A CT system and security screening apparatus

Abstract

The application relates to the technical field of CT imaging equipment, and discloses a CT system and a security inspection equipment. The CT system comprises a rectangular channel extending along the Z direction, a rotating assembly, a ray source and a detector assembly. The detector assembly comprises a middle detector and an edge detector, the rays of the ray source pass through the rectangular channel and irradiate the detector assembly, when the rotating frame rotates by 360 degrees, an annular edge detection area for detecting the rectangular channel is formed between the ray source and the edge detector, the overlapping part of the annular edge detection area and the rectangular channel is not greater than the non-overlapping part of the annular edge detection area and the rectangular channel; the number of rows of crystal modules on the first sub-edge detector and the second sub-edge detector is half of the number of rows of crystal modules on the middle detector; the crystal modules of the first sub-edge detector and the second sub-edge detector are staggered along the Z direction and have no overlapping position.

Description

Technical Field

[0001] This invention relates to the field of CT imaging equipment technology, and more particularly to a CT system and security inspection equipment. Background Technology

[0002] Currently, a CT (Computed Tomography) system consists of a radiation source, detector, rotor, data transmission system, computer, gantry, and drive system. The radiation source and detector are both mounted on the rotor and rotate together. The object being examined is placed on a conveyor belt and moved along the Z-axis. The radiation source emits X-rays, which pass through the object, and the remaining rays are received by the detector. The data received by the detector is transmitted to the computer via a wireless data transmission system. The computer processes the data, analyzes information such as the internal density of the object, and ultimately forms a CT image. The radiation source and detector continuously rotate around the object, irradiating it from different angles and receiving residual X-rays. The data received by the detector is transmitted to the computer via a wireless data transmission system. The computer processes the data, analyzes information such as the shape and atomic number of the object, and ultimately forms a CT image of the object.

[0003] In existing technologies, edge detectors affect the rotation radius. To reduce the size of CT systems, edge detectors are moved towards the X-ray source, thereby reducing the maximum rotation radius of the gantry. However, when the edge detector moves towards the X-ray source, it needs to be proportionally reduced along the Z-axis. Therefore, the crystal row spacing of the edge detector must be reduced to meet the requirements of conventional algorithms and performance. However, reducing the row spacing increases the difficulty of detector fabrication, leading to higher costs, and current technology may not even be able to meet the processing requirements of edge detectors.

[0004] Therefore, there is an urgent need for a CT system and security inspection equipment to solve the aforementioned problems. Summary of the Invention

[0005] Based on the above, the purpose of this invention is to provide a CT system and security inspection equipment that reduces the processing difficulty of the first sub-edge detector and the second sub-edge detector, thereby reducing production costs.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] On the one hand, a CT system is provided, comprising:

[0008] A rectangular channel extending along the Z-axis;

[0009] A rotating assembly, comprising a rotating frame circumferentially disposed within the rectangular channel;

[0010] A radiation source and a detector assembly, both of which are mounted on the rotating frame, and the radiation source and the detector assembly are disposed on both sides of the rectangular channel;

[0011] The detector assembly includes an intermediate detector and an edge detector. The edge detector includes a first sub-edge detector and a second sub-edge detector symmetrically arranged on both sides of the intermediate detector. The X-ray from the X-ray source passes through the rectangular channel and irradiates the detector assembly. When the rotating frame rotates 360 degrees, an annular edge detection area for detecting the rectangular channel is formed between the X-ray source and the edge detector. The overlapping portion of the annular edge detection area and the rectangular channel is not greater than the non-overlapping portion of the annular edge detection area and the rectangular channel.

[0012] The intermediate detector, the first sub-edge detector, and the second sub-edge detector are all uniformly spaced along the Z direction with multiple rows of crystal modules. The number of rows of crystal modules on the first sub-edge detector is the same as the number of rows of crystal modules on the second sub-edge detector, and the number of rows of crystal modules on the first sub-edge detector is half the number of rows of crystal modules on the intermediate detector.

[0013] The crystal modules of the first sub-edge detector and the crystal modules of the second sub-edge detector are staggered along the Z-direction and have no overlapping positions.

