Imaging system and method for radiographic inspection

Abstract

The invention relates to an imaging system and method for radiographic inspection. An imaging system for radiographic inspection includes: an inspection region including an imaging region; all first target spots of the first radiation source assembly are arranged in a first radiation source plane; a plurality of first detector units of the first detector assembly are arranged in a detector plane, and the detector plane and the first ray source plane are spaced by a preset distance in the advancing direction of the inspected object; the ray source control device is configured to enable the first ray source assembly to simultaneously emit X-rays to the imaging area from the at least two first target spots at the same moment when the region of interest of the inspected object is at least partially located in the imaging area; in at least two first target spots which emit X-rays to the imaging area at the same time of the first ray source assembly, the ray emission range of each first target spot can cover the imaging area, and the first detector crystals corresponding to the ray emission ranges of any two first target spots do not coincide with each other.

Description

[0001] This application is a divisional application based on the invention with application number 202111204463.6, application date October 15, 2021, and applicants being Tsinghua University and Nuctech Technology Co., Ltd., and entitled “Imaging system and method for radiographic inspection”. Technical Field

[0002] The invention relates to the technical field of fluoroscopic imaging, and in particular to an imaging system for ray inspection. Background Art

[0003] CT (Computed Tomography) scanning systems are widely used in the fields of medical, security inspection and industry. CT scanning generates three-dimensional scanned images and has high recognition capabilities. According to the movement of the radiation source relative to the object being inspected during the scanning process, existing CT scanning systems can include dynamic spiral CT scanning systems and static CT scanning systems.

[0004] In existing CT scanning systems, whether it is a dynamic spiral CT scanning system or a static CT scanning system, the X-ray emission range of the ray source usually needs to cover the entire object to be inspected, that is, the object to be inspected is scanned and imaged as a whole, and these CT scanning systems only have a single target point emitting X-rays at the same time. For example, the existing static CT scanning system can use a single distributed ray source and a set of detector systems, or can use multiple distributed ray sources and a shared set of detector systems. However, the same set of detector systems can only receive X-rays from one target point at the same time. Therefore, the scanning speed of these CT scanning systems is limited by the rotation speed of the slip ring used in dynamic spiral scanning and the ray emission frequency of the ray source. In a static CT scanning system, the scanning speed is also limited by the ray emission frequency of the ray source. However, in some application scenarios, only the region of interest (ROI) of the object to be inspected needs to be paid attention to, and the scanning speed requirement is high, such as ROI imaging of a living body. In order to increase the sampling frequency of the CT scanning system, usually only an additional detector system can be added, but this will greatly increase the size and cost of the CT scanning system.

[0005] Therefore, there is a need for an improved imaging system and method. Summary of the invention

[0006] An object of the present invention is to provide an imaging system and method capable of scanning only a region of interest. An object of the present invention is to provide an imaging system and method capable of increasing the frequency of beam emission. An object of the present invention is to provide an imaging system and method capable of reducing the size and cost of the device. An object of the present invention is to provide an imaging system and method capable of better solving problems within CT. An object of the present invention is to provide an imaging system and method capable of reducing the influence of scattered signals.

[0007] One aspect of the present invention provides an imaging system for radiographic inspection, comprising: an inspection area, wherein an inspected object can enter the inspection area, the inspection area includes an imaging area, a region of interest of the inspected object can enter the imaging area, and the region of interest is a local region of the inspected object; a first ray source assembly, for emitting X-rays, wherein the first ray source assembly comprises a plurality of distributed ray sources, each of which comprises a plurality of first target points, and all the first target points of the first ray source assembly are arranged in a first ray source plane; a first detector assembly, for receiving X-rays emitted from the first ray source assembly and transmitted through the imaging area of ​​the imaging system, wherein the first detector assembly comprises a plurality of first detector units, each of which comprises a plurality of first target points; A first detector unit includes a plurality of first detector crystals, the plurality of first detector units are arranged in a detector plane, the detector plane and the first ray source plane are spaced apart from each other by a predetermined distance along the traveling direction of the inspected object; and a ray source control device, which is configured to enable the plurality of distributed ray sources of the first ray source assembly to simultaneously emit X-rays from at least two first target points to the imaging area at the same time when the region of interest is at least partially located in the imaging area, wherein, among the at least two first target points that simultaneously emit X-rays to the imaging area in the first ray source assembly, the ray emission range of each first target point can cover the imaging area, and the first detector crystals corresponding to the ray emission ranges of any two first target points do not overlap with each other.

