Sample bin offset determination method, apparatus, and computed tomography scanner

Abstract

The application provides a sample bin offset determination method and device and a computer tomography scanning equipment. The method comprises the following steps: obtaining a plurality of projection images of the sample bin when the sample bin is located on a preset bed; the plurality of projection images comprise a first projection image, a second projection image and a plurality of third projection images obtained by scanning the sample bin when the scanning equipment is located at a first angle, a second angle and a plurality of third angles, and the angle difference between the first angle and the second angle is 180°; determining a first offset and an offset angle of the sample bin based on the first projection image, the second projection image and the plurality of third projection images; and / or obtaining a plurality of local projection images of the sample bin when the scanning system is located at a preset angle; and determining a second offset of the sample bin based on the plurality of local projection images. The first offset and the second offset can be determined without reconstructing the first projection image, the second projection image and the third projection image, the determination efficiency of the sample bin offset is improved, and the service life of the scanning system is improved.

Description

Technical Field

[0001] This invention relates to the field of medical scanning equipment technology, specifically to a method, apparatus, and computed tomography (CT) scanning device for determining sample chamber offset. Background Technology

[0002] In scientific research fields such as biology and medicine, scanning systems often use sample chambers (animal chambers) to perform various scanning and imaging operations by placing samples inside the chamber. However, because sample chambers are generally large in length and width, placing samples at either end of the chamber, excessive sample weight, aging of the chamber material, or incorrect installation can all cause the chamber to deviate from the center of rotation of the scanning system. This results in sample chamber offset, leading to incomplete sample images, low spatial resolution, and other quality problems, ultimately rendering the scan invalid.

[0003] To improve the image quality obtained by scanning systems and avoid invalid scans, existing technologies propose using stepper motors to perform 360° scanning of the sample chamber. After obtaining the scan data, the data is reconstructed, and the offset of the sample chamber is determined based on the reconstructed image. However, existing technologies have the following technical problems: 1. The need to reconstruct the scan data to obtain a reconstructed image, based on which the offset can be determined, results in a complex calculation process and low efficiency in determining the sample chamber offset. 2. Using stepper motors to perform 360° scanning of the sample chamber leads to a longer exposure time for the scanning system, resulting in a shorter lifespan for the scanning system.

[0004] Therefore, there is an urgent need to provide a method, apparatus, and computed tomography (CT) scanning device for determining sample chamber offset, so as to improve the efficiency of sample chamber offset determination and extend the service life of the scanning system. Summary of the Invention

[0005] In view of this, it is necessary to provide a method, apparatus and computed tomography (CT) scanning device for determining sample chamber offset, so as to solve the technical problems of low efficiency in determining sample chamber offset and low service life of scanning system in the prior art.

[0006] On one hand, the present invention provides a method for determining the offset of a sample compartment, applied to a scanning system, the scanning system including a sample compartment and a scanning device for scanning the sample compartment, the method for determining the offset of the sample compartment including:

[0007] Multiple projection images are obtained when the sample compartment is located at a preset bed position; the multiple projection images include a first projection image, a second projection image, and multiple third projection images obtained by scanning the sample compartment when the scanning device is located at a first angle, a second angle, and multiple third angles, wherein the angle difference between the first angle and the second angle is 180°;

[0008] The first offset and offset angle of the sample compartment are determined based on the first projection map, the second projection map, and multiple third projection maps.

[0009] And / or,

[0010] The scanning system acquires multiple local projection images of the sample chamber when it is located at a preset angle; the multiple local projection images are projection images of each segment of the sample chamber when it is located at different bed positions;

[0011] The second offset of the sample compartment is determined based on the multiple local projection maps.

[0012] In some possible implementations, determining the first offset and offset angle of the sample bin based on the first projection map, the second projection map, and multiple third projection maps includes:

[0013] Determine the first center line of the first projection image, the second center line of the second projection image, and the multiple third center lines of the multiple third projection images;

[0014] The rotation centerline of the sample chamber is determined based on the first centerline and the second centerline;

[0015] The differences between the first centerline, the second centerline, the plurality of third centerlines and the rotation centerline are respectively used as the first angular offset component, the second angular offset component and the plurality of third angular offset components of the sample compartment when the scanning device is located at the first angle, the second angle and the plurality of third angles;

[0016] Based on a preset fitting model, the first angle offset component, the second angle offset component, and the plurality of third angle offset components are fitted to obtain the fitting component curve;

[0017] Determine the maximum offset in the fitted component curve and the corresponding angle of the maximum offset, and take the maximum offset as the first offset and the corresponding angle as the offset angle.

[0018] In some possible implementations, the first projection map includes at least one layer of first sub-projection map, the second projection map includes at least one layer of second sub-projection map, and each of the third projection maps includes at least one layer of third sub-projection map; determining the first center line of the first projection map, the second center line of the second projection map, and the plurality of third center lines of the plurality of third projection maps includes:

[0019] Determine the center coordinates of each layer of the first sub-projection map in the at least one layer of the first sub-projection map;

[0020] Determine the center coordinates of each layer of the second sub-projection map in the at least one layer of the second sub-projection map;

[0021] Determine the center coordinates of each layer of the third sub-projection map in the at least one layer of the third sub-projection map;

[0022] The line connecting the center coordinates of the first sub-projection map of each layer is taken as the first center line;

[0023] The line connecting the center coordinates of the second sub-projection maps of each layer is taken as the second center line;

[0024] The line connecting the center coordinates of the third sub-projection maps of each layer is taken as the third center line.

