Linear CT (Computed Tomography) imaging system and scanning imaging method based on multi-section linear track

Abstract

The invention provides a linear CT imaging system based on multiple linear tracks, and the system comprises a conveying device which is used for enabling a scanning object to move along m preset linear tracks, and m is a positive integer greater than or equal to 2; each scanning section comprises at least one radiation source and at least one detector, n is a positive integer larger than or equal to 2, the radiation source and the detector of at least one scanning section are arranged on the two sides of each section of linear track respectively, the radiation source is used for emitting a radiation beam, and the detector is used for emitting a radiation beam. The detector is used for detecting a ray beam which is emitted by the ray source and passes through a scanned object; in the n scanning sections, the scanning fan angle of at least one scanning section is not equal to the scanning fan angles of the other scanning sections.

Description

Technical Field

[0001] This application relates to the fields of radiation imaging and nondestructive testing technology, and more specifically, to a linear CT imaging system and scanning imaging method based on multi-segment linear trajectories. Background Technology

[0002] For non-destructive testing of industrial products, CT scanning imaging technology is commonly used to detect defects. However, some industrial products are characterized by large size and anisotropic microstructure, making it difficult for X-rays to penetrate in certain directions. In addition, the defect detection process for industrial products requires an assembly line approach, and the fixed geometric position of traditional slip-ring CT scanning imaging systems cannot meet the inspection needs of industrial products.

[0003] It should be noted that the information disclosed in this section is only used to understand the background of the inventive concept of this application. Therefore, the above information may include information that does not constitute prior art. Summary of the Invention

[0004] In view of at least one of the above-mentioned technical problems, embodiments of this application provide a linear CT imaging system and scanning imaging method based on multi-segment linear trajectories.

[0005] According to a first aspect of this application, a linear CT imaging system based on multiple linear trajectories is provided, comprising: a transport device for moving a scanned object along a predetermined m linear trajectory, wherein m is a positive integer greater than or equal to 2; and n scanning segments, each scanning segment including at least one X-ray source and at least one detector, wherein n is a positive integer greater than or equal to 2, wherein at least one X-ray source and detector for each scanning segment are respectively arranged on both sides of each linear trajectory, the X-ray source is used to emit a X-ray beam, and the detector is used to detect the X-ray beam emitted by the X-ray source and passing through the scanned object; in the n scanning segments, the scanning fan angle of at least one scanning segment is not equal to the scanning fan angle of the other scanning segments.

[0006] According to an embodiment of this application, in n scan segments, the scan sector angle of at least one scan segment is smaller than the scan sector angle of the other scan segments.

[0007] According to an embodiment of this application, in n scan segments, the source probe distance of at least one scan segment is not equal to the source probe distance of the other scan segments.

[0008] According to an embodiment of this application, in n scan segments, the source probe distance of at least one scan segment is greater than the source probe distance of other scan segments.

[0009] According to an embodiment of this application, in n scan segments, the source-detection distance of at least one scan segment remains constant during the scanning process.

[0010] According to an embodiment of this application, in n scan segments, the source-detection distance of at least one scan segment varies during the scanning process.

[0011] According to embodiments of this application, each of the n scan segments includes at least one independent X-ray source and at least one detector.

[0012] According to embodiments of this application, in n scan segments, at least two scan segments share at least one radiation source, share at least one detector, or share at least one radiation source and at least one detector.

[0013] According to an embodiment of this application, in m straight line trajectories, at least two straight line trajectories are substantially parallel.

[0014] According to an embodiment of this application, the included angle between at least two straight line trajectories is 180°, and the positions of the at least two straight line trajectories coincide.

[0015] According to embodiments of this application, at least two scanning segments corresponding to at least two straight trajectories share at least one X-ray source, and the motion trajectory of the shared at least one X-ray source is perpendicular to the at least two straight trajectories; or, at least two scanning segments corresponding to at least two straight trajectories share at least one detector, and the motion trajectory of the shared at least one detector is perpendicular to the at least two straight trajectories; or, at least two scanning segments corresponding to at least two straight trajectories share at least one X-ray source and at least one detector, and the relative motion trajectory between the shared at least one X-ray source and at least one detector is perpendicular to the at least two straight trajectories.

[0016] According to an embodiment of this application, in m straight line trajectories, at least two straight line trajectories intersect.

[0017] According to an embodiment of this application, the included angle between at least two straight line trajectories is greater than or equal to 90° and less than 180°.

[0018] According to embodiments of this application, at least two scanning segments corresponding to at least two straight trajectories share at least one X-ray source, and the motion trajectory of the shared at least one X-ray source intersects with at least two straight trajectories respectively; or, at least two scanning segments corresponding to at least two straight trajectories share at least one detector, and the motion trajectory of the shared at least one detector intersects with at least two straight trajectories respectively; or, at least two scanning segments corresponding to at least two straight trajectories share at least one X-ray source and at least one detector, and the relative motion trajectory between the shared at least one X-ray source and at least one detector intersects with at least two straight trajectories respectively.

[0019] According to embodiments of this application, in n scan segments, the source-detection distance of at least one scan segment gradually increases during the scanning process; and / or, in n scan segments, the source-detection distance of at least one scan segment gradually decreases during the scanning process.

[0020] According to an embodiment of this application, in n scanning segments, the relative motion trajectory between the X-ray source and the detector in at least one scanning segment is perpendicular to the straight line trajectory corresponding to that scanning segment.

[0021] According to an embodiment of this application, in n scanning segments, at least one X-ray source in a scanning segment can move along a direction perpendicular to the straight line trajectory corresponding to that scanning segment.

[0022] According to an embodiment of this application, the n scanning segments include a first scanning segment and a second scanning segment, wherein the source-detector distance of the first scanning segment is greater than the source-detector distance of the second scanning segment; the output voltage of at least one X-ray source in the first scanning segment is greater than the output voltage of at least one X-ray source in the second scanning segment, and / or, the output current of at least one X-ray source in the first scanning segment is greater than the output current of at least one X-ray source in the second scanning segment.

[0023] According to an embodiment of this application, the conveying device includes a rotating device for rotating the scanned object; and / or, the system further includes an encoder disposed on the conveying device for positioning the scanned object.

[0024] According to embodiments of this application, at least one scanning segment includes multiple detectors, which are arranged at intervals along a straight track corresponding to the scanning segment, and each detector includes a single row of detection units; or, at least one scanning segment includes multiple detectors, which are arranged at intervals along a straight track corresponding to the scanning segment, and each detector includes multiple rows of detection units; or, at least one scanning segment includes a single detector, which is an area array detector.

[0025] According to an embodiment of this application, the source probe distance of at least one scanning segment is more than 1 meter.

[0026] According to a second aspect of this application, a scanning imaging method using the above-described system is provided, comprising: controlling a scanning object to move along a predetermined m-segment straight-line trajectory; sequentially controlling n scanning segments to scan the scanning object during the movement of the scanning object along the predetermined m-segment straight-line trajectory to obtain projection data detected by each detector in the n scanning segments; and generating a three-dimensional reconstructed image of at least one target detection area in the scanning object based on the projection data detected by each detector in the n scanning segments. Attached Figure Description

[0027] The above and other objects, features and advantages of this application will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0028] Figure 1A A schematic diagram illustrating the projection relationship between the X-ray source, the object being scanned, and the detector;

[0029] Figure 1B A schematic diagram illustrating the three-dimensional relationship between the X-ray source, the object being scanned, and the detector;

[0030] Figure 2 This is a schematic diagram of the structure of a linear CT imaging system according to some exemplary embodiments of this application;

[0031] Figure 3 This is a schematic diagram of the structure of a linear CT imaging system according to some other exemplary embodiments of this application;

[0032] Figure 4A This is a schematic diagram of the structure of an array detector according to some exemplary embodiments of this application;

[0033] Figure 4B This is a schematic diagram illustrating the detector configuration according to some exemplary embodiments of this application;

[0034] Figure 5 This is a schematic diagram of the structure of a linear CT imaging system according to some further exemplary embodiments of this application;

[0035] Figure 6 This is a schematic diagram of the structure of a linear CT imaging system according to some exemplary embodiments of this application, which schematically shows the case where two straight trajectories differ by 180°;

[0036] Figure 7 This is a schematic diagram of the structure of a linear CT imaging system according to some exemplary embodiments of this application, which schematically shows the case where the included angle between two linear trajectories is between 90° and 180°;

[0037] Figure 8 This is a schematic diagram of the structure of a linear CT imaging system according to some exemplary embodiments of this application, which schematically illustrates the case of three linear trajectories;

[0038] Figure 9 This is a schematic diagram of the structure of a linear CT imaging system according to some exemplary embodiments of this application, which schematically illustrates the variation of the source-detector distance during the scanning process;

[0039] Figure 10A This is a schematic diagram of the structure of a scan segment according to some exemplary embodiments of this application;

[0040] Figure 10B This is a schematic diagram of the structure of another scan segment according to some exemplary embodiments of this application;

[0041] Figure 11 A flowchart of a scanning imaging method for a linear CT imaging system according to some exemplary embodiments of this application;

[0042] Figure 12 A block diagram of an electronic device suitable for implementing the method according to an embodiment of this application is shown schematically. Detailed Implementation

[0043] The embodiments of this application will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of this application. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of this application for ease of explanation. However, it will be apparent that one or more embodiments may be implemented without these specific details. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of this application.