[0008] According to certain embodiments of the present invention, the imaging system also includes a carrying device for carrying the object to be inspected, wherein the imaging system is configured such that the first ray source assembly and the first detector assembly can move along a travel direction relative to the carrying device so that a region of interest of the object to be inspected can enter the imaging area.

[0009] According to some embodiments of the present invention, the carrying device is configured to be able to transport the inspected object along a traveling direction.

[0010] According to some embodiments of the present invention, the carrying device is further configured to adjust the position of the region of interest of the inspected object relative to the imaging region so that the region of interest of the inspected object is located within the imaging region.

[0011] According to some embodiments of the present invention, the imaging area is located between the first ray source plane and an outer edge of the first detector assembly away from the first ray source assembly, wherein the imaging area is defined to be sufficient to accommodate the region of interest.

[0012] According to some embodiments of the present invention, the imaging region is defined as a cylindrical region having a central axis.

[0013] According to some embodiments of the invention, the direction of travel is substantially parallel to the central axis.

[0014] According to some embodiments of the present invention, the detector plane and the first ray source plane are parallel to each other.

[0015] According to some embodiments of the present invention, the plurality of distributed radiation sources of the first radiation source assembly are configured to have a combined extension angle greater than 180 degrees around the imaging area when viewed along the traveling direction.

[0016] According to some embodiments of the present invention, the plurality of distributed radiation sources of the first radiation source assembly are configured to extend completely around the imaging area to form a first radiation source ring.

[0017] According to some embodiments of the present invention, the radiation emission range of each first target point of the first radiation source assembly is selected to be insufficient to cover the examination area.

[0018] According to some embodiments of the present invention, each first target point of the first ray source assembly is arranged to be deflected by a first deflection angle along the traveling direction toward the first detector unit of the first detector assembly.

[0019] According to some embodiments of the present invention, the first deflection angle is between 1 degree and 5 degrees.

[0020] According to certain embodiments of the present invention, when viewed along the traveling direction, the first ray source assembly is configured to be rotatable within a predetermined range relative to the supporting device to adjust the position of the region of interest of the inspected object relative to the imaging region so that the region of interest of the inspected object is located within the imaging region.

[0021] According to certain embodiments of the present invention, the first radiation source assembly also includes at least one second target point, and the radiation emission range of the second target point is selected to cover the inspection area, wherein the radiation source control device is further configured to: when the first target point of the first radiation source assembly emits X-rays, the second target point does not emit X-rays, and when the second target point of the first radiation source assembly emits X-rays, the first target point does not emit X-rays.

[0022] According to certain embodiments of the present invention, the first ray source assembly includes multiple second target points, wherein the ray source control device is configured to enable the first ray source assembly to simultaneously emit X-rays from at least two second target points to the inspection area at the same time, wherein, among the at least two second target points from which the first ray source assembly simultaneously emits X-rays to the inspection area, the first detector crystals corresponding to the ray emission ranges of any two second target points do not overlap with each other.

[0023] According to some embodiments of the present invention, the first detector assembly is arranged to be located radially inward of the first ray source assembly when viewed along the traveling direction.

[0024] According to some embodiments of the present invention, the first detector assembly is configured to extend completely around the imaging region to constitute a detector ring.

[0025] According to some embodiments of the present invention, the first detector unit of the first detector assembly includes a single row of first detector crystals or a plurality of rows of first detector crystals.

[0026] According to some embodiments of the present invention, the imaging system further comprises a second detector assembly for receiving X-rays scattered from the inspected object, wherein the second detector assembly comprises a plurality of second detector units, each of which comprises a plurality of second detector crystals.