[0025] In some possible implementations, the number of layers in the at least one first sub-projection map is the same as the number of layers in the at least one second sub-projection map; determining the rotation centerline based on the first centerline and the second centerline includes:

[0026] The average of the center coordinates of the first sub-projection map of each layer and the center coordinates of the second sub-projection map of each layer corresponding to the first sub-projection map is used as the rotation center coordinates;

[0027] The line connecting the rotation center coordinates of the first sub-projection map and the second sub-projection map of each layer is taken as the rotation center line.

[0028] In some possible implementations, determining the second offset of the sample bin based on the plurality of local projection maps includes:

[0029] The second offset component of each segment of the local sample compartment is determined based on each of the local projection maps;

[0030] The sum of the second offset components is used as the second offset.

[0031] In some possible implementations, each of the local projection maps includes multiple layers of local sub-projection maps; determining the second offset component of the sample bin based on each of the local projection maps includes:

[0032] Obtain the projection offset of the local sub-projection maps of two adjacent layers;

[0033] The sum of the projection offsets is taken as the second offset component.

[0034] In some possible implementations, the sample bin offset determination method further includes:

[0035] Obtain the magnification ratio of the scanning device;

[0036] Data restoration processing is performed on the plurality of projection images and the plurality of partial projection images based on the magnification ratio.

[0037] In some possible implementations, the sample bin offset determination method further includes:

[0038] The sample bin is corrected based on the offset angle, the first offset, and / or the second offset.

[0039] On the other hand, the present invention also provides a sample compartment offset determination device, applied to a scanning system, the scanning system including a sample compartment and a scanning device for scanning the sample compartment, the sample compartment offset determination device comprising:

[0040] The projection image acquisition unit is used to acquire multiple projection images when the sample compartment is located at a preset bed position; the multiple projection images include a first projection image, a second projection image, and multiple third projection images obtained by scanning the sample compartment when the scanning device is located at a first angle, a second angle, and multiple third angles, wherein the angle difference between the first angle and the second angle is 180°;

[0041] The first offset determination unit is used to determine the first offset and offset angle of the sample compartment based on the first projection map, the second projection map and multiple third projection maps.

[0042] And / or,

[0043] The local projection image acquisition unit is used to acquire multiple local projection images of the sample chamber when the scanning system is located at a preset angle; the multiple local projection images are projection images of each segment of the local sample chamber when the sample chamber is located at different bed positions;

[0044] The second offset determination unit is used to determine the second offset of the sample compartment based on the plurality of local projection maps.

[0045] On the other hand, the present invention also provides a computed tomography (CT) scanning device, including a memory and a processor, wherein,

[0046] The memory is used to store programs;

[0047] The processor, coupled to the memory, is used to execute the program stored in the memory to implement the steps in the sample bin offset determination method described in any of the above possible implementations.

[0048] The beneficial effects of the above embodiments are as follows: The sample chamber offset determination method provided by the present invention first acquires multiple projection images of the sample chamber when it is located at a preset bed position. These multiple projection images include a first projection image, a second projection image, and multiple third projection images obtained by scanning the sample chamber when the scanning device is located at a first angle, a second angle, and multiple third angles. Then, based on the first projection image, the second projection image, and the multiple third projection images, the first offset and offset angle of the sample chamber are determined. This eliminates the need to reconstruct the first, second, and third projection images, thus reducing the computational burden of the reconstruction process and improving the efficiency of determining the first offset. Furthermore, the present invention acquires multiple local projection images of the sample chamber when the scanning system is located at a preset angle; these multiple local projection images are projection images of different segments of the sample chamber when it is located at different bed positions. Based on these multiple local projection images, the second offset of the sample chamber is determined. This also eliminates the need to reconstruct the local projection images, reducing the computational burden of the reconstruction process and improving the efficiency of determining the second offset. In other words, the efficiency of determining the three-dimensional spatial offset of the sample chamber is improved.