[0044] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0045] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0046] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0047] It should be noted that, unless otherwise specified, the terms "first," "second," "third," etc., used in this application are merely for the convenience of referring to different components, such as different radiation sources and detectors, and should not be construed as imposing any form of limitation on the structure of, for example, radiation sources and detectors.

[0048] Computed tomography (CT) imaging refers to the process of using X-rays to perform a tomographic scan of the object being imaged. The analog signals received by the detector are then converted into digital signals, and a computer calculates the attenuation coefficient of each pixel to reconstruct the image, thereby displaying the tomographic structure of each part of the object being imaged.

[0049] Slip-ring CT relies on a rotating gantry to drive the X-ray source and detector to rotate around the workpiece for scanning, thereby acquiring full-angle projection data. In industrial inspection or security inspection fields, for defect detection of large-sized or structurally irregular products, slip-ring CT suffers from limitations such as limited scanning range, poor adaptability to production lines, and low flexibility.

[0050] Specifically, the fixed geometry of the rotating gantry in slip-ring CT scanners results in insufficient coverage for large-sized products (e.g., products longer than 1 meter in any direction) or products with irregular tissue structures. The X-ray beam struggles to penetrate critical areas of the product, limiting the scanning range. Products must be fixed to the rotating platform, requiring frequent attitude adjustments and positioning calibrations, leading to inefficiency and poor assembly line compatibility due to incompatibility with production lines. The fixed scanning angle and detection area of ​​slip-ring CT scanners prevent targeted scanning of regions of interest for different workpieces, resulting in low flexibility. Furthermore, existing slip-ring CT scanners require expanded X-ray beam coverage to achieve full workpiece scanning, leading to redundant radiation in non-detection areas, increasing safety risks and wasting energy.

[0051] In CT scanning imaging systems, it is necessary to acquire projection images of the scanned object from different viewpoints, which are then combined to achieve 3D reconstruction of the object. Traditional acquisition methods achieve this through relative rotational movement between the source / detector assembly and the scanned object. For example, the X-ray source and detector are stationary while the scanned object rotates on a stage, or the scanned object remains stationary while the X-ray source and detector rotate around it. However, this traditional method is unsuitable for large scanned objects (e.g., objects with a dimension exceeding 1 meter). Large objects cannot be placed on a stage, and creating a large mechanical mechanism for rotating the source / detector assembly around such a large object is extremely difficult. To address this, a linear CT scanning imaging technique has been proposed. In this technique, the X-ray source and detector remain stationary, while the scanned object moves along a straight path through the scanning area. The detector arms at different positions measure projection images from different viewpoints, which are then combined to achieve 3D reconstruction of the scanned object. Based on this, the embodiments of this application provide a linear CT imaging system and scanning imaging method based on multi-segment linear trajectories, which are applicable to non-destructive testing of scanned objects in multiple fields such as industrial inspection or security inspection, especially for the inspection of large scanned objects.

[0052] Figure 1A A schematic diagram illustrating the projection relationship between the X-ray source, the object being scanned, and the detector in a linear CT imaging system is shown below. Figure 1A The object being scanned, 3, moves along a straight trajectory between the radiation source 1 and the detector 2. During this movement, radiation emitted from the radiation source 1 (e.g., X-rays, gamma rays) is incident on the object being scanned, and the radiation transmitted through the object being scanned is detected by the detector 2. A spatial point on the object being scanned is transmitted from the radiation source 1 to an image point on the detector 2.

[0053] like Figure 1A As shown, for example, the X-ray source 1 can be a cone-beam X-ray source. The X-rays emitted by the cone-beam X-ray source are distributed in a conical spatial pattern from the point source, which can cover a certain volume of the scanning area at once, and can realize the acquisition of two-dimensional projection data of a certain area of ​​the scanned object in a single projection.

[0054] For example, the radiation source 1 may include an X-ray accelerator, an X-ray machine, or a radioactive isotope, as well as corresponding auxiliary equipment. Optionally, in order to make the horizontal beam angle (i.e., the beam fan angle) greater than 90 degrees, for example, between 90 and 180 degrees, two or more radiation sources may be used, depending on the size of the object being scanned 3 and the application scenario.

[0055] Figure 1B This schematic diagram illustrates the relative positions of the X-ray source, the object being scanned, and the detector in a linear CT imaging system. (Refer to...) Figure 1B For simplicity, in the embodiments of this application, the first direction X can be the direction from the X-ray source 1 towards the detector 2. For example, the first direction X can be a direction perpendicular to the plane where the detector 2 is located. The third direction Z can be the direction of movement of the scanned object 3. In some other embodiments, the third direction Z can also have a certain angle with the direction of movement of the scanned object 3. For example, the third direction Z can have an angle of 10° with the direction of movement of the scanned object 3. The third direction Z can have an angle with the first direction X, and this angle can be greater than zero. For example, the third direction Z and the first direction X can be perpendicular to each other, or, for another example, the third direction Z and the first direction X can have an angle of 60°. The second direction Y can be a direction perpendicular to the plane where the first and second directions are located. For example, ... Figure 1B Taking the direction shown as an example, the second direction Y can be a vertically upward direction.

[0056] In the embodiments of this application, the angle subtended by the X-ray beam emitted from the X-ray source in the horizontal direction, i.e., the angle subtended by the X-ray beam in the XZ plane, is called the fan angle of the X-ray beam, and correspondingly, the direction in which the fan angle of the X-ray beam opens can be called the fan angle direction. The angle subtended by the X-ray beam emitted from the X-ray source in the vertical direction, i.e., the angle subtended by the X-ray beam in the XY plane, is called the cone angle of the X-ray beam, and correspondingly, the direction in which the cone angle of the X-ray beam opens can be called the cone angle direction.

[0057] In the embodiments of this application, for the sake of simplicity, a cuboid is used as an example to describe the linear CT imaging system according to the embodiments of this application. In real-world scenarios, the scanned object 3 can have different three-dimensional shapes, such as a sphere, a cone, or other irregular shapes.

[0058] For example, the radiation source 1 can be an X-ray machine. The detector 2 can be used to receive at least a portion of the radiation beam emitted by the X-ray machine. The detector 2 can include multiple detector modules for detecting the radiation beam of the object being scanned 3, obtaining analog signals, and converting the analog signals into digital signals to output projection data of the object being scanned 3 in relation to X-rays.

[0059] X-ray source 1 is placed on one side of the object being scanned, 3, and detector 2 is placed on the other side. During system operation, the focal point of X-ray source 1 emits a beam of X-rays, and detector 2 acquires transmission data and / or multi-angle projection data of the object being scanned, 3. For example, the data acquisition unit in detector 2 may include a data amplification and shaping circuit, which can operate in (current) integration mode or pulse (counting) mode. The data output cable of detector 2 can be connected to a control device and a data processing device, and the acquired data is stored in the data processing device according to trigger commands.

[0060] Detector 2 can contain multiple independent detection units, which can be arranged in arrays, multiple columns, or with angular intervals, and the interval size can be set as needed. Multiple detection units can form a group and be arranged as a whole, such as forming a detector arm. Each detection unit can independently detect the X-ray beam after it has passed through the scanned object and convert the X-ray signal into digital projection data (such as X-ray attenuation value, light intensity value, etc.). Each detection unit can generate a set of independent projection data.

