface of the detector in the image dimension based on the original scanned image, the actual distance between the positioning ball and the center surface of the detector is calculated by further combining the pixel size of the detector on the preset coordinate axis and the system magnification ratio, so as to perform subsequent phantom positioning adjustment based on the actual distance and improve the accuracy of phantom positioning adjustment.

[0106] In one exemplary embodiment, such as Figure 6 As shown, step 306 above, "determining the movement information of the model based on the distance difference," may include steps 602 to 606. Wherein:

[0107] Step 602: Determine the position adjustment distance of the mold based on the distance difference.

[0108] The position adjustment distance can be expressed as the movement distance of the mold body. When the movement of the mold body is controlled by the movement of the scanning bed, the position adjustment distance can also be expressed as the movement distance of the scanning bed, such as the movement distance of the scanning bed in the Z-axis direction.

[0109] For example, when the distance difference between the two positioning balls in the positioning ball pair and the center plane of the detector is determined, half of the distance difference can be used as the position adjustment distance of the phantom, that is, the position adjustment distance d = distance difference Δ / 2.

[0110] Step 604: If the absolute value of the position adjustment distance is greater than or equal to the preset adjustment distance threshold, then determine the movement information of the model based on the position adjustment distance; the movement information includes the movement direction and the movement distance.

[0111] The preset adjustment distance threshold can be the pixel size of the detector on the preset coordinate axis, or it can be greater than or less than the pixel size of the detector on the preset coordinate axis.

[0112] When the absolute value of the position adjustment distance is greater than or equal to the preset adjustment distance threshold, it indicates that the distance between the center plane of the phantom and the center plane of the detector is too far, which will have a significant impact on the subsequent system calibration of medical imaging equipment, resulting in a large calibration error. Therefore, the movement of the phantom can be controlled according to the position adjustment distance.

[0113] For example, when the distance difference is the difference between the distance between the second positioning ball and the center surface of the detector and the distance between the first positioning ball and the center surface of the detector, wherein the first positioning ball and the second positioning ball are arranged along the retraction direction of the scanning bed, such as the first positioning ball being positioning ball 3 and the second positioning ball being positioning ball 4, if the position adjustment distance is less than zero, it means that the distance between positioning ball 3 and the center surface of the detector is greater than the distance between positioning ball 4 and the center surface of the detector, and positioning ball 4 is closer to the center surface of the detector. Then, the movement direction of the phantom is the retraction direction, even if positioning ball 3 is closer to the center surface of the detector and positioning ball 4 is farther away from the center surface of the detector, and the movement distance of the phantom is the absolute value of the position adjustment distance.

[0114] If the position adjustment distance is greater than zero, it means that the distance between the positioning ball 3 and the center surface of the detector is less than the distance between the positioning ball 4 and the center surface of the detector. The positioning ball 3 is closer to the center surface of the detector. Therefore, the movement direction of the model is the bed feeding direction. Even if the positioning ball 3 is far away from the center surface of the detector, the positioning ball 4 is close to the center surface of the detector, and the movement distance of the model is the position adjustment distance.

[0115] Step 606: If the absolute value of the position adjustment distance is less than the preset adjustment distance threshold, then there is no need to adjust the positioning of the model.

[0116] When the absolute value of the position adjustment distance is less than the preset adjustment distance threshold, it means that the center plane of the phantom is close to the center plane of the detector. The phantom in this position will not have a significant impact on the subsequent system calibration of the medical imaging equipment, and the system calibration error is also small. Therefore, there is no need to adjust the position of the phantom, and the subsequent system calibration operation of the medical imaging equipment can continue to be performed with the phantom in the current position.

[0117] In this embodiment, by setting a preset adjustment distance threshold, the position of the mold is adjusted when the absolute value of the position adjustment distance is greater than or equal to the preset adjustment distance threshold, and when the absolute value of the position adjustment distance is less than the preset adjustment distance threshold, the position of the mold does not need to be adjusted, thereby improving the efficiency and effectiveness of the mold positioning adjustment.