[0049] Furthermore, the present invention can obtain the first offset and / or the second offset simply by acquiring the first projection image, the second projection image, the third projection image and / or the partial projection image, without the need to acquire projection images at various angles, thereby reducing the exposure time of the scanning system, thereby reducing the aging degree of the scanning system and improving the service life of the scanning system. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 A schematic diagram of an embodiment of the scanning system provided by the present invention;

[0052] Figure 2 A schematic flowchart of an embodiment of the sample bin offset determination method provided by the present invention;

[0053] Figure 3 For the present invention Figure 2 A schematic diagram of an embodiment of S202;

[0054] Figure 4 A schematic diagram of an embodiment of the first and second projection diagrams provided by the present invention;

[0055] Figure 5 A schematic diagram of an embodiment of the fitting component curve provided by the present invention;

[0056] Figure 6 For the present invention Figure 3 A schematic diagram of an embodiment of S301;

[0057] Figure 7 For the present invention Figure 3 A schematic diagram of an embodiment of S302;

[0058] Figure 8 For the present invention Figure 2 A schematic diagram of an embodiment of S204;

[0059] Figure 9 A schematic diagram of an embodiment of the second offset component provided by the present invention;

[0060] Figure 10 For the present invention Figure 9 A schematic diagram of an embodiment of S901;

[0061] Figure 11 A schematic diagram of a process for eliminating the influence of amplification ratio provided by the present invention;

[0062] Figure 12 A schematic diagram of an embodiment of the sample bin offset determination device provided by the present invention;

[0063] Figure 13 This is a schematic diagram of an embodiment of the computed tomography (CT) scanning device provided by the present invention. Detailed Implementation

[0064] 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0065] It should be understood that the illustrative drawings are not drawn to scale. The flowcharts used in this invention illustrate operations implemented according to some embodiments of the invention. It should be understood that the operations in the flowcharts may be implemented out of order, and steps without logical contextual relationships may be reversed or performed simultaneously. Furthermore, those skilled in the art, guided by the content of this invention, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor systems and / or microcontroller systems.

[0066] In the description of the embodiments of the present invention, unless otherwise stated, "and / or" describes the relationship between associated objects, indicating that there can be three relationships, for example: A and / or B, which can represent three cases: A exists alone, A and B exist simultaneously, and B exists alone.

[0067] The terms "first," "second," etc., used in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a technical feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0068] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0069] This invention provides a method, apparatus, and computed tomography (CT) scanning device for determining sample chamber offset, which will be described below.

[0070] Before demonstrating the embodiments, the scanning system will be described first. For example... Figure 1 The diagram shown is a schematic representation of an embodiment of the scanning system provided by the present invention. The scanning system 10 includes an emitter 100 and a detector 200. A sample chamber is disposed between the emitter 100 and the detector 200. The emitter 100 emits rays perpendicular to the axis of the sample chamber. The detector 200 receives the transmitted rays emitted by the emitter 100 after they have passed through the sample chamber. The transmitted rays form a projection image of the sample chamber.

[0071] In some embodiments of the present invention, the scanning system 10 is a computed tomography (CT) system or a micro computed tomography (Micro-CT) system, and the radiation emitted by the transmitter 100 is X-rays.

[0072] The projection diagram is a two-dimensional diagram, and its coordinate system is a two-dimensional projective coordinate system, such as... Figure 1 As shown, the two-dimensional projected coordinate system includes the U-axis and V-axis, which represent the row and column directions of detector 200, respectively. The sample chamber is a three-dimensional entity, and its coordinate system is a three-dimensional spatial coordinate system, as shown below. Figure 1 As shown, the three-dimensional space includes the X-axis, Y-axis and Z-axis, with the Z-axis parallel to the U-axis, the Y-axis parallel to the V-axis, and the X-axis perpendicular to the Y-axis and Z-axis.

[0073] In some embodiments of the present invention, the angle of the scanning system 10 is the angle between the current position of the scanning system 10 and the initial position, wherein the initial position is the position where the transmitter 100 and the detector 200 are parallel to the Y-axis.

[0074] It should be understood that, since the length of the sample chamber is generally much longer than that of the detector 200, in order to obtain the complete sample chamber offset, in some embodiments of the present invention, such as... Figure 1 As shown, the scanning system 10 may also include a clamping device 300, which is used to fix the sample chamber and can move along the Z-axis to set the sample chamber in different positions.

[0075] It should be noted that the scanning system 10 in this embodiment of the invention does not require the implementation of all the components shown; more or fewer components may be implemented instead. For example, if the detector 200 and transmitter 100 in the scanning system 10 need to rotate along the Z-axis, then in addition to the components shown above, the scanning system may also include a rotating frame, which drives the detector 200 and transmitter 100 to rotate along the Z-axis.

[0076] Figure 2 A schematic flowchart of an embodiment of the sample bin offset determination method provided by the present invention is shown below. Figure 2 As shown, the method for determining the sample bin offset includes:

[0077] S201. Obtain multiple projection images when the sample compartment is located at a preset bed position; the multiple projection images include the first projection image, the second projection image, and the multiple third projection images obtained by scanning the sample compartment when the scanning system is located at a first angle, a second angle, and multiple third angles respectively, and the angle difference between the first angle and the second angle is 180°;

[0078] S202. Determine the first offset and offset angle of the sample compartment based on the first projection map, the second projection map and multiple third projection maps;

[0079] And / or,

[0080] S203. Obtain multiple local projection images of the sample chamber when the scanning system is located at a preset angle; the multiple local projection images are projection images of each segment of the sample chamber when the sample chamber is located at different bed positions;

[0081] S204. Determine the second offset of the sample compartment based on multiple local projection maps.