[0061] Figure 2 This is a schematic diagram of the structure of a linear CT imaging system according to some exemplary embodiments of this application.

[0062] like Figure 2 As shown in the embodiments of this application, a linear CT imaging system based on multiple linear trajectories may include: a transport device 4 and n scanning segments.

[0063] For example, in conjunction with reference Figure 1B and Figure 2 The conveying device 4 can be used to move the scanned object 3 along a predetermined straight trajectory of m segments, where m is a positive integer greater than or equal to 2.

[0064] In the n scan segments, each scan segment includes at least one X-ray source 1 and at least one detector 2, where n is a positive integer greater than or equal to 2.

[0065] For example, on both sides of each straight track, at least one X-ray source 1 and detector 2 for scanning segment are arranged respectively. The X-ray source 1 is used to emit X-ray beams, and the detector 2 is used to detect the X-ray beams emitted by the X-ray source and passing through the scanned object 3.

[0066] It should be noted that, in the embodiments of this application, the attributes of a straight line trajectory include at least the motion path and the motion direction corresponding to the straight line trajectory. Here, the motion path can be understood as the path of the scanning channel corresponding to the straight line trajectory, and the motion direction can be understood as the relative linear motion direction between the scanning object and the source probe component corresponding to the straight line trajectory. It should be understood that if any attribute of two straight line trajectories is different, the two straight line trajectories can be considered different. For example, if both the motion path and the motion direction corresponding to two straight line trajectories are different, then these two straight line trajectories can be considered different; if the motion paths corresponding to two straight line trajectories are the same, but the motion directions are different (for example, the two straight line trajectories correspond to the same scanning channel, but the relative linear motion directions between the scanning object and the source probe component corresponding to the two straight line trajectories are different), then these two straight line trajectories can be considered different.

[0067] In the embodiments of this application, among the n scan segments, the scan sector angle of at least one scan segment is not equal to the scan sector angle of the other scan segments.

[0068] In the embodiments of this application, by setting at least two straight-line trajectories and arranging at least one X-ray source and detector for each scanning segment on both sides of each straight-line trajectory, CT scanning of the object 3 can be performed at each straight-line trajectory, meeting the full-range detection requirements of large-volume or structurally heterogeneous objects, without being limited by the volume and geometry of the object. In particular, the scanning fan angles of the at least two scanning segments can be unequal, that is, the scanning fan angles of each scanning segment can be flexibly designed according to the characteristics of the object, and the unequal fan angles can be used to scan and image the object, thereby achieving better imaging geometry.

[0069] See Figure 2According to some exemplary embodiments of this application, the straight-line trajectory may include two straight-line trajectory segments, i.e., m=2. The n scanning segments may include a first scanning segment and a second scanning segment, with the first scanning segment located upstream of the second scanning segment along the direction of motion. The m straight-line trajectory segments include a first straight-line trajectory 41 and a second straight-line trajectory 42.

[0070] It should be noted that, for ease of description, in the embodiments of this application, the relative positions of the components in the system are determined using the coordinate system of the first scan segment, which includes the first X-ray source 11 and the first detector 21. For example, in Figure 2 In this context, the direction from the first radiation source 11 toward the first detector 21 is taken as the first direction X, the direction in which the first straight trajectory 41 extends is taken as the third direction Z, and the direction perpendicular to both the first direction X and the third direction Z is taken as the second direction Y. Figure 2 The height direction of the scanned object 3. It should be noted that, in the embodiments of this application, the definitions and descriptions of various coordinate systems and directions are merely exemplary descriptions for the convenience of describing the embodiments of this application, and they are not intended to limit the embodiments of this application.

[0071] In the embodiments of this application, the first scanning segment includes a first radiation source 11 and a first detector 21, and the second scanning segment includes a second radiation source 12 and a second detector 22. The first radiation source 11 and the first detector 21 are respectively located on both sides of the first straight track 41. The first radiation source 11 is used to emit a radiation beam, and the first detector 21 is used to detect the radiation beam emitted by the first radiation source and passing through the scanned object 3. The second radiation source 12 and the second detector 22 are respectively located on both sides of the second straight track 42. The second radiation source 12 is used to emit a radiation beam, and the second detector 22 is used to detect the radiation beam emitted by the second radiation source and passing through the scanned object 3. The scanned object 3 can move sequentially along the first straight track 41 and the second straight track 42. When the scanned object moves along the first straight track and passes through the first scanning segment, the first scanning segment can scan the first detection area of ​​the scanned object; when the scanned object moves along the second straight track and passes through the second scanning segment, the second scanning segment can scan the second detection area of ​​the scanned object.

[0072] In the embodiments of this application, the X-ray beam emitted by the X-ray source of the first scanning segment (i.e., the first X-ray source 11) covers the first scanning fan-angle range along the fan-angle direction of the X-ray beam at the first straight track 41, and the X-ray beam emitted by the X-ray source of the second scanning segment (i.e., the second X-ray source 12) covers the second scanning fan-angle range along the fan-angle direction of the X-ray beam at the second straight track 42. The first scanning fan-angle range and the second scanning fan-angle range do not completely overlap.

[0073] See you again Figure 2In the embodiments of this application, the angle between the beam emitted by the first X-ray source 11 in the first scanning segment and the direction of the first straight trajectory is the first scanning sector angle A1. Figure 2 The two dashed lines connecting the first radiation source 11 represent the boundary range of the radiation beam emitted by the first radiation source 11. The angle between the two dashed lines is the first scanning sector angle. The angle between the radiation beam emitted by the second radiation source 12 in the second scanning segment and the direction of the second straight line trajectory is the second scanning sector angle A2. Let... Figure 2 The two dashed lines connected to the second X-ray source 12 represent the boundary range of the X-ray beam emitted by the second X-ray source 12. The angle between the two dashed lines is the second scanning fan angle. The angles of the first and second scanning fan angles can be designed according to actual needs, and the first and second scanning fan angles may not be equal. For example, in some embodiments, when the scanned object 3 is located between the first X-ray source and the first detector, the geometric dimension along the first direction X between the first X-ray source and the first detector is small. To meet the scanning requirements, the distance between the first X-ray source and the first detector in the first direction X can be reduced, and the first scanning fan angle can be set to a larger angle, such as 110°. Correspondingly, when the scanned object is located between the second X-ray source and the second detector, the geometric dimension along the third direction Z between the second X-ray source and the second detector is large, and the second scanning fan angle can be set to a smaller angle, such as 70°.

[0074] In some exemplary embodiments, among the n scan segments, the source probe distance of at least one scan segment is not equal to the source probe distance of the other scan segments.

[0075] It should be noted that, in this application, "source-detector distance" refers to the distance between a radiation source and a detector belonging to the same scanning segment along a straight line trajectory perpendicular to that scanning segment.

[0076] like Figure 2 As shown, in the two scanning segments, the distance L1 between the first X-ray source 11 and the first detector 21 along the first direction X in the first scanning segment (i.e., the source-detector distance in the first scanning segment) is not equal to the distance L2 between the second X-ray source 12 and the second detector 22 along the third direction Z in the second scanning segment (i.e., the source-detector distance in the second scanning segment).

[0077] For example, in Figure 2In the first scanning segment, for objects such as containers, the long side of the object is parallel to the direction of the first scanning trajectory, and the short side is parallel to the direction of the source probe arrangement. In this case, the source probe distance can be appropriately reduced and the scanning fan angle can be increased. In the second scanning segment, the short side of the object is parallel to the direction of the second scanning trajectory, and the long side is parallel to the direction of the source probe arrangement. In this case, the source probe distance can be appropriately increased and the scanning fan angle can be decreased.

[0078] In the embodiments of this application, the first scanning fan angle range has a first scanning fan angle along the fan angle direction of the ray beam, and the second scanning fan angle range has a second scanning fan angle along the fan angle direction of the ray beam. The first scanning fan angle and the second scanning fan angle are not equal.