[0014] As a preferred technical solution for a CT system, the intermediate detector is disposed on the first arc surface, the edge detector is disposed on the second arc surface, the first arc surface and the second arc surface are coaxially disposed, and the X-ray source is disposed on the axis of the first arc surface and the second arc surface.

[0015] As a preferred technical solution for a CT system, the second arc surface does not interfere with the rectangular channel, and the second arc surface does not exceed the outer diameter of the rotating frame.

[0016] As a preferred technical solution for a CT system, the radius of the second arc surface is smaller than the radius of the first arc surface.

[0017] As a preferred technical solution for a CT system, the radius of the first arc surface is Ra, the radius of the second arc surface is Rb, and the length of the intermediate detector is Da, wherein Ra / Rb=Da / Db.

[0018] As a preferred technical solution for a CT system, the spacing of the crystal modules on the intermediate detector is da, the spacing of the crystal modules on the first sub-edge detector and the spacing of the crystal modules on the second sub-edge detector are both db, and the first sub-edge detector is provided with N rows of crystal modules, and the intermediate detector is provided with 2N rows of crystal modules, where Db=db*(N-1) and Da=da*(2N-1).

[0019] As a preferred technical solution for a CT system, the crystal module of the first sub-edge detector and the crystal module of the second sub-edge detector are spaced 1 / 2 dB apart along the Z direction.

[0020] As a preferred technical solution for a CT system, the radiation path of the radiation source irradiating the edge detector and the radiation path of the radiation source irradiating the middle detector are adjacent to each other on one side.

[0021] As a preferred technical solution for a CT system, the edge detectors are in multiple sets, and the second arc surface is in multiple forms, with each set of edge detectors corresponding to one of the multiple second arc surfaces.

[0022] On the other hand, a security inspection device is provided, including the CT system described in any of the above solutions.

[0023] The beneficial effects of this invention are as follows:

[0024] This invention provides a CT system and security inspection equipment. During operation, the rotating frame drives the X-ray source and detector assembly to rotate together around a rectangular channel. When the rotating frame rotates 360 degrees, an annular edge detection area is formed between the X-ray source and the edge detector to detect the rectangular channel. The overlapping part of the annular edge detection area and the rectangular channel is the area to be imaged, and the non-overlapping part of the annular edge detection area and the rectangular channel is air, which does not need to be calculated and reconstructed into an image. The amount of calculation is small. Therefore, the first sub-edge detector and the second sub-edge detector only require a small number of crystal modules to form an image of this thickness. In this invention, the overlapping portion of the annular edge detection area and the rectangular channel is no larger than the non-overlapping portion, i.e., detecting the four sharp corner areas of the rectangular channel. Compared to the intermediate detector, the amount of data that the edge detector needs to calculate is reduced by more than half. Therefore, the number of rows of crystal modules on the first sub-edge detector and the second sub-edge detector can be set to half the number of rows of crystal modules on the intermediate detector. When the number of rows on the first and second sub-edge detectors is reduced, the spacing between the crystal modules can be relatively increased, reducing the processing difficulty of the first and second sub-edge detectors, thereby reducing production costs.

[0025] Furthermore, since the first and second sub-edge detectors are symmetrically arranged on both sides of the middle detector, and their detection positions are within the same annular edge detection area, in order to ensure the imaging effect of this annular edge detection area, the crystal modules of the first and second sub-edge detectors are staggered along the Z-direction without overlapping. That is, the sum of the number of data layers acquired by the crystal module of the first and second sub-edge detectors is equal to the number of data layers acquired by the crystal module of the first sub-edge detector, thus meeting the imaging requirements of the CT system for forming CT images. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0027] Figure 1 This is one of the front views of the CT system provided in a specific embodiment of the present invention;

[0028] Figure 2 This is a top view of the edge detector provided in a specific embodiment of the present invention;

[0029] Figure 3 This is a top view of the intermediate detector provided in a specific embodiment of the present invention;

[0030] Figure 4 This is a left view of a portion of the structure of the CT system provided in a specific embodiment of the present invention;

[0031] Figure 5 This is the second front view of the CT system provided in a specific embodiment of the present invention;

[0032] Figure 6 This is a structural schematic diagram of the security inspection equipment provided in a specific embodiment of the present invention.