[0082] Compared with existing technologies, the sample chamber offset determination method provided in this invention first acquires multiple projection images of the sample chamber when it is located at a preset bed position. These projection images include a first projection image, a second projection image, and multiple third projection images obtained by scanning the sample chamber at a first angle, a second angle, and multiple third angles. Then, based on these projection images, the first offset and offset angle of the sample chamber are determined. This eliminates the need to reconstruct the first, second, and third projection images, thus reducing the computational burden of the reconstruction process and improving the efficiency of determining the first offset. Furthermore, this invention acquires multiple local projection images of the sample chamber when the scanning system is located at a preset angle. These local projection images represent projections of different segments of the sample chamber when it is located at different bed positions. The second offset of the sample chamber is determined based on these local projection images, also eliminating the need to reconstruct the local projection images and reducing the computational burden of the reconstruction process, thereby improving the efficiency of determining the second offset. In other words, this improves the efficiency of determining the three-dimensional spatial offset of the sample chamber.

[0083] Furthermore, embodiments of the present invention can obtain the first offset and / or the second offset simply by acquiring the first projection image, the second projection image, the third projection image, and / or a partial projection image, without needing to acquire projection images at various angles. This reduces the exposure time of the scanning system, thereby reducing the aging degree of the scanning system and improving its service life.

[0084] It should be understood that the method of obtaining multiple projection images in step S201 can be either to obtain them in real time through the scanning system 10, or to read or call multiple projection images from a storage medium that stores multiple projection images.

[0085] Similarly, the method for obtaining multiple local projection images in step S203 can be either to obtain them in real time through the scanning system 10, or to read or call multiple local projection images from a storage medium that stores multiple local projection images.

[0086] It should also be understood that the "bed" in step S201 refers to the position of the sample compartment after it moves along the Z-axis under the drive of the clamping device 300. That is, each movement of the clamping device 300 constitutes one bed, and the preset bed refers to a pre-set bed. The number of local projection images in step S203 should be set according to the length of the sample compartment along the Z-axis and the emission range of the transmitter 100. Specifically, the number of local projection images should be equal to the ratio of the length of the sample compartment along the Z-axis to the emission range of the transmitter 100. Furthermore, when obtaining the local projection image, the corresponding segment of the local sample compartment should be moved to the emission range of the transmitter 100 to ensure that the local projection image is a projection image of the corresponding segment of the local sample compartment.

[0087] The preset angle can be set according to the actual application scenario, and is not limited here.

[0088] It should be noted that, in order to improve the clarity and recognizability of the first projection image, the second projection image, the third projection image, and each local projection image, after step S201 and step S203, the first projection image, the second projection image, the third projection image, and each local projection image can be preprocessed such as binarization.

[0089] It should also be noted that: the first offset obtained in steps S201-S202 is the offset of the sample compartment in the XY two-dimensional plane, and the second offset obtained in steps S203-S204 is the offset of the sample compartment in the Z plane. That is, the offset of the sample compartment in the XYZ three-dimensional direction can be obtained through steps S201-S204. The determined first offset, offset angle and second offset can prompt the user to adjust the sample compartment, avoid invalid scanning and improve the scanning reliability of the sample compartment.

[0090] In specific application scenarios, when the sample bin shifts at an angle of 30° along the scanning system 10, due to projection relationships, an offset component can be obtained in the projection image at any angle other than 30° and 210°. The offset components at 210° and 30° represent the true first offset; the offsets in the projection images at other angles are all components of the first offset. Therefore, the first offset should be the maximum offset in the projection images at all angles. Thus, in some embodiments of the present invention, such as... Figure 3 As shown, step S202 includes:

[0091] S301. Determine the first center line of the first projection diagram, the second center line of the second projection diagram, and the multiple third center lines of the multiple third projection diagrams;

[0092] S302. Determine the rotation centerline of the sample chamber based on the first centerline and the second centerline;

[0093] S303, The differences between the first center line, the second center line, and the multiple third center lines and the rotation center line are respectively used as the first angular offset component, the second angular offset component and the multiple third angular offset components of the sample chamber when the scanning device is located at the first angle, the second angle and the multiple third angles.

[0094] S304. Based on the preset fitting model, fit the first angle offset component, the second angle offset component and multiple third angle offset components to obtain the fitting component curve;

[0095] S305. Determine the maximum offset and the corresponding angle in the fitted component curve, and take the maximum offset as the first offset and the corresponding angle as the offset angle.

[0096] In this embodiment of the invention, a first angular offset component, a second angular offset component, and multiple third angular offset components are fitted based on a preset fitting model to obtain a fitted component curve. The maximum offset and the corresponding angle of the maximum offset in the fitted component curve are determined. The maximum offset is used as the first offset and the corresponding angle is used as the offset angle, which can ensure the accuracy and reliability of the determined first offset and offset angle.

[0097] Furthermore, in this embodiment of the invention, it is only necessary to determine the first center line of the first projection image and the second center line of the second projection image, and then determine the rotation center line based on the first center line and the second center line, so as to determine the angular offset components at each angle. The calculation method is simple, thereby further improving the efficiency of determining the first offset.