[0079] In other words, in some embodiments, the first and second scanning fan-angle ranges can be determined according to actual scanning needs, such as the position and shape of the region of interest of the scanned object. This reduces scanning of locations not within the region of interest while fully covering it, thus improving detection efficiency. In the embodiments of this application, the first and second scanning fan-angle ranges do not completely overlap, allowing the fan-angle ranges of the ray beams in the first and second scanning segments to cover different angle intervals, achieving complementarity in angle ranges and enabling sufficient scanning of the object.

[0080] In some embodiments, the first scanning sector range and the second scanning sector range may not overlap at all, thereby enabling full scanning of the object while avoiding repeated scanning of overlapping areas, improving scanning efficiency and reducing resource consumption during the scanning process.

[0081] The linear CT scanning imaging system provided in this application embodiment can, on the one hand, flexibly adjust the scanning sector angle of each scanning segment according to the characteristics of the scanning object, which is beneficial for adapting to the scanning and detection of objects such as containers and large workpieces.

[0082] For example, the X-ray beam emitted by the X-ray source of the first scanning segment forms a first detection area on the scanned object 3, and the X-ray beam emitted by the X-ray source of the second scanning segment forms a second detection area on the scanned object 3, with the first detection area and the second detection area at least partially overlapping.

[0083] In the embodiments of this application, a first scanning segment and a second scanning segment located on different straight-line trajectories respectively form a first detection region and a second detection region on the scanned object. The first detection region and the second detection region at least partially overlap, and the overlapping region is the region of interest of the scanned object. That is to say, on the other hand, by setting the positions of the straight-line trajectory and the scanning segment, multi-angle scanning of the region of interest of the scanned object can be achieved, thereby improving the accuracy of reconstructing the region of interest of the scanned object.

[0084] In some embodiments, at least one scanning segment is set for each straight line trajectory. To meet imaging requirements, two or more scanning segments can be set at intervals along a straight line trajectory. Setting multiple scanning segments improves scanning accuracy and avoids missed scans. The two or more scanning segments along a straight line trajectory can also be redundant to improve the stability and reliability of system operation.

[0085] In some exemplary embodiments, among the n scan segments, the scanning fan angle of at least one scan segment is smaller than that of the other scan segments. For scanning objects such as containers, whose geometric dimensions are large in at least one direction, the distance between the X-ray source and the detector in the scan segment corresponding to that direction can be appropriately increased, and the scanning fan angle can be appropriately decreased to meet the scanning requirements. For example... Figure 2 As shown, in the two scanning segments, the second scanning sector angle A2 of the second scanning segment can be smaller than the first scanning sector angle A1 of the first scanning segment, in order to accommodate the arrangement in the second scanning segment where the short side of the scanned object is parallel to the direction of the second scanning trajectory and the long side is parallel to the direction of the source probe arrangement.

[0086] In some exemplary embodiments, among the n scan segments, the source probe distance of at least one scan segment is greater than the source probe distance of the other scan segments. For example... Figure 2 As shown, in the two scanning segments, the source probe distance of the second scanning segment can be greater than that of the first scanning segment to meet the scanning requirements of the short side direction of the scanned object. This allows the scanned object to pass through the second scanning segment along the second scanning trajectory with the short side direction parallel to the second scanning trajectory and the long side direction parallel to the source probe arrangement direction.

[0087] In some exemplary embodiments, in at least one of the n scan segments, the source-detection distance of the scan segment remains constant throughout the scanning process. See again Figure 2In the two scanning segments, the source-detector distance L1 of the first scanning segment and the source-detector distance L2 of the second scanning segment can both be set to remain constant during the scanning process. That is, the positions of the first X-ray source and the second detector in the first scanning segment remain unchanged during the scanning process, and the positions of the second X-ray source and the second detector in the second scanning segment remain unchanged during the scanning process. In this embodiment, the X-ray source and detector in each scanning segment are set independently and in fixed positions, which facilitates deployment in industrial scenarios. This ensures that the X-ray source and detector in each scanning segment can be fixed in a predetermined optimal position, ensuring the scanning quality of the object being scanned.

[0088] In some embodiments, the source-probe distance of the first scan segment can be set to remain constant during the scanning process, while the source-probe distance of the second scan segment can be set to vary during the scanning process, thereby meeting the scanning requirements for objects of different sizes and improving the adaptability of the linear CT imaging system to different objects.

[0089] In some embodiments, the probe distance of at least one scan segment can be set to remain constant before and during scanning; that is, the probe distance of at least one scan segment remains constant after deployment and is not limited by the scanned object. In other embodiments, the probe distance of at least one scan segment can be set to vary before scanning but remain constant during scanning; that is, the probe distance of at least one scan segment can be adjusted according to actual needs before scanning, and remains constant during scanning after adjustment.

[0090] In some exemplary embodiments, in the n scan segments, the source probe distance of at least one scan segment varies during the scanning process. Setting the source probe distance of at least one scan segment to be variable during scanning improves the adaptability of the scan segment to scanned objects of different sizes. By dynamically changing the source probe distance according to the size of the scanned object during the scanning process, different scanning requirements can be met.

[0091] In some embodiments, the source probe distance of at least one scan segment can be set to remain constant before scanning and vary during scanning. That is, the source probe distance of at least one scan segment has a fixed initial distance after deployment, and can vary according to actual needs based on the size of the scanned object during scanning. In other embodiments, the source probe distance of at least one scan segment can also be set to vary both before and during scanning. That is, the source probe distance of at least one scan segment can vary according to the size of the scanned object before scanning, and can also be dynamically adjusted according to the size of the scanned object, its actual location, and / or the location of the region of interest during scanning to meet actual scanning requirements.

[0092] In some exemplary embodiments, each of the n scan segments includes at least one independent X-ray source and at least one detector. For example... Figure 2 As shown, in the two scanning segments, each scanning segment includes its own independent radiation source and detector. That is, the first scanning segment includes a first radiation source and a first detector, and the second scanning segment includes a second radiation source and a second detector. The first and second radiation sources are independent of each other, and the first and second detectors are also independent of each other. This method of setting up radiation sources and detectors is simple, easy to deploy, and has low control difficulty.

[0093] In some embodiments, among the n scan segments, at least two scan segments share at least one radiation source, share at least one detector, or share at least one radiation source and at least one detector.

[0094] Figure 3 This is a schematic diagram of the structure of a linear CT imaging system according to some other exemplary embodiments of this application. For example... Figure 3 As shown, in the two scanning segments, the first and second scanning segments can also be configured to share a single X-ray source. That is, the first X-ray source 11 in the first scanning segment and the second X-ray source 12 in the second scanning segment are the same X-ray source. During the scanning process, the X-ray source is initially located in the first scanning segment, serving as the first X-ray source 11 to scan the object 3. After the first scanning segment is completed, the X-ray source moves to a preset position in the second scanning segment, serving as the second X-ray source 12 to scan the object. This method is suitable for applications where scanning speed requirements are not high, improving the efficiency of X-ray source utilization and reducing the number of components in a linear CT imaging system.

[0095] It is understandable that the first and second scan segments can also be configured to share a single detector, meaning the first detector in the first scan segment and the second detector in the second scan segment are the same detector. During the scanning process, the detector is initially located in the first scan segment, acting as the first detector to perform imaging. After imaging is completed in the first scan segment, the detector moves to a preset position in the second scan segment, acting as the second detector in the second scan segment to image the scanned object.

[0096] It is also understood that in some other embodiments, the first scanning segment and the second scanning segment may share a single X-ray source and a single detector. That is, the first X-ray source of the first scanning segment and the second X-ray source of the second scanning segment are the same X-ray source, and the first detector of the first scanning segment and the second detector of the second scanning segment are the same detector. During the scanning process, the X-ray source and detector are initially located in the first scanning segment, serving as the first X-ray source and first detector of the first scanning segment to scan and image the object. After the scanning and imaging of the first scanning segment is completed, both the X-ray source and detector move to a preset position in the second scanning segment, serving as the second X-ray source and second detector of the second scanning segment to scan and image the object.

[0097] like Figure 3 As shown, at least two scan segments corresponding to at least two straight-line trajectories share at least one X-ray source, and the motion trajectory of the shared at least one X-ray source (such as...) Figure 3 (as shown by the dashed line with arrows pointing from the first ray source 11 to the second ray source 12) and at least two straight line trajectories (such as...) Figure 3 The first straight line trajectory 41 and the second straight line trajectory 42 intersect each other.