[0027] According to some embodiments of the present invention, the plurality of second detector units of the second detector assembly are arranged corresponding to the plurality of first detector units of the first detector assembly.

[0028] According to some embodiments of the present invention, the imaging system further comprises a shielding member arranged so that the second detector unit does not receive direct X-rays emitted from the first ray source assembly.

[0029] According to some embodiments of the present invention, along the traveling direction, the second detector crystals of each second detector unit are arranged to be spaced apart from the first detector crystals of the corresponding first detector unit so that the second detector unit does not receive direct X-rays emitted from the first ray source assembly.

[0030] According to some embodiments of the present invention, the number of second detector crystals in each second detector unit is equal to the number of first detector crystals in the corresponding first detector unit; or the number of second detector crystals in each second detector unit is less than the number of first detector crystals in the corresponding first detector unit.

[0031] According to some embodiments of the present invention, the imaging system further includes: a second ray source assembly for emitting X-rays, wherein the second ray source assembly includes a plurality of distributed ray sources, each distributed ray source includes a plurality of third target points, all the third target points of the second ray source assembly are arranged in the second ray source plane, and the detector plane is spaced apart from the second ray source plane by a predetermined distance along the direction of travel, wherein the first detector assembly is further configured to receive X-rays emitted from the second ray source assembly and transmitted through an imaging area of ​​the imaging system, wherein the first ray source plane, the detector plane, and the second ray source plane are sequentially distributed along the direction of travel, wherein the ray source control device is configured to enable the second ray source assembly to simultaneously emit X-rays from at least two third target points to the imaging area at the same time when the area of ​​interest is at least partially located in the imaging area, wherein among the at least two third target points of the second ray source assembly that simultaneously emit X-rays to the imaging area, the ray emission range of each third target point can cover the imaging area, and the first detector crystals corresponding to the ray emission ranges of any two third target points do not overlap with each other.

[0032] According to some embodiments of the present invention, the imaging system is configured such that the first ray source assembly, the first detector assembly, and the second ray source assembly can move relative to the carrying device along the travel direction so that the region of interest of the inspected object can enter the imaging area.

[0033] According to some embodiments of the present invention, the imaging region is located between the first ray source plane and the second ray source plane, wherein the imaging region is defined to be sufficient to accommodate the region of interest.

[0034] According to some embodiments of the present invention, the imaging region is defined as a cylindrical region having a central axis.

[0035] According to some embodiments of the present invention, the detector plane, the first ray source plane and the second ray source plane are parallel to each other.

[0036] According to certain embodiments of the present invention, the ray source control device is configured to cause at least one first target point of the first ray source assembly and at least one third target point of the second ray source assembly to simultaneously emit X-rays to the imaging area at the same time when the area of ​​interest of the inspected object is at least partially located in the imaging area, and wherein, when at least one first target point of the first ray source assembly and at least one third target point of the second ray source assembly simultaneously emit X-rays to the imaging area, the detector crystals of the first detector assembly corresponding to the ray emission range of the first target point of the first ray source assembly and the detector crystals of the first detector assembly corresponding to the ray emission range of the third target point of the second ray source assembly do not overlap with each other.

[0037] According to some embodiments of the present invention, the imaging system is further configured to reconstruct a three-dimensional scanned image of a region of interest of the inspected object based on the detection data of the first detector assembly.

[0038] Another aspect of the present invention provides an imaging method using an imaging system according to an embodiment of the present invention, comprising: (a) carrying an object to be inspected on a carrying device of the imaging system; and (b) moving a first ray source assembly and a first detector assembly of the imaging system relative to the carrying device along a travel direction so that a region of interest of the object to be inspected can enter an imaging region, while causing the first ray source assembly to emit X-rays and causing the X-rays to transmit through the imaging region and be received by the first detector assembly, wherein the step of causing the first ray source assembly to emit X-rays comprises: causing the first ray source assembly to simultaneously emit X-rays to the imaging region from at least two first target points at the same time, wherein, among the at least two first target points from which the first ray source assembly simultaneously emits X-rays to the imaging region, a ray emission range of each first target point can cover the imaging region, and first detector crystals corresponding to the ray emission ranges of any two first target points do not overlap with each other.