[0098] In a specific embodiment of the present invention, if the coordinate of the first center line on the U-axis in the two-dimensional projection coordinate system is 20 and the coordinate of the second center line on the U-axis in the two-dimensional projection coordinate system is 40, then the coordinate of the rotation center line on the U-axis in the two-dimensional projection coordinate system is (20+40) / 2=30.

[0099] In a specific embodiment of the present invention, the first projection image is the projection image when the scanning system 10 is at 0°, and the second projection image is the projection image when the scanning system 10 is at 180°, as shown below. Figure 4 As shown, Figure 4 The upper projection is the first projection, the lower projection is the second projection, the first center line is the leftmost dotted line, the second center line is the rightmost dotted line, and the rotation center line is the middle dotted line. The distance between the first center line and the rotation center line is the first angular offset component.

[0100] It should be noted that the preset fitting model should be set according to the variation law of the projection diagram. In the specific embodiment of the present invention, the variation law of the offset of the sample bin conforms to the law of sine function or cosine function, then the preset fitting model is a sine model or a cosine model.

[0101] It should also be noted that the specific number of third projection images can be set or adjusted according to the actual application scenario or experience value, and no specific limit is made here.

[0102] In specific embodiments of the present invention, such as Figure 5 As shown, in addition to the first and second projection maps, there are also 10 third projection maps. Specifically, the first, second, and third projection maps are the projection maps of the scanning system 10 at 0°, 30°, 60°, 90°, 120°, 150°, 180°, 210°, 240°, 270°, 300°, and 330°, respectively. The fitted component curves are shown below. Figure 5 As shown by the curve in the figure, by Figure 4 As can be seen from the curve, the maximum offset in the fitted component curve is the offset component when the scanning system 10 is at 100°. Therefore, the maximum offset can be determined according to the fitted component curve, and the maximum offset can be used as the first offset, and 100° can be used as the offset angle.

[0103] In some embodiments of the present invention, the angles of multiple third projection maps are distributed at equal intervals.

[0104] In some embodiments of the present invention, the first projection map includes at least one layer of first sub-projection map, the second projection map includes at least one layer of second sub-projection map, and each third projection map includes at least one layer of third sub-projection map; then, as follows: Figure 6 As shown, step S301 includes:

[0105] S601. Determine the center coordinates of the first sub-projection diagrams of at least one first sub-projection diagram;

[0106] S602. Determine the center coordinates of each layer of the second sub-projection map in at least one layer of the second sub-projection map;

[0107] S603. Determine the center coordinates of each layer of the third sub-projection diagram in at least one layer of the third sub-projection diagram;

[0108] S604. The line connecting the center coordinates of the first sub-projection diagrams of each layer shall be taken as the first center line;

[0109] S605. The line connecting the center coordinates of the second sub-projection maps of each layer shall be taken as the second center line;

[0110] S606. The line connecting the center coordinates of the third sub-projection diagrams of each layer shall be taken as the third center line.

[0111] Each layer's first sub-projection map is a multi-layered sub-projection map of the first projection map along the V-axis direction in the two-dimensional projection coordinate system. That is, the rows of pixels in the first projection map with different V-coordinate values ​​form each layer's first sub-projection map. Similarly, the rows of pixels in the second projection map with different V-coordinate values ​​form each layer's second sub-projection map, and the rows of pixels in the third projection map with different V-coordinate values ​​form each layer's third sub-projection map.

[0112] In this embodiment of the invention, the line connecting the center coordinates of the first sub-projection images of each layer is used as the first center line, the line connecting the center coordinates of the second sub-projection images of each layer is used as the second center line, and the line connecting the center coordinates of the third sub-projection images of each layer is used as the third center line. The deformation of the sample chamber can be determined using the first, second, and third center lines, thus providing a reference for subsequent maintenance of the sample chamber. The principle is as follows: when the sample chamber is not deformed, the center coordinates of the first sub-projection images of each layer should be the same on the U-axis, the center coordinates of the second sub-projection images of each layer should also be the same on the U-axis, and the center coordinates of the third sub-projection images of each layer should also be the same on the U-axis. Therefore, when the center coordinates of the first sub-projection images of each layer are not the same on the U-axis, and / or the center coordinates of the second sub-projection images of each layer are not the same on the U-axis, and / or the center coordinates of the third sub-projection images of each layer are not the same on the U-axis, it indicates that the sample chamber has deformed.

[0113] In some embodiments of the present invention, the number of layers in at least one first sub-projection map is the same as the number of layers in at least one second sub-projection map; then as follows Figure 7 As shown, step S302 includes:

[0114] S701. The average of the center coordinates of the first sub-projection map of each layer and the center coordinates of the second sub-projection map of each layer corresponding to the first sub-projection map is used as the rotation center coordinates.

[0115] S702. The line connecting the rotation center coordinates of the first sub-projection diagram and the second sub-projection diagram of each layer is taken as the rotation center line.