[0118] In one exemplary embodiment, such as Figure 7 As shown, the above method may further include:

[0119] Step 702: Perform multi-angle image scanning on the model to obtain scanned images of the model from multiple angles.

[0120] Step 704: If all the positioning ball pairs on the phantom are included in the scanned images from multiple angles, then the step in step 304 above, which determines the distance difference between the two positioning balls in the positioning ball pair and the center plane of the detector based on the position information of the original scanned image and the center plane of the detector, is executed.

[0121] The method proposed in the above embodiments of this application is mainly used for positioning and adjusting the phantom in the Z-axis direction, that is, ensuring that the center plane of the phantom coincides with the center plane of the detector. For the X-axis and Y-axis directions of the phantom, it is only necessary to ensure that the phantom is within the FOV scanning field of view of the medical imaging equipment. Therefore, before positioning and adjusting the phantom using the solution of this application, the phantom can be scanned from multiple angles to obtain scanned images of the phantom at multiple angles. The type of scanned image at each angle can be the same or different. In addition, the type of scanned image here can be the same or different from the type of the original scanned image mentioned above.

[0122] Next, positioning ball identification can be performed on the scanned images at each angle, and it can be determined whether all positioning ball pairs on the phantom are included in the scanned images at each angle, that is, whether all positioning balls on the phantom are included in the scanned images at each angle. If all positioning balls on the phantom are included in the scanned images at each angle, it can be said that the phantom is located within the FOV scanning field of view of the medical imaging equipment. Conversely, if at least one angle of the scanned image does not include all positioning balls on the phantom, it can be said that the phantom is significantly offset in the X or Y direction, and positioning adjustment in the X or Y direction is required. Alternatively, if the phantom is not located within the FOV scanning field of view of the medical imaging equipment, the user can be prompted to adjust the position and / or orientation of the phantom until the phantom is located within the FOV scanning field of view of the medical imaging equipment. Based on this, the phantom positioning method in any of the above embodiments can be used to adjust the positioning of the phantom in the Z direction, so that the center plane of the phantom is approximately coincident or completely coincident with the center plane of the detector.

[0123] In one exemplary embodiment, a complete process for phantom positioning and system calibration is provided, such as... Figure 8 As shown, it includes the following steps:

[0124] Step 1: After placing the phantom in the preset position on the scanning bed, control the scanning bed to move the phantom to the initial position according to the size parameters of the phantom and the system parameters of the medical imaging equipment.

[0125] The initial position is any position of the phantom within the FOV scanning field of view of the medical imaging equipment.

[0126] Step 2: Perform image scanning on the model at a preset scanning angle to obtain the original scanned image of the model at the initial position.

[0127] For example, in the initial position, the control device of the medical imaging equipment can send acquisition parameters to the medical imaging equipment, so that the medical imaging equipment can perform image scanning on the phantom based on the acquisition parameters to obtain the original scan image of the phantom in the initial position. The acquisition parameters can be image scanning parameters for positioning and adjusting the phantom, or image scanning parameters for subsequent system calibration. These acquisition parameters may include, but are not limited to, scanning parameters such as tube voltage (KV), current, filtration, electron beam, exposure time, resolution threshold, and the number of angles per single scan.

[0128] It should be noted that the acquisition parameters can also be sent before step 1, that is, the acquisition parameters are sent first, and then the positioning process of the model is executed.

[0129] For example, the original scanned image of the phantom can be a raw data image generated based on the raw data of X-rays after passing through the phantom collected by the detector; when the detector is a photon detector, the raw data collected by the detector can be the number of photons, and when the detector is another type of detector, the raw data collected by the detector can also be grayscale values.

[0130] Step 3: Based on the original scanned image, determine the projected position coordinates of two positioning balls in any one or more pairs of positioning balls on the phantom.