[0033] The markings in the image are as follows:

[0034] 10. The object being detected;

[0035] 1. Rectangular channel;

[0036] 2. Rotating assembly; 21. Rotating frame; 22. Frame;

[0037] 3. Radiation source;

[0038] 4. Detector assembly; 41. Intermediate detector; 42. Edge detector; 421. First sub-edge detector; 422. Second sub-edge detector; 423. Annular edge detection area; 4231. Overlapping part; 4232. Non-overlapping part; 43. Crystal module; 44. Ray path;

[0039] 5. Conveyor belt; 6. Data transmission component. Detailed Implementation

[0040] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0041] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0043] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0044] like Figures 1-3As shown, this embodiment provides a CT system, which includes a rectangular channel 1 extending along the Z direction, a rotating assembly 2, a radiation source 3, and a detector assembly 4.

[0045] Specifically, the rotating assembly 2 includes a rotating frame 21, which is arranged around the rectangular channel 1; a radiation source 3 and a detector assembly 4, both mounted on the rotating frame 21 and positioned on opposite sides of the rectangular channel 1; the detector assembly 4 includes a central detector 41 and an edge detector 42, the edge detector 42 including a first sub-edge detector 421 and a second sub-edge detector 422 symmetrically arranged on opposite sides of the central detector 41; the radiation from the radiation source 3 passes through the rectangular channel 1 and irradiates the detector assembly 4; when the rotating frame 21 rotates 360 degrees, an annular edge detection area 423 is formed between the radiation source 3 and the edge detector 42 to detect the edge of the rectangular channel 1. The overlapping portion 4231 with the rectangular channel 1 is not larger than the non-overlapping portion 4232 of the annular edge detection area 423 and the rectangular channel 1; the intermediate detector 41, the first sub-edge detector 421 and the second sub-edge detector 422 are all uniformly spaced along the Z direction with multiple rows of crystal modules 43. The number of rows of crystal modules 43 on the first sub-edge detector 421 is the same as the number of rows of crystal modules 43 on the second sub-edge detector 422, and the number of rows of crystal modules 43 on the first sub-edge detector 421 is half the number of rows of crystal modules 43 on the intermediate detector 41; the crystal modules 43 of the first sub-edge detector 421 and the crystal modules 43 of the second sub-edge detector 422 are staggered along the Z direction and have no overlapping positions.

[0046] During operation, the rotating frame 21 drives the X-ray source 3 and the detector assembly 4 to rotate together around the rectangular channel 1. When the rotating frame 21 rotates 360 degrees, an annular edge detection area 423 is formed between the X-ray source 3 and the edge detector 42 to detect the edge of the rectangular channel 1. The overlapping part 4231 of the annular edge detection area 423 and the rectangular channel 1 is the area to be imaged, and the non-overlapping part 4232 of the annular edge detection area 423 and the rectangular channel 1 is air, which does not need to be calculated and reconstructed into an image. The amount of calculation is small. Therefore, the first sub-edge detector 421 and the second sub-edge detector 422 only need a small number of crystal modules 43 to form an image of this thickness. In this embodiment, the overlapping portion 4231 of the annular edge detection area 423 and the rectangular channel 1 is not larger than the non-overlapping portion 4232 of the annular edge detection area 423 and the rectangular channel 1, that is, detecting the four sharp corner areas of the rectangular channel 1. Compared with the intermediate detector 41, the amount of data that the edge detector 42 needs to calculate is reduced by more than half. Therefore, the number of rows of crystal modules 43 on the first sub-edge detector 421 and the number of rows of crystal modules 43 on the second sub-edge detector 422 can be set to half the number of rows of crystal modules 43 on the intermediate detector 41. When the number of rows on the first sub-edge detector 421 and the second sub-edge detector 422 is reduced, the spacing of the crystal modules 43 can be relatively increased, reducing the processing difficulty of the first sub-edge detector 421 and the second sub-edge detector 422, thereby reducing the production cost.