[0116] Similarly, when the sample chamber does not deform, the coordinates of the rotation center on the U-axis should be the same. Therefore, if the coordinates of the rotation center on the U-axis are different, it also indicates that the sample chamber has deformed. This embodiment of the invention improves the diversity of methods for determining whether the sample chamber has deformed.

[0117] In some embodiments of the present invention, such as Figure 8 As shown, step S204 includes:

[0118] S801. Determine the second offset component of each local sample compartment based on each local projection map;

[0119] S802, take the sum of the second offset components as the second offset amount.

[0120] In specific embodiments of the present invention, such as Figure 9 As shown, the dashed line represents the projection of the sample chamber when it does not shift in the Z direction; the area between two adjacent dashed lines represents the range of a local projection; and the solid line represents the actual projection of the sample chamber. Figure 9 It can be seen that the sample compartment shifted along the Z direction, and the second shift amount is the sum of the second shift components.

[0121] It should be noted that the second offset is the Z-axis offset of the sample compartment at the preset angle.

[0122] In some embodiments of the present invention, each local projection map includes multiple layers of local sub-projection maps; wherein, each layer of local sub-projection map is a multi-layer sub-projection map of the local projection map along the V-axis direction in the two-dimensional projection coordinate system, that is: each row of pixels in the local projection map with different V coordinate values ​​constitutes the local sub-projection map.

[0123] Then step S801 is: take the difference between the two local sub-projection maps with the smallest V coordinate value and the largest V coordinate value as the second offset component.

[0124] However, in practical applications, when the difference between the two local sub-projection maps with the minimum and maximum V-coordinate values ​​is zero as the second offset component, it is possible that the local sub-projection maps with the minimum and maximum V-coordinate values ​​will shift, i.e., the local sample compartment will deform. To address this application scenario, in some embodiments of the present invention, such as... Figure 10 As shown, step S801 includes:

[0125] S1001. Obtain the projection offset of two adjacent local sub-projection maps;

[0126] S1002. The sum of the projection offsets is taken as the second offset component.

[0127] By obtaining the projection offset of two adjacent local sub-projection maps, this embodiment of the invention can determine whether there is an offset between the two adjacent local sub-projection maps, which can further improve the reliability of the judgment on whether the sample chamber has been deformed.

[0128] Depend on Figure 1 It can be seen that different distances between the sample chamber and the transmitter 100 will result in different sizes of the projected images formed in the detector 200. To eliminate this effect, in some embodiments of the present invention, such as... Figure 11 As shown, the method for determining the sample bin offset also includes:

[0129] S1101. Obtain the magnification ratio of the scanning system 10;

[0130] S1102. Perform data restoration processing based on magnification ratio of multiple projection images and multiple local projection images.

[0131] The embodiments of the present invention further improve the accuracy of the first offset determined by multiple projection maps and the second offset determined by the local projection map by performing data restoration processing based on comparing multiple projection maps and multiple local projection maps.

[0132] The magnification ratio can be calibrated before scanning by the scanning system 10 based on the geometric relationship between the scanning system 10 and the sample chamber.

[0133] The data restoration process in step S1102 specifically involves dividing multiple projection images and multiple local projection images by the magnification ratio to eliminate the influence of the magnification ratio on the first offset and the second offset.

[0134] In some embodiments of the present invention, the sample bin offset determination method further includes:

[0135] The sample bins are calibrated based on the offset angle, the first offset, and / or the second offset.

[0136] By calibrating the sample chamber, this invention can improve the reliability of subsequently obtained scanned images and avoid invalid scans by the scanning system.

[0137] In a specific embodiment of the present invention, the sample chamber is calibrated as follows: if the deformation of the sample chamber is less than the preset deformation, the mounting structure of the sample chamber and the vertical motor is manually adjusted based on the offset angle, the first offset and / or the second offset; if the deformation of the sample chamber is greater than or equal to the preset deformation, the sample chamber is directly replaced.

[0138] The preset deformation values ​​can be adjusted according to the actual application scenario and experience values, and no specific limitations are made here.

[0139] To better implement the sample bin offset determination method in this embodiment of the invention, based on the sample bin offset determination method, correspondingly, as follows: Figure 12 As shown, this embodiment of the invention also provides a sample bin offset determination device, the sample bin offset determination device 1200 comprising:

[0140] The projection image acquisition unit 1201 is used to acquire multiple projection images when the sample chamber is located at a preset bed position; the multiple projection images include a first projection image, a second projection image, and multiple third projection images obtained by scanning the sample chamber when the scanning device is located at a first angle, a second angle, and multiple third angles, and the angle difference between the first angle and the second angle is 180°.

[0141] The first offset determination unit 1202 is used to determine the first offset and offset angle of the sample compartment based on the first projection map, the second projection map and multiple third projection maps.

[0142] And / or,

[0143] The local projection image acquisition unit 1203 is used to acquire multiple local projection images of the sample chamber when the scanning system is located at a preset angle; the multiple local projection images are projection images of each segment of the local sample chamber when the sample chamber is located at different bed positions;

[0144] The second offset determination unit 1204 is used to determine the second offset of the sample compartment based on multiple local projection maps.