[0098] In other embodiments, at least two scan segments corresponding to at least two straight-line trajectories share at least one detector, and the motion trajectory of the shared at least one detector intersects with the at least two straight-line trajectories respectively. Optionally, at least two scan segments corresponding to at least two straight-line trajectories share at least one X-ray source and at least one detector, and the relative motion trajectory between the shared at least one X-ray source and at least one detector intersects with the at least two straight-line trajectories respectively.

[0099] In embodiments of this application, at least one scanning segment includes multiple detectors, which are arranged at intervals along a straight track corresponding to the scanning segment, and each detector includes a single row of detection units; or, at least one scanning segment includes multiple detectors, which are arranged at intervals along a straight track corresponding to the scanning segment, and each detector includes multiple rows of detection units; or, at least one scanning segment includes a single detector, which is an area array detector.

[0100] In the embodiments of this application, the detector of the scanning segment can be a single area array detector, or it can be composed of multiple single-row detector units or multiple rows of detector units. Figure 4A This is a schematic diagram of the structure of an array detector according to some exemplary embodiments of this application. Figure 4B This is a schematic diagram illustrating the detector configuration according to some exemplary embodiments of this application. For example... Figure 4A , Figure 4BAs shown, taking the first detector as an example, the first detector may include a complete area array detector D1, or it may be composed of multiple single-row detector units or multiple rows of detector units. Taking a single-row detector unit as an example, multiple single-row detector units D2 may be densely arranged or sparsely arranged along the third direction Z, that is, the direction of the straight line trajectory.

[0101] In some embodiments, in m straight line trajectories, at least two straight line trajectories are substantially parallel.

[0102] Figure 5 This is a schematic diagram of the structure of a linear CT imaging system according to some further exemplary embodiments of this application. For example... Figure 5 As shown, in some embodiments, the linear CT imaging system may include three linear trajectories, two of which are substantially parallel. It should be noted that "substantially parallel" here can mean that the two linear trajectories are parallel, or that there is a small angle between the extensions of the two linear trajectories, such as 5°, in which case the two linear trajectories can be considered approximately parallel. In this embodiment, for ease of description, the two substantially parallel linear trajectories are respectively designated as the first linear trajectory 41 and the second linear trajectory 42. The scanning object 3 can move sequentially along the first linear trajectory 41, the third linear trajectory 43, and the second linear trajectory 42. The scanning object 3 can rotate during its movement along the second straight track 42. For example, the scanning object can be set to rotate 90° clockwise after moving to the intersection of the first straight track 41 and the third straight track 43, or rotate 90° clockwise after moving to the intersection of the third straight track 43 and the second straight track 42, or rotate 90° simultaneously during its movement along the third straight track 43, so that it can pass through the first scanning segment and the second scanning segment respectively at the basically parallel first straight track and the second straight track, and scan different positions of the scanning object 3.

[0103] The source-detector distance between the first X-ray source 11 and the first detector 21 in the first scanning segment can remain constant during the scanning process, while the source-detector distance between the second X-ray source 12 and the second detector 22 in the second scanning segment can change before or during the scanning process. For example, in some embodiments, the first X-ray source 11 and the first detector 21 can scan along the long side of the scanning object 3 while the scanning object 3 moves along the first straight track 41; subsequently, the scanning object 3 is rotated 90° clockwise while it moves along the third straight track 43; while the scanning object 3 moves along the second straight track 42, the position of the second detector 22 in the second scanning segment is fixed, and the second X-ray source 12 can move away from the second detector 22, thereby increasing the source-detector distance, and the second X-ray source 12 and the second detector 22 can scan along the short side of the scanning object 3.

[0104] In some embodiments, the included angle between at least two straight line trajectories is 180°, and the positions of the at least two straight line trajectories coincide.

[0105] Figure 6 This is a schematic diagram of the structure of a linear CT imaging system according to some exemplary embodiments of this application. Figure 6 As shown, in some embodiments, the scanning object 3 can also be configured to reciprocate, with at least two straight trajectories being two straight trajectories in the same position but opposite directions. For example, in the two straight trajectories, the first straight trajectories 41 and the second straight trajectories 42 coincide in position but in opposite directions, and the scanning object 3 can reciprocate along the positions of the first straight trajectories 41 and the second straight trajectories 42. In this embodiment, the second scanning segment and the first scanning segment can share a single X-ray source and a single detector. The scanning object 3 can first move along the first straight trajectories 41, being scanned by the first X-ray source 11 and the first detector 21 of the first scanning segment; after moving to the end of the first straight trajectories, it rotates by a set angle, such as 90°, and then moves along the second straight trajectories 42 in the opposite direction to the first straight trajectories. At this time, the first X-ray source and the first detector can serve as the second X-ray source 12 and the second detector 22 of the second scanning segment corresponding to the second scanning trajectory, and the source-detector distance between the second X-ray source 12 and the second detector 22 is set to be variable. For example, the position of the second X-ray source 12 can move in a direction away from the second detector 22, thereby scanning the scanning object 3.

[0106] It should be noted that, in Figure 6 In order to clearly illustrate the first straight line trajectory 41 and the second straight line trajectory 42, the first straight line trajectory 41 and the second straight line trajectory 42 are shown separately. It should be understood that the first straight line trajectory 41 and the second straight line trajectory 42 can be two straight line trajectories that coincide in position but have opposite directions. Accordingly, the first detector 21 and the second detector 22 can be the same detector that is shared, and the second radiation source 12 can be formed by moving the first radiation source 11 downward.

[0107] In some embodiments, at least two scanning segments corresponding to at least two straight trajectories share at least one X-ray source, and the motion trajectory of the shared at least one X-ray source is perpendicular to the at least two straight trajectories; or, at least two scanning segments corresponding to at least two straight trajectories share at least one detector, and the motion trajectory of the shared at least one detector is perpendicular to the at least two straight trajectories; or, at least two scanning segments corresponding to at least two straight trajectories share at least one X-ray source and at least one detector, and the relative motion trajectory between the shared at least one X-ray source and at least one detector is perpendicular to the at least two straight trajectories.

[0108] In some embodiments, when at least two straight-line trajectories are substantially parallel or have an included angle of 180°, the two scanning segments can share a radiation source, a detector, or both. For example, Figure 5 As shown, when the two straight trajectories are essentially parallel, the two scanning segments share a single X-ray source. After the object has passed through the first scanning segment, the first X-ray source can be moved along a direction perpendicular to both the first and second straight trajectories to a position matching the second detector, serving as the second X-ray source for the second scanning segment to scan the object. Alternatively, the two scanning segments share a single detector. After the object has passed through the first scanning segment, the first detector can be moved along a direction perpendicular to both the first and second straight trajectories to a position matching the second X-ray source, serving as the second detector for the second scanning segment to scan the object. Or, the two scanning segments share a single X-ray source and a single detector. After the object has passed through the first scanning segment, the first X-ray source and the first detector can be moved along a direction perpendicular to both the first and second straight trajectories to a corresponding position on the second straight trajectories, serving as the second X-ray source and second detector for the second scanning segment to scan the object.

[0109] In some embodiments, at least two straight line trajectories intersect in the m straight line trajectories.

[0110] See you again Figure 2 In the two straight-line trajectories, the first and second straight-line trajectories intersect. Two scanning segments are set at the first and second straight-line trajectories respectively to scan the object from different directions. The object can only translate along the first and second straight-line trajectories without rotating, and different positions of the object are scanned by the scanning segments located at different positions.

[0111] In some embodiments, the included angle between at least two straight line trajectories is greater than or equal to 90° and less than 180°.

[0112] In some embodiments, the angle between at least two straight line trajectories can be equal to 90°. See again Figure 2 In the two straight-line trajectories, the first and second straight-line trajectories can intersect at an angle of 90 degrees, meaning they are perpendicular to each other. Taking a cuboid as an example, the scanning segments set at the two straight-line trajectories can scan the object from two different sides, obtaining scanning results from different directions and achieving a thorough scan of the object.

[0113] In some embodiments, the included angle between at least two straight trajectories can also be an obtuse angle greater than 90° and less than 180° to meet actual detection and layout requirements. Figure 7 This is a schematic diagram of the structure of a linear CT imaging system according to some exemplary embodiments of this application. Figure 7 As shown, the second straight line trajectory 42 and the first straight line trajectory 41 intersect at an obtuse angle greater than 90° and less than 180°. At this time, the first and second scanning segments, positioned at the two straight line trajectories, can scan the object from different directions to obtain scanning results from different angles, thus achieving a thorough scan of the object.