[0131] For example, the imaging process of a medical imaging device may include: data acquisition → data preprocessing → projection value calculation → data postprocessing → image reconstruction. After the detector acquires the raw scan data, the raw scan data (original scan image) can be preprocessed, including but not limited to averaging, bad pixel processing, cropping, and correction. Then, the preprocessed data is used to calculate the projection value, that is, the preprocessed original scan image is projected to obtain a projected image. Further, for the projected image, data postprocessing operations can be performed, including but not limited to various image corrections, such as attenuation correction and artifact correction. Finally, image reconstruction is performed based on the corrected image to obtain the reconstructed scan image, such as a two-dimensional tomographic image or a three-dimensional image.

[0132] In this example, once the projected image is obtained, the center coordinates of the two positioning balls in the positioning ball pair on the model can be determined based on the projected image, and these coordinates can be used as the projected position coordinates of the positioning balls.

[0133] Step 4: Determine the position adjustment distance based on the projected position coordinates of the two positioning balls in the positioning ball pair and the position information of the center surface of the detector.

[0134] The projected position coordinates of the positioning ball can be represented as (x... i ,z i ), where x i The z-coordinate represents the horizontal position coordinate. i Represents the longitudinal position coordinates; the position information Z of the detector's center plane. mid It can be represented as: Z mid =nSliceNum / 2, where nSliceNum represents the number of rows of the detector.

[0135] Taking positioning spheres 3 and 4 as examples, the distance from positioning sphere 3 to the center plane Z of the detector is... mid The distance is expressed as: △Z3=(Z mid -Z3)*fDetV / M, Positioning ball 4 to the center plane Z of the detector. mid The distance is expressed as: △Z4=(Z4-Z mid) *fDetV / M, where fDetV is the pixel size of the detector in the Z direction, M is the system magnification ratio, M = SDD / SID, SDD is the distance from the X-ray tube focal spot to the detector, and SID is the distance from the X-ray tube focal spot to the image scanning rotation axis.

[0136] The position adjustment distance d = (△Z4 - △Z3) / 2.

[0137] Step 5, if the absolute value of the position adjustment distance is greater than or equal to the preset adjustment distance threshold, determine the movement information of the phantom according to the position adjustment distance, and control the movement of the scanning bed's movement mechanism to perform positioning adjustment on the phantom according to the movement information of the phantom.

[0138] Among them, the preset adjustment distance threshold can be expressed as fThreshold. When |d| < fThreshold, no positioning adjustment of the phantom is required; when |d| ≥ fThreshold, if d < 0, it is necessary to reduce the bed code value of |d|, that is, control the scanning bed to move |d| bed code values along the bed withdrawal direction; if d > 0, it is necessary to increase the bed code value of d, that is, control the scanning bed to move d bed code values along the bed advancement direction.

[0139] Step 6, if the absolute value of the position adjustment distance is less than the preset adjustment distance threshold, no positioning adjustment of the phantom is required.

[0140] Step 7, after the position of the phantom meets the preset calibration conditions, perform data scanning for geometric parameter calibration, and then calculate geometric parameters based on the scanning data to achieve geometric parameter calibration of the medical imaging device; otherwise, re-execute Steps 1 to 7 to update the d value.

[0141] When using the above method to perform positioning adjustment on the phantom, it is not necessary to perform positioning image scanning at multiple angles. Only one-angle scanning is required to perform positioning adjustment operations on the geometric correction phantom. Data acquisition is convenient and efficient. After the acquisition parameters are issued, the correction phantom can be automatically adjusted to the desired position to perform geometric parameter calibration data acquisition and calculation.

[0142] It should be understood that although the steps in the flowcharts involved in the above-described embodiments are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-described embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or alternately with at least a part of other steps or steps or stages in other steps.

[0143] Based on the same inventive concept, this application also provides a phantom positioning device for implementing the phantom positioning method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more phantom positioning device embodiments provided below can be found in the limitations of the phantom positioning method described above, and will not be repeated here.