[0047] Furthermore, such as Figures 1-3 As shown, since the first sub-edge detector 421 and the second sub-edge detector 422 are symmetrically arranged on both sides of the middle detector 41, and the detection positions of the first sub-edge detector 421 and the second sub-edge detector 422 are the same annular edge detection area 423, in order to ensure the imaging effect of this annular edge detection area 423, the crystal module 43 of the first sub-edge detector 421 and the crystal module 43 of the second sub-edge detector 422 are staggered along the Z direction and have no overlapping positions. The crystal module 43 of the first sub-edge detector 421 and the crystal module 43 of the second sub-edge detector 422 are equivalent to twice the actual size. Figure 2 and Figure 3 As shown, the sum of the number of data layers acquired by the crystal module 43 of the first sub-edge detector 421 and the number of data layers acquired by the crystal module 43 of the second sub-edge detector 422 is equal to the number of data layers acquired by the crystal module 43 of the first sub-edge detector 421, which satisfies the imaging requirements of the CT system to form a CT image.

[0048] It should be noted that, as Figure 1As shown, the edge annular detection area formed between the X-ray source 3 and the edge detector 42 is existing technology. Specifically, based on the two edges of the X-ray path 44 irradiated by the X-ray source 3 onto the edge detector 42, an external circle is drawn to form two tangent points. The center of the external circle is on the axis of the rotating frame 21. The line connecting the two tangent points rotates around the axis of the rotating frame 21 to form the edge annular detection area.

[0049] In this embodiment, as Figure 1 As shown, the intermediate detector 41 is disposed on the first arc surface, and the edge detector 42 is disposed on the second arc surface. The first and second arc surfaces are coaxially arranged, and the X-ray source 3 is disposed on the axis of the first and second arc surfaces to meet the imaging requirements of the CT system. Mounting plates are provided at corresponding positions on the first and second arc surfaces, allowing the intermediate detector 41 and the edge detector 42 to be mounted.

[0050] Furthermore, the second arc surface does not interfere with the rectangular channel 1, preventing the edge detector 42 from interfering with the rectangular channel 1 when rotating around it, and the second arc surface does not exceed the outer diameter of the rotating frame 21.

[0051] In this embodiment, the radius of the second arc surface is smaller than the radius of the first arc surface. By placing the edge detector 42 on a smaller arc radius, the rotation radius of the frame 21 is reduced, thereby decreasing the size of the CT system. In other embodiments, the radius of the second arc surface can also be larger than the radius of the first arc surface, thereby increasing the spacing of the crystal modules 43 on the edge detector 42 and reducing the manufacturing difficulty and cost of the edge detector 42.

[0052] Furthermore, such as Figures 2-4 As shown, the radius of the first arc surface is Ra, the radius of the second arc surface is Rb, and the length of the intermediate detector 41 is Da, where Ra / Rb = Da / Db, thus meeting the imaging requirements of the CT system. After selecting the positions of the first and second arc surfaces, Ra, Rb, and Da are all known values, and Db can be calculated using Ra / Rb = Da / Db.

[0053] The spacing between the crystal modules 43 on the intermediate detector 41 is da, and the spacing between the crystal modules 43 on the first sub-edge detector 421 and the second sub-edge detector 422 is db. The first sub-edge detector 421 has N rows of crystal modules 43, and the intermediate detector 41 has 2N rows of crystal modules 43, where Db = db * (N-1) and Da = da * (2N-1). After calculating Db, db can be calculated using Db = db * (N-1), and da can be calculated using Da = da * (2N-1). N is a natural number, and the value of N is based on existing technology and can be set according to detection requirements.

[0054] More preferably, the crystal module 43 of the first sub-edge detector 421 and the crystal module 43 of the second sub-edge detector 422 are spaced apart by 1 / 2 dB along the Z direction, and the data layer formed by the crystal module 43 of the first sub-edge detector 421 and the crystal module 43 of the second sub-edge detector 422 is spaced together, which improves the image quality and reduces the computational difficulty.

[0055] Preferably, such as Figure 1 As shown, the ray path 44 of the ray source 3 irradiating the edge detector 42 and the ray path 44 of the ray source 3 irradiating the middle detector 41 are adjacent to each other, so as to prevent gaps between the ray paths 44 and thus meet the imaging requirements of the CT system.

[0056] More preferably, such as Figure 5 As shown, there are multiple sets of edge detectors 42 and multiple second arc surfaces. Each set of edge detectors 42 corresponds one-to-one with a different second arc surface. These edge detectors 42 can be mounted on second arc surfaces at different layers, further reducing the size of the CT system. The theoretical imaging area and actual location area of ​​different sets of edge detectors 42 also differ in shape and area ratio; therefore, different configurations can be selected for different sets of edge detectors 42.