[0114] In some embodiments, the linear CT imaging system may further include three linear trajectories and three scanning segments, with one scanning segment provided at each linear trajectory. Figure 8 This is a schematic diagram of the structure of a linear CT imaging system according to some exemplary embodiments of this application. Figure 8 As shown, the linear CT imaging system includes a first linear trajectory 41, a second linear trajectory 42, and a third linear trajectory 43. A first scanning segment is located at the first linear trajectory 41, including a first X-ray source 11 and a first detector 21 located on both sides of the first linear trajectory. A second scanning segment is located at the second linear trajectory 42, including a second X-ray source 12 and a second detector 22 located on both sides of the second linear trajectory. A third scanning segment is located at the third linear trajectory 43, including a third X-ray source 13 and a third detector 23 located on both sides of the third linear trajectory. The object being scanned can move sequentially along the first linear trajectory 41, the second linear trajectory 42, and the third linear trajectory 43, thereby receiving scans from the first scanning segment, the second scanning segment, and the third scanning segment, respectively. In some other embodiments, the linear CT imaging system may also include four linear trajectories and four scanning segments, or more than four linear trajectories and more than four scanning segments. This arrangement of multiple linear trajectories and multiple scanning segments allows for scanning of the object in different directions, achieving imaging of the object from complementary multiple angles. It is understood that... Figure 8 The example shown uses a 90° angle between adjacent straight lines. In practice, the angle between each straight line can be set according to actual needs.

[0115] Understandably, the sum of the scanning sector angles of multiple scanning segments can be greater than 180°. When the sum of the scanning sector angles of multiple scanning segments is greater than 180°, each scanning segment can fully scan the object, solving the problem of finite-angle imaging and improving image quality. In other embodiments, the sum of the scanning sector angles of multiple scanning segments can be less than or equal to 180°. In this case, the scanning imaging of the object based on multiple scanning segments is finite-angle imaging. The angular coverage of the projected data is limited, and artifacts generated by finite-angle imaging can be further eliminated through optimization algorithms.

[0116] In some embodiments, in the n scan segments, the source-probe distance of at least one scan segment gradually increases during the scanning process; and / or, in the n scan segments, the source-probe distance of at least one scan segment gradually decreases during the scanning process.

[0117] In embodiments of this application, the source-detector distance of at least one scanning segment can be set to vary during the scanning process to improve the flexibility of the linear CT imaging system and its adaptability to different scanning objects. In some embodiments, the source-detector distance of at least one scanning segment can be set to gradually increase during the scanning process. That is, for the X-ray source and / or detector in the scanning segment, before scanning, the X-ray source and / or detector are located in an initial position with a small initial source-detector distance to prioritize image quality. During the scanning process, the X-ray source or detector, or the X-ray source and detector, can move relative to each other as needed, thereby increasing the source-detector distance of the scanning segment to adapt to the size of the scanning object and to scan larger objects. After the scanning is completed, the X-ray source and / or detector moves back to the initial position to await the next scan.

[0118] In other embodiments, the source-detector distance of at least one scanning segment can be set to gradually increase during the scanning process. That is, for the X-ray source and / or detector in the scanning segment, before scanning, the X-ray source and / or detector is located at an initial position with a large initial source-detector distance to ensure that the object being scanned can pass through. During the scanning process, the X-ray source or detector, or the X-ray source and detector, can move relative to each other as needed to reduce the source-detector distance of the scanning segment in order to adapt to the size of the object being scanned and to scan objects of different sizes. After the scanning is completed, the X-ray source and / or detector moves back to the initial position to wait for the next scan.

[0119] In some embodiments, in the n scan segments, the relative motion trajectory between the X-ray source and the detector in at least one scan segment is perpendicular to the straight line trajectory corresponding to that scan segment.

[0120] During the relative change in the source-detector distance between the X-ray source and the detector, the X-ray source and / or detector can move relative to each other to increase or decrease the source-detector distance. The relative motion trajectory between the X-ray source and the detector can be perpendicular to the straight line trajectory corresponding to the scanning segment to ensure that the X-ray source remains oriented towards the detector during the relative motion, thus avoiding affecting the imaging quality. For example, during the relative motion between the X-ray source and the detector, the projection position of the X-ray source on the detector surface can be maintained at the geometric center of the detector surface to ensure imaging quality and the utilization rate of the detector's detection unit.

[0121] In some embodiments, in the n scan segments, at least one X-ray source in a scan segment is capable of moving along a direction perpendicular to the straight line trajectory corresponding to that scan segment.

[0122] Moving the X-ray source is easier than moving the detector. When changing the source-detector distance in a scanning segment, the distance can be altered by moving the X-ray source while keeping the detector position fixed. During movement, the X-ray source can move perpendicular to the straight line trajectory corresponding to that scanning segment, ensuring that the projection of the X-ray source onto the detector surface remains at the geometric center of the detector surface.

[0123] In some other embodiments, the position of the radiation source can be fixed, and the source-detector distance can be changed by moving the detector. The detector's movement trajectory can move in a direction perpendicular to the straight line trajectory corresponding to the scanning segment, that is, the detector can move in a direction perpendicular to the straight line trajectory corresponding to the scanning segment.

[0124] Figure 9 This is a schematic diagram of the structure of a linear CT imaging system according to some exemplary embodiments of this application. Figure 9 As shown, for a scanning object 3 with a triangular cross-sectional shape, its length varies in different directions. During the scanning imaging process of the scanning object 3, the scanning object 3 can first move along a first straight-line trajectory. During the movement of the scanning object 3, the first X-ray source 11 of the first scanning segment can move in a direction perpendicular to the first straight-line trajectory away from the first detector 21 to increase the source-detector distance of the first scanning segment, so that the scanning object 3 passes through the position between the first X-ray source and the first detector. After the scanning object 3 moves to the end of the first straight-line trajectory, it can be rotated 90 degrees and then move along a second straight-line trajectory. During the movement, the second X-ray source 12 of the second scanning segment can move in a direction perpendicular to the second straight-line trajectory away from the second detector 22 to increase the source-detector distance of the second scanning segment, so that the scanning object 3 passes through the position between the second X-ray source and the second detector.

[0125] In some embodiments, the n scanning segments include a first scanning segment and a second scanning segment, wherein the source-detector distance of the first scanning segment is greater than the source-detector distance of the second scanning segment; the output voltage of at least one X-ray source in the first scanning segment is greater than the output voltage of at least one X-ray source in the second scanning segment, and / or, the output current of at least one X-ray source in the first scanning segment is greater than the output current of at least one X-ray source in the second scanning segment.

[0126] In some embodiments, the output voltage and / or output current of the X-ray source can be determined based on the source-detector distance between the X-ray source and the detector. For example, in a linear CT imaging system, if the source-detector distance of the first scan segment is greater than that of the second scan segment, the output voltage and / or output current of the X-ray source in the first scan segment can be set to be greater than that of the X-ray source in the second scan segment. Increasing the output voltage and / or output current of the X-ray source when the source-detector distance is large, and decreasing the output voltage and / or output current of the X-ray source when the source-detector distance is small, can meet imaging requirements, reduce system power consumption and radiation dose, and ensure system operational safety.

[0127] In the embodiments of this application, the source-detector distance of the scanning segment can be determined according to the geometry of the object being scanned. When scanning a thicker portion of the object, the source-detector distance of the scanning segment at that location needs to be appropriately increased to ensure the object can pass through. This can be achieved by increasing the output voltage and / or current of the X-ray source, thus ensuring image quality for thicker objects. Conversely, when scanning a thinner portion of the object, the source-detector distance of the scanning segment at that location can be appropriately decreased. This can be achieved by reducing the output voltage and / or current of the X-ray source to lower power consumption and radiation levels.

[0128] In some embodiments, the conveying device includes a rotating device for rotating the scanned object; and / or, the system further includes an encoder 5 disposed on the conveying device for positioning the scanned object.