[0145] The sample bin offset determination device 1200 provided in the above embodiments can realize the technical solutions described in the above sample bin offset determination method embodiments. The specific implementation principles of each module or unit can be found in the corresponding content in the above sample bin offset determination method embodiments, and will not be repeated here.

[0146] like Figure 13 As shown, the present invention also provides a computed tomography (CT) scanner 1300. The CT scanner 1300 includes a processor 1301, a memory 1302, and a display 1303. Figure 13 Only some components of the computed tomography (CT) scanner 1300 are shown; however, it should be understood that implementation of all shown components is not required, and more or fewer components may be implemented instead.

[0147] In some embodiments, processor 1301 may be a central processing unit (CPU), microprocessor or other data processing chip, used to run program code stored in memory 1302 or process data, such as the sample bin offset determination method of the present invention.

[0148] In some embodiments, processor 1301 may be a single server or a group of servers. The server group may be centralized or distributed. In some embodiments, processor 1301 may be local or remote. In some embodiments, processor 1301 may be implemented on a cloud platform. In some embodiments of the present invention, the cloud platform may include private cloud, public cloud, hybrid cloud, community cloud, distributed cloud, inter-cloud, multi-cloud, etc., or any combination thereof.

[0149] In some embodiments, memory 1302 may be an internal storage unit of the computed tomography (CT) scanner 1300, such as a hard disk or memory of the CT scanner 1300. In other embodiments, memory 1302 may also be an external storage device of the CT scanner 1300, such as a pluggable hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., provided on the CT scanner 1300.

[0150] Furthermore, the memory 1302 may include both internal storage units of the computed tomography (CT) scanner 1300 and external storage devices. The memory 1302 is used to store application software and various types of data for which the CT scanner 1300 is installed.

[0151] In some embodiments, display 1303 may be an LED display, a liquid crystal display, a touch-screen liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen. Display 1303 is used to display information from the computed tomography (CT) scanner 1300 and to display a visual user interface. Components 1301-1303 of the CT scanner 1300 communicate with each other via a system bus.

[0152] In some embodiments of the present invention, when the processor 1301 executes the sample bin offset determination program in the memory 1302, the following steps can be implemented:

[0153] Multiple projection images are obtained when the sample compartment is located in a preset bed position; the multiple projection images include the first projection image, the second projection image, and the multiple third projection images obtained by scanning the sample compartment when the scanning device is located at a first angle, a second angle, and multiple third angles, and the angle difference between the first angle and the second angle is 180°;

[0154] The first offset and offset angle of the sample compartment are determined based on the first projection map, the second projection map, and multiple third projection maps.

[0155] And / or,

[0156] Acquire multiple local projection images of the sample chamber when the scanning system is located at a preset angle; the multiple local projection images are projection images of each segment of the sample chamber when the sample chamber is located at different bed positions;

[0157] The second offset of the sample compartment is determined based on multiple local projection maps.

[0158] Furthermore, this embodiment of the invention does not specifically limit the type of the computed tomography (CT) scanner 1300 mentioned. The CT scanner 1300 can be a portable CT scanner such as a mobile phone, tablet computer, personal digital assistant (PDA), wearable device, or laptop computer. Exemplary embodiments of portable CT scanners include, but are not limited to, portable CT scanners running iOS, Android, Microsoft, or other operating systems. The aforementioned portable CT scanner can also be other portable CT scanners, such as laptop computers with touch-sensitive surfaces (e.g., touch panels). It should also be understood that in some other embodiments of the invention, the CT scanner 1300 may not be a portable CT scanner, but rather a desktop computer with a touch-sensitive surface (e.g., a touch panel).

[0159] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware (such as a processor, controller, etc.), and the computer program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0160] The above provides a detailed description of the sample chamber offset determination method, apparatus, and computed tomography (CT) scanning device provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, those skilled in the art will recognize that there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for determining the offset of a sample compartment, applied to a scanning system, the scanning system comprising a sample compartment and a scanning device for scanning the sample compartment, characterized in that, The method for determining the sample bin offset includes: Multiple projection images are obtained when the sample compartment is located at a preset bed position; the multiple projection images include a first projection image, a second projection image, and multiple third projection images obtained by scanning the sample compartment when the scanning device is located at a first angle, a second angle, and multiple third angles, wherein the angle difference between the first angle and the second angle is 180°; Determining the first offset and offset angle of the sample bin based on the first projection image, the second projection image, and multiple third projection images includes: Determine the first center line of the first projection image, the second center line of the second projection image, and the multiple third center lines of the multiple third projection images; The rotation centerline of the sample chamber is determined based on the first centerline and the second centerline; The differences between the first centerline, the second centerline, the plurality of third centerlines and the rotation centerline are respectively used as the first angular offset component, the second angular offset component and the plurality of third angular offset components of the sample compartment when the scanning device is located at the first angle, the second angle and the plurality of third angles; Based on a preset fitting model, the first angle offset component, the second angle offset component, and the plurality of third angle offset components are fitted to obtain the fitting component curve; Determine the maximum offset in the fitted component curve and the corresponding angle of the maximum offset, and take the maximum offset as the first offset and the corresponding angle as the offset angle; And / or, The scanning system acquires multiple local projection images of the sample chamber when it is located at a preset angle; the multiple local projection images are projection images of each segment of the sample chamber when it is located at different bed positions; the bed position refers to the position of the sample chamber after it moves along the Z-axis under the drive of the clamping device; Determining the second offset of the sample bin based on the multiple local projection maps includes: The second offset component of each segment of the local sample compartment is determined based on each of the local projection maps; The sum of the second offset components is taken as the second offset; the second offset is the Z-axis offset of the sample compartment at a preset angle.