[0144] In one exemplary embodiment, such as Figure 9 As shown, a phantom positioning device is provided, wherein at least one set of positioning ball pairs is provided on the phantom, each set of positioning ball pairs includes two positioning balls, the two positioning balls in the positioning ball pair are respectively arranged on both sides of the central surface of the phantom, and the distance between them and the central surface is equal; the central surface of the phantom is parallel to the central surface of the detector; the device includes: an acquisition module 902, a determination module 904, and a positioning module 906, wherein:

[0145] The acquisition module 902 is used to acquire the original scanned image of the phantom at its initial position.

[0146] The determination module 904 is used to determine the distance difference between the two positioning balls in the positioning ball pair and the center plane of the detector based on the original scan image and the position information of the detector's center plane.

[0147] The positioning module 906 is used to determine the movement information of the model based on the distance difference, and to adjust the positioning of the model based on the movement information.

[0148] In one embodiment, the determining module 904 includes:

[0149] The first determining unit is used to determine the projected position coordinates of the two positioning balls in the positioning ball pair based on the original scanned image;

[0150] The second determining unit is used to determine the distances between the two positioning balls in the positioning ball pair and the center surface of the detector, based on the projected position coordinates of the two positioning balls in the positioning ball pair and the position information of the center surface of the detector.

[0151] The third determining unit is used to determine the distance difference based on the distances between the two positioning balls in the positioning ball pair and the center surface of the detector.

[0152] In one embodiment, the second determining unit is specifically used to determine, for each positioning ball in the positioning ball pair, the initial distance between the positioning ball and the center surface of the detector based on the position information of the preset coordinate axis in the projected position coordinates of the positioning ball and the position information of the center surface of the detector; and to determine the distance between the positioning ball and the center surface of the detector based on the initial distance, the pixel size of the detector and the system magnification ratio.

[0153] In one embodiment, the positioning module 906 includes:

[0154] The fourth determining unit is used to determine the position adjustment distance of the mold based on the distance difference;

[0155] The positioning unit is used to determine the movement information of the model based on the position adjustment distance when the absolute value of the position adjustment distance is greater than or equal to a preset adjustment distance threshold; the movement information includes the movement direction and the movement distance.

[0156] The positioning unit is also used to eliminate the need for positioning adjustment of the model when the absolute value of the position adjustment distance is less than a preset adjustment distance threshold.

[0157] In one embodiment, the distance difference is the difference between the distance between the second positioning ball and the center surface of the detector and the distance between the first positioning ball and the center surface of the detector in the positioning ball pair, wherein the first and second positioning balls are arranged along the retraction direction of the scanning bed; the positioning unit is used to move the phantom in the retraction direction when the position adjustment distance is less than zero, and the movement distance of the phantom is the absolute value of the position adjustment distance; and to move the phantom in the infeed direction when the position adjustment distance is greater than zero, and the movement distance of the phantom is the position adjustment distance.

[0158] In one embodiment, the device further includes:

[0159] The scanning module is used to perform multi-angle image scanning on the model, obtaining scanned images of the model from multiple angles;

[0160] The determination module 904 is used to perform the step of determining the distance difference between two positioning balls in a positioning ball pair and the center plane of the detector, based on the original scan image and the position information of the center plane of the detector, when all positioning ball pairs on the phantom are included in the scan images from multiple angles.

[0161] Each module in the aforementioned phantom positioning device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0162] In one exemplary embodiment, a computer device is provided. This computer device can be a medical imaging device or a control terminal communicatively connected to the medical imaging device. Taking the computer device as the control terminal as an example, its internal structure diagram can be as follows: Figure 10As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, Near Field Communication (NFC), or other technologies. When executed by the processor, the computer program implements a phantom positioning method. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0163] Those skilled in the art will understand that Figure 10 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0164] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the phantom positioning method in any of the above embodiments.

[0165] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the phantom positioning method in any of the above embodiments.

[0166] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of the phantom positioning method in any of the above embodiments.