[0129] In some embodiments, the object to be scanned can be rotated along its own axis using a rotating device. Figure 5 For example, after moving to the end of the first linear trajectory, the object can be rotated 90° clockwise by a rotating device, and then move along the second linear trajectory. Thus, different positions of the object can be scanned using the first scanning segment at the first linear trajectory and the second scanning segment at the second linear trajectory.

[0130] In some embodiments, the system may further include an encoder disposed on the conveying device, the encoder being used to locate the position of the scanned object.

[0131] Understandably, an encoder can be a device capable of converting angular or linear displacement into electrical signals to determine position. In some embodiments, the encoder can convert angular displacement into electrical signals, and the conveying device can include a drive device capable of converting rotational motion into linear motion, such as a conveyor belt. The encoder can be positioned at the rotation mechanism where the drive device rotates to determine the position of the scanned object based on the rotation angle of the rotation mechanism. The time and position of the scanned object placed on the conveying device can be determined by using sensors, and the position of the scanned object can be determined based on this time and position combined with the rotation angle detected by the encoder. Alternatively, the conveying device can be configured to trigger when the scanned object is placed, with the encoder synchronously recording the rotation angle when the conveying device is triggered, thereby determining the position of the scanned object.

[0132] In other embodiments, the encoder can convert linear displacement signals into electrical signals. The encoder can be placed on the transmission device to directly determine the position of the scanned object based on the detected displacement signals.

[0133] Figure 10A This is a schematic diagram of the structure of a scan segment according to some exemplary embodiments of this application. For example... Figure 10A As shown, in some embodiments, for at least one of the n scanning segments, multiple X-ray sources may be included, and the multiple X-ray sources are arranged at intervals along the fan-angle direction of the X-ray beam.

[0134] In some embodiments, if the angular coverage of a single X-ray source does not meet the imaging requirements, multiple X-ray sources can be set in a scanning segment to improve the X-ray coverage. For example, if in some scenarios the imaging of the scanned object requires a scanning fan angle of 90°, but the maximum scanning fan angle corresponding to each X-ray source is 45°, then two X-ray sources can be set at intervals along the fan angle direction of the X-ray beam. X-ray source one 101 covers a 45° fan angle range on one side of the scanned object 3, and X-ray source two 102 covers a 45° fan angle range on the other side of the scanned object 3. X-ray source one 101 and X-ray source two 102 can be configured to share a set of detectors, and X-ray source one 101 and X-ray source two 102 alternately emit beams for imaging.

[0135] Understandably, in other embodiments, the number of X-ray sources in a scanning segment may be 3, 4, 5, or other numbers. The coverage areas of the X-ray beams emitted by multiple X-ray sources in the fan-angle direction may partially overlap or not overlap at all. The coverage areas of the X-ray beams from each X-ray source in the fan-angle direction may be the same or different.

[0136] In some embodiments, at least one of the n scan segments may include a plurality of detectors, each of which receives a beam of radiation emitted from a plurality of radiation sources.

[0137] Optionally, at least one of the n scan segments includes a single detector, and multiple radiation sources share a single detector.

[0138] For a scan segment containing multiple radiation sources, the sources can share a single detector, or each source can be configured with its own dedicated detector. For example, consider a scan segment containing two radiation sources... Figure 10A As shown, X-ray source 101 and X-ray source 202 can share a single detector 2. During the scanning process, the scanned object 3 moves along a straight trajectory, and X-ray source 101 and X-ray source 202 can alternately emit beams to achieve scanning imaging.

[0139] Figure 10B This is a schematic diagram of the structure of another scan segment according to some exemplary embodiments of this application, such as... Figure 10B As shown, X-ray source 101 and X-ray source 202 can each correspond to a detector, that is, X-ray source 101 corresponds to detector 201, and X-ray source 202 corresponds to detector 202. During the scanning process, the object 3 moves along a straight trajectory, and X-ray source 101 and X-ray source 202 can emit beams simultaneously, achieving scanning imaging of the object 3 through detector 1 and detector 2 respectively.

[0140] In the embodiments of this application, the source probe distance of at least one scanning segment is more than 1 meter.

[0141] Traditional CT scanning imaging systems are unsuitable for acquiring large objects (such as shipping containers) with dimensions exceeding 1 meter in any dimension. Large objects cannot be placed on a stage, and creating a large mechanical mechanism to rotate the probe assembly around the object is difficult. However, in the embodiments of this application, the probe distance of the scanning segment can be adjusted according to actual needs, thus adapting to the scanning requirements of large objects. For large objects with dimensions exceeding 1 meter in any dimension, the probe distance of the corresponding scanning segment can be set to more than 1 meter to facilitate scanning.

[0142] Figure 11 This is a flowchart of a scanning imaging method for a linear CT imaging system according to some exemplary embodiments of this application. In the embodiments of this application, based on the linear CT imaging system provided above, a scanning imaging method for that system is also provided. The method includes steps S1110 to S1130.

[0143] In step S1110, the scanning object is controlled to move along a predetermined m-segment straight trajectory.

[0144] Understandably, the object to be scanned can be placed on a conveyor and the conveyor can be controlled to move the object along a predetermined m-segment straight trajectory.

[0145] In step S1020, during the process of the scanned object moving along a predetermined m-segment straight trajectory, n scanning segments are sequentially controlled to scan the scanned object in order to obtain the projection data detected by each detector in the n scanning segments.

[0146] Understandably, at least one scanning segment is set at each straight line trajectory. As the scanned object moves along the predetermined m straight line trajectories, it will pass through the scanning segments at each straight line trajectory. The X-ray source of the corresponding scanning segment can be controlled to emit X-rays, and the projection data received at the detector can be collected.

[0147] In step S1030, a three-dimensional reconstructed image of at least one target detection area in the scanned object is generated based on the projection data detected by each detector in the n scan segments.

[0148] Understandably, there can be one or more target detection regions. When there is only one target detection region, a 3D reconstructed image of that region can be generated based on the projection data detected by each detector. For example, the target detection region can be the entire area of ​​the scanned object. When there are multiple target detection regions, each region corresponds to at least two scanning segments. The overlapping area of ​​these two segments within the detection region of the scanned object is the corresponding target detection region. A 3D reconstructed image of each target detection region can be obtained by performing 3D reconstruction on the projection data detected by the corresponding detectors.

[0149] It should be noted that the numbering of each step in the above method is not a restriction on the order of the method. In the absence of conflict, the steps in the method can be executed in parallel or in a different order than that described in this application.

[0150] Figure 12 A block diagram of an electronic device suitable for implementing the methods described above, according to an embodiment of this application, is illustrated schematically. Figure 12 The illustrated electronic device is merely an example and should not be construed as limiting the functionality or scope of the embodiments of this application. For instance, in embodiments of this application, an imaging device may be implemented as the electronic device described. Furthermore, the imaging device may also be implemented as... Figure 12 The illustrated electronic device is in the form of a display screen. The embodiments of this application do not impose any particular limitation on the specific implementation of the imaging device.

[0151] like Figure 12As shown, an electronic device 1200 according to an embodiment of this application includes a processor 1201, which can perform various appropriate actions and processes according to a program stored in a read-only memory 1202 or a program loaded from a storage portion 1208 into a random access memory 1203. The processor 1201 may include, for example, a general-purpose microprocessor, an instruction set processor and / or an associated chipset and / or a dedicated microprocessor. The processor 1201 may also include onboard memory for caching purposes. The processor 1201 may include a single processing unit or multiple processing units for executing different steps of the method flow according to an embodiment of this application.

[0152] Random access memory 1203 stores various programs and data required for the operation of electronic device 1200. Processor 1201, read-only memory 1202, and random access memory 1203 are interconnected via bus 1204. Processor 1201 executes various steps of the method flow according to embodiments of this application by executing programs in read-only memory 1202 and / or random access memory 1203. It should be noted that the programs may also be stored in one or more memories other than read-only memory 1202 and random access memory 1203. Processor 1201 may also execute various steps of the method flow according to embodiments of this application by executing programs stored in said one or more memories.

[0153] According to embodiments of this application, the electronic device 1200 may further include an input / output interface 1205, which is also connected to the bus 1204. The electronic device 1200 may also include one or more of the following components connected to the input / output interface 1205: an input section 1206 including a keyboard, mouse, etc.; an output section 1207 including a cathode ray tube, liquid crystal display, etc., and a speaker, etc.; a storage section 1208 including a hard disk, etc.; and a communication section 1209 including a model interface card such as a local area network card, modem, etc. The communication section 1209 performs communication processing via a model such as the Internet. A driver 1210 is also connected to the input / output interface 1205 as needed. A removable medium 1211, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on the driver 1210 as needed so that computer programs read from it can be installed into the storage section 1208 as needed.