2. The method for determining the sample bin offset according to claim 1, characterized in that, The first projection map includes at least one first sub-projection map, the second projection map includes at least one second sub-projection map, and each of the third projection maps includes at least one third sub-projection map; determining the first center line of the first projection map, the second center line of the second projection map, and the plurality of third center lines of the plurality of third projection maps includes: Determine the center coordinates of each layer of the first sub-projection map in the at least one layer of the first sub-projection map; Determine the center coordinates of each layer of the second sub-projection map in the at least one layer of the second sub-projection map; Determine the center coordinates of each layer of the third sub-projection map in the at least one layer of the third sub-projection map; The line connecting the center coordinates of the first sub-projection map of each layer is taken as the first center line; The line connecting the center coordinates of the second sub-projection maps of each layer is taken as the second center line; The line connecting the center coordinates of the third sub-projection maps of each layer is taken as the third center line.

3. The method for determining the sample bin offset according to claim 2, characterized in that, The number of layers in the at least one first sub-projection map is the same as the number of layers in the at least one second sub-projection map; determining the rotation center line based on the first center line and the second center line includes: The average of the center coordinates of the first sub-projection map of each layer and the center coordinates of the second sub-projection map of each layer corresponding to the first sub-projection map is used as the rotation center coordinates; The line connecting the rotation center coordinates of the first sub-projection map and the second sub-projection map of each layer is taken as the rotation center line.

4. The method for determining the sample bin offset according to claim 1, characterized in that, Each of the aforementioned local projection maps includes multiple layers of local sub-projection maps; determining the second offset component of the sample bin based on each of the aforementioned local projection maps includes: Obtain the projection offset of the local sub-projection maps of two adjacent layers; The sum of the projection offsets is taken as the second offset component.

5. The method for determining the sample bin offset according to claim 1, characterized in that, The method for determining the sample bin offset also includes: Obtain the magnification ratio of the scanning device; Data restoration processing is performed on the plurality of projection images and the plurality of partial projection images based on the magnification ratio.

6. The method for determining the sample bin offset according to claim 1, characterized in that, The method for determining the sample bin offset also includes: The sample bin is corrected based on the offset angle, the first offset, and / or the second offset.

7. A sample bin offset determination device, characterized in that, An application in a scanning system, the scanning system comprising a sample chamber and a scanning device for scanning the sample chamber, characterized in that the sample chamber offset determination device comprises: The projection image acquisition unit is used to acquire multiple projection images when the sample compartment is located at a preset bed position; the multiple projection images include a first projection image, a second projection image, and multiple third projection images obtained by scanning the sample compartment when the scanning device is located at a first angle, a second angle, and multiple third angles, wherein the angle difference between the first angle and the second angle is 180°; The first offset determination unit is used to determine the first offset and offset angle of the sample compartment based on the first projection image, the second projection image, and multiple third projection images, including: A first centerline of the first projection image, a second centerline of the second projection image, and multiple third centerlines of the multiple third projection images are determined. A rotation centerline of the sample chamber is determined based on the first centerline and the second centerline. The differences between the first centerline, the second centerline, the multiple third centerlines, and the rotation centerline are respectively used as the first angular offset component, the second angular offset component, and the multiple third angular offset components of the sample chamber when the scanning device is located at the first angle, the second angle, and the multiple third angles. The first angular offset component, the second angular offset component, and the multiple third angular offset components are fitted based on a preset fitting model to obtain a fitted component curve. The maximum offset in the fitted component curve and the corresponding angle of the maximum offset are determined, and the maximum offset is used as the first offset, and the corresponding angle is used as the offset angle. And / or, The local projection image acquisition unit is used to acquire multiple local projection images of the sample chamber when the scanning system is located at a preset angle; the multiple local projection images are projection images of each segment of the sample chamber when the sample chamber is located at different bed positions; the bed position refers to the position of the sample chamber after it moves along the Z-axis under the drive of the clamping device; The second offset determination unit is used to determine the second offset of the sample bin based on the plurality of local projection maps, including: The second offset component of each local sample compartment is determined based on the local projection map; the sum of the second offset components is taken as the second offset; the second offset is the Z-axis offset of the sample compartment at a preset angle.

8. A computed tomography (CT) scanner, characterized in that, Including memory and processor, among which, The memory is used to store programs; The processor, coupled to the memory, is used to execute the program stored in the memory to implement the steps in the sample bin offset determination method according to any one of claims 1 to 6.

Images