[0167] It should be noted that the data involved in this application (including but not limited to data used for analysis, data stored, data displayed, etc.) are all data that have been fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0168] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0169] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0170] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for positioning a phantom, characterized in that, The phantom is provided with at least one set of positioning ball pairs, each set of positioning ball pairs including two positioning balls. The two positioning balls in the positioning ball pair are respectively located on both sides of the central surface of the phantom, and the distance between them and the central surface is equal; the central surface of the phantom is parallel to the central surface of the detector; the method includes: Obtain the original scan image of the phantom at its initial position; Based on the original scanned image and the position information of the detector's center plane, the distance difference between the two positioning balls in the positioning ball pair and the detector's center plane is determined. The movement information of the model is determined based on the distance difference, and the model is positioned and adjusted based on the movement information.

2. The method according to claim 1, characterized in that, The step of determining the distance difference between the two positioning balls in the positioning ball pair and the center plane of the detector based on the original scan image and the position information of the detector's center plane includes: The projected position coordinates of the two positioning balls in the positioning ball pair are determined based on the original scanned image; Based on the projected position coordinates of the two positioning balls in the positioning ball pair and the position information of the center surface of the detector, determine the distances between the two positioning balls in the positioning ball pair and the center surface of the detector; The distance difference is determined based on the distances between the two positioning balls in the positioning ball pair and the center surface of the detector.

3. The method according to claim 2, characterized in that, The step of determining the distances between the two positioning balls in the positioning ball pair and the center surface of the detector based on the projected position coordinates of the two positioning balls in the positioning ball pair and the position information of the center surface of the detector includes: For each positioning ball in the positioning ball pair, the initial distance between the positioning ball and the center surface of the detector is determined based on the position information of the preset coordinate axis in the projected position coordinates of the positioning ball and the position information of the center surface of the detector. The distance between the positioning ball and the center plane of the detector is determined based on the initial distance, the pixel size of the detector, and the system magnification ratio.

4. The method according to any one of claims 1-3, characterized in that, Determining the movement information of the phantom based on the distance difference includes: The position adjustment distance of the mold is determined based on the distance difference; If the absolute value of the position adjustment distance is greater than or equal to a preset adjustment distance threshold, then the movement information of the model is determined based on the position adjustment distance; the movement information includes the movement direction and the movement distance. If the absolute value of the position adjustment distance is less than the preset adjustment distance threshold, then there is no need to adjust the positioning of the model.

5. The method according to claim 4, characterized in that, The distance difference is the difference between the distance between the second positioning ball and the center surface of the detector and the distance between the first positioning ball and the center surface of the detector, wherein the first positioning ball and the second positioning ball are arranged along the retraction direction of the scanning bed; The step of adjusting the distance based on the position to determine the movement information of the phantom includes: If the position adjustment distance is less than zero, then the moving direction of the mold is the retraction direction, and the moving distance of the mold is the absolute value of the position adjustment distance; If the position adjustment distance is greater than zero, then the moving direction of the mold is the bed feeding direction, and the moving distance of the mold is the position adjustment distance.

6. The method according to any one of claims 1-3, characterized in that, The method further includes: The phantom is subjected to multi-angle image scanning to obtain scanned images of the phantom at the multiple angles; If all the scanning images from the multiple angles contain all the positioning ball pairs on the phantom, then the step of determining the distance difference between the two positioning balls in the positioning ball pair and the center surface of the detector based on the original scanning image and the position information of the center surface of the detector is performed.

7. A phantom positioning device, characterized in that, The phantom is provided with at least one set of positioning ball pairs, each set of positioning ball pairs including two positioning balls. The two positioning balls in the positioning ball pair are respectively located on both sides of the central surface of the phantom, and the distance between them and the central surface is equal. The central surface of the phantom is parallel to the central surface of the detector. The device includes: The acquisition module is used to acquire the original scanned image of the phantom at its initial position; The determining module is used to determine the distance difference between the two positioning balls in the positioning ball pair and the center surface of the detector based on the original scan image and the position information of the center surface of the detector; The positioning module is used to determine the movement information of the model based on the distance difference, and to adjust the positioning of the model based on the movement information of the model.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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