[0154] Embodiments of this application also provide a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments; or it may exist independently and not assembled into the device / apparatus / system. The computer-readable storage medium carries one or more programs, which, when executed, implement the method according to the embodiments of this application.

[0155] According to embodiments of this application, the computer-readable storage medium can be a non-volatile computer-readable storage medium, such as including but not limited to: portable computer disks, hard disks, random access memory, read-only memory, erasable programmable read-only memory, portable compact disk read-only memory, optical storage devices, magnetic storage devices, or any suitable combination thereof. In embodiments of this application, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. For example, according to embodiments of this application, the computer-readable storage medium may include the read-only memory 1202, and / or random access memory 1203, and / or one or more memories other than read-only memory 1202 and random access memory 1203 described above.

[0156] Embodiments of this application also include a computer program product comprising a computer program containing program code for performing the methods shown in the flowchart. When the computer program product is run on a computer system, the program code is used to cause the computer system to implement the methods provided in the embodiments of this application.

[0157] In one embodiment, the computer program may rely on a tangible storage medium such as an optical storage device or a magnetic storage device. In another embodiment, the computer program may also be transmitted and distributed in the form of signals on a model medium, and downloaded and installed via the communication section 1209, and / or installed from the removable medium 1211. The program code contained in the computer program can be transmitted using any suitable model medium, including but not limited to: wireless, wired, etc., or any suitable combination thereof.

[0158] In embodiments of this application, the computer program can be downloaded and installed from the model via the communication section 1209, and / or installed from the removable medium 1211. When the computer program is executed by the processor 1201, it performs the functions defined in the system of this application embodiment. According to embodiments of this application, the systems, devices, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0159] According to embodiments of this application, program code for executing the computer programs provided in the embodiments of this application can be written in any combination of one or more programming languages. Specifically, these computational programs can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. The program code can be executed entirely on the user's computing device, partially on the user's device, partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of model, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0160] The embodiments of this application have been described above. However, these embodiments are merely illustrative and not intended to limit the scope of this application. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Without departing from the scope of this application, those skilled in the art can make various substitutions and modifications, all of which should fall within the scope of this application.

Claims

1. A linear CT imaging system based on multi-segment linear trajectories, characterized in that, The system includes: A conveying device is used to move a scanned object along a predetermined m-segment straight-line trajectory, where m is a positive integer greater than or equal to 2; and There are n scan segments, each including at least one X-ray source and at least one detector, where n is a positive integer greater than or equal to 2. In this configuration, at least one X-ray source and detector for the scanning segment are arranged on both sides of each straight line trajectory. The X-ray source is used to emit X-ray beams, and the detector is used to detect X-ray beams emitted by the X-ray source and passing through the scanned object. In the n scan segments, the scan sector angle of at least one scan segment is not equal to the scan sector angle of the other scan segments.

2. The system according to claim 1, characterized in that, In the n scan segments, the scan sector angle of at least one scan segment is smaller than that of the scan sector angles of the other scan segments.

3. The system according to claim 1 or 2, characterized in that, In the n scan segments, the source probe distance of at least one scan segment is not equal to the source probe distance of the other scan segments.

4. The system according to any one of claims 1-3, characterized in that, In the n scan segments, the source probe distance of at least one scan segment is greater than the source probe distance of the other scan segments.

5. The system according to claim 1 or 2, characterized in that, In the n scan segments, the source-probe distance of at least one scan segment remains constant during the scanning process.

6. The system according to claim 1 or 2, characterized in that, In the n scan segments, the source-detection distance of at least one scan segment changes during the scanning process.

7. The system according to any one of claims 1-6, characterized in that, Each of the n scanning segments includes at least one independent X-ray source and at least one detector.

8. The system according to any one of claims 1-6, characterized in that, In the n scan segments, at least two scan segments share at least one radiation source, at least one detector, or at least one radiation source and at least one detector.

9. The system according to any one of claims 1-8, characterized in that, In the m straight line trajectories, at least two straight line trajectories are substantially parallel.

10. The system according to claim 9, characterized in that, The included angle between the at least two straight line trajectories is 180°, and the positions of the at least two straight line trajectories coincide.

11. The system according to claim 9 or 10, characterized in that, At least two scan segments corresponding to the at least two straight line trajectories share at least one X-ray source, and the motion trajectory of the shared at least one X-ray source is perpendicular to the at least two straight line trajectories; or, At least two scan segments corresponding to the at least two straight-line trajectories share at least one detector, and the motion trajectory of the shared at least one detector is perpendicular to the at least two straight-line trajectories; or, At least two scanning segments corresponding to the at least two straight-line trajectories share at least one X-ray source and at least one detector, and the relative motion trajectory between the shared at least one X-ray source and at least one detector is perpendicular to the at least two straight-line trajectories.

12. The system according to any one of claims 1-8, characterized in that, In the m straight-line trajectories, at least two straight-line trajectories intersect.

13. The system according to claim 12, characterized in that, The included angle between the at least two straight lines is greater than or equal to 90° and less than 180°.

14. The system according to claim 12 or 13, characterized in that, At least two scanning segments corresponding to the at least two straight line trajectories share at least one X-ray source, and the motion trajectory of the shared at least one X-ray source intersects with the at least two straight line trajectories respectively; or, At least two scanning segments corresponding to the at least two straight-line trajectories share at least one detector, and the motion trajectory of the shared at least one detector intersects with the at least two straight-line trajectories respectively; or, At least two scanning segments corresponding to the at least two straight-line trajectories share at least one X-ray source and at least one detector, and the relative motion trajectory between the shared at least one X-ray source and at least one detector intersects the at least two straight-line trajectories respectively.

15. The system according to claim 6, characterized in that, In the n scan segments, the source-probe distance of at least one scan segment gradually increases during the scanning process; and / or, In the n scan segments, the source-probe distance of at least one scan segment gradually decreases during the scanning process.

16. The system according to claim 6 or 15, characterized in that, In the n scanning segments, the relative motion trajectory between the X-ray source and the detector in at least one scanning segment is perpendicular to the straight line trajectory corresponding to that scanning segment.

17. The system according to claim 16, characterized in that, In the n scanning segments, at least one of the X-ray sources in the scanning segment can move along a direction perpendicular to the straight line trajectory corresponding to that scanning segment.

18. The system according to any one of claims 1-17, characterized in that, The n scanning segments include a first scanning segment and a second scanning segment, wherein the source detection distance of the first scanning segment is greater than the source detection distance of the second scanning segment; The output voltage of at least one X-ray source in the first scanning segment is greater than the output voltage of at least one X-ray source in the second scanning segment, and / or the output current of at least one X-ray source in the first scanning segment is greater than the output current of at least one X-ray source in the second scanning segment.

19. The system according to any one of claims 1-18, characterized in that, The conveying device includes a rotating device for rotating the scanned object; and / or, The system also includes an encoder mounted on the conveying device, the encoder being used to locate the position of the scanned object.

20. The system according to any one of claims 1-19, characterized in that, At least one scan segment includes multiple detectors, which are arranged at intervals along a straight trajectory corresponding to the scan segment, and each detector includes a single row of detection units; or... At least one scan segment includes multiple detectors, which are arranged at intervals along a straight trajectory corresponding to the scan segment, and each detector includes multiple rows of detection units; or... At least one scan segment includes a single detector, which is an area array detector.

21. The system according to any one of claims 1-20, characterized in that, At least one scanning segment has a source-detection distance of more than 1 meter.

22. A scanning imaging method using the system according to any one of claims 1-21, characterized in that, The method includes: Control the scanning object to move along a predetermined m-segment straight-line trajectory; During the process of the scanned object moving along a predetermined m-segment straight trajectory, the n-segment scanning is sequentially controlled to scan the scanned object in order to obtain the projection data detected by each detector in the n-segment scanning; Based on the projection data detected by each detector in the n scanning segments, a three-dimensional reconstructed image of at least one target detection area in the scanned object is generated.

Images