[0057] like Figure 6 As shown, this embodiment also provides a security inspection device, including the aforementioned CT system. The rotating assembly 2 further includes a frame 22, and the security inspection device also includes a conveyor belt 5 and a data transmission assembly 6. The rotating frame 21 is rotatably connected to the frame 22, the conveyor belt 5 is disposed within the rectangular channel 1, and the object to be inspected 10 is mounted on the conveyor belt. The data transmission assembly 6 performs calculations and imaging based on the detection information from the CT system. It should be noted that this CT system can also be used in CT imaging devices and other equipment used for CT imaging.

[0058] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A CT system, characterized in that, include: A rectangular channel extending along the Z direction (1); The rotating assembly (2) includes a rotating frame (21) which is arranged around the rectangular channel (1). The X-ray source (3) and the detector assembly (4) are mounted on the rotating frame (21), and the X-ray source (3) and the detector assembly (4) are located on both sides of the rectangular channel (1); The detector assembly (4) includes an intermediate detector (41) and an edge detector (42). The edge detector (42) includes a first sub-edge detector (421) and a second sub-edge detector (422) symmetrically arranged on both sides of the intermediate detector (41). The rays from the X-ray source (3) pass through the rectangular channel (1) and irradiate the detector assembly (4). When the rotating frame (21) rotates 360 degrees, an annular edge detection area (423) for detecting the rectangular channel (1) is formed between the X-ray source (3) and the edge detector (42). The overlapping part (4231) of the annular edge detection area (423) and the rectangular channel (1) is not greater than the non-overlapping part (4232) of the annular edge detection area (423) and the rectangular channel (1). The intermediate detector (41), the first sub-edge detector (421), and the second sub-edge detector (422) are all uniformly spaced along the Z direction with multiple rows of crystal modules (43). The number of rows of crystal modules (43) on the first sub-edge detector (421) is the same as the number of rows of crystal modules (43) on the second sub-edge detector (422), and the number of rows of crystal modules (43) on the first sub-edge detector (421) is half the number of rows of crystal modules (43) on the intermediate detector (41). The crystal module (43) of the first sub-edge detector (421) and the crystal module (43) of the second sub-edge detector (422) are staggered along the Z direction and have no overlapping positions; The intermediate detector (41) is disposed on the first arc surface, the edge detector (42) is disposed on the second arc surface, the first arc surface and the second arc surface are coaxially disposed, and the radiation source (3) is disposed on the axis of the first arc surface and the second arc surface; The ray path (44) from the ray source (3) to the edge detector (42) overlaps on the adjacent side of the ray path (44) from the ray source (3) to the middle detector (41).

2. The CT system according to claim 1, characterized in that, The second arc surface does not interfere with the rectangular channel (1), and the second arc surface does not exceed the outer diameter of the rotating frame (21).

3. The CT system according to claim 2, characterized in that, The radius of the second arc surface is smaller than the radius of the first arc surface.

4. The CT system according to claim 1, characterized in that, The radius of the first arc surface is Ra, the radius of the second arc surface is Rb, the length of the intermediate detector (41) is Da, and the length of the edge detector (42) is Db, where Ra / Rb=Da / Db.

5. The CT system according to claim 4, characterized in that, The spacing of the crystal modules (43) on the intermediate detector (41) is da, the spacing of the crystal modules (43) on the first sub-edge detector (421) and the spacing of the crystal modules (43) on the second sub-edge detector (422) are both db, and the first sub-edge detector (421) is provided with N rows of crystal modules (43), and the intermediate detector (41) is provided with 2N rows of crystal modules (43), where Db=db*(N-1) and Da=da*(2N-1).

6. The CT system according to claim 5, characterized in that, The crystal module (43) of the first sub-edge detector (421) and the crystal module (43) of the second sub-edge detector (422) are spaced 1 / 2 dB apart along the Z direction.

7. The CT system according to claim 1, characterized in that, The edge detectors (42) are in multiple groups, and the second arc surface is in multiple groups, with each group of edge detectors (42) corresponding to one of the multiple second arc surfaces.

8. A security inspection device, characterized in that, Includes the CT system as described in any one of claims 1-7.

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