[0039] According to certain embodiments of the present invention, the imaging method further includes, after the inspected object is carried on a carrying device in step (a), adjusting the position of the inspected object's region of interest relative to the imaging region by the carrying device so that the inspected object's region of interest is located within the imaging region.

[0040] According to certain embodiments of the present invention, the imaging method further includes, after the inspected object is carried on a carrying device in step (a), observing along the direction of travel, causing the first radiation source assembly to rotate within a predetermined range relative to the carrying device to adjust the position of the inspected object's region of interest relative to the imaging area, so that the inspected object's region of interest is located within the imaging area.

[0041] According to certain embodiments of the present invention, the step of the first ray source assembly emitting X-rays also includes: emitting X-rays from a second target point of the first ray source assembly, the ray emission range of the second target point being selected to be able to cover the inspection area, wherein when the first target point of the first ray source assembly emits X-rays, the second target point does not emit X-rays, and when the second target point of the first ray source assembly emits X-rays, the first target point does not emit X-rays.

[0042] According to certain embodiments of the present invention, the radiation source assembly of the imaging system can emit X-rays from multiple target points at the same time, thereby increasing the radiation emission frequency of the imaging system, especially increasing the radiation emission frequency without increasing the volume occupied by the imaging system and the cost of additional detectors. By making the radiation emission range of the target points of the radiation source assembly only cover the imaging area, the imaging system can only perform transmission imaging of the imaging area and the area of ​​interest of the inspected object located therein, thereby reducing the volume occupied by the imaging system and the cost. By making the detector crystals corresponding to the simultaneously emitted targets non-overlapping with each other, it is possible to perform non-interfering signal acquisition while beams are emitted from multiple targets at the same time, which can help image reconstruction and improve the efficiency of transmission scanning. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a schematic diagram of an imaging system according to some embodiments of the present invention.

[0044] Figure 2 is a cross-sectional schematic diagram of an imaging system according to some embodiments of the present invention.

[0045] Figure 3 is a schematic diagram of ray emission of an imaging system according to some embodiments of the present invention.

[0046] Figure 4 is a partial cross-sectional schematic diagram of an imaging system according to some embodiments of the present invention.

[0047] Figure 5 is a schematic diagram of a first detector assembly and a second detector assembly according to some embodiments of the present invention.

[0048] Figure 6 is a schematic diagram of a first detector assembly and a second detector assembly according to some embodiments of the present invention.

[0049] Figure 7 is a schematic diagram of a first detector assembly and a second detector assembly according to some embodiments of the present invention.

[0050] Figure 8 is a partial cross-sectional schematic diagram of an imaging system including a second detector assembly and a shield according to some embodiments of the present invention.

[0051] Fig. 9 is a partial cross-sectional schematic diagram of an imaging system including a second detector assembly and a shield according to some embodiments of the present invention.

[0052] Fig.10 is a partial cross-sectional schematic diagram of an imaging system including a second detector assembly and a shield according to some embodiments of the present invention.

[0053] Fig.11 is a schematic cross-sectional view of an imaging system including a second radiation source assembly according to some embodiments of the present invention. DETAILED DESCRIPTION

[0054] Hereinafter, embodiments of the present invention are described with reference to the accompanying drawings. The following detailed description and the accompanying drawings are used to exemplarily illustrate the principles of the present invention, and the present invention is not limited to the preferred embodiments described. The scope of the present invention is defined by the claims. The present invention is now described in detail with reference to exemplary embodiments, and some embodiments are illustrated in the accompanying drawings. The following description is made with reference to the accompanying drawings, and unless otherwise indicated, the same reference numerals in different drawings represent the same or similar elements. The schemes described in the following exemplary embodiments do not represent all schemes of the present invention. On the contrary, these schemes are merely examples of systems and methods of various aspects of the present invention involved in the appended claims.

[0055] The imaging system and imaging method for radiographic inspection according to the embodiments of the present invention can be applied to fields such as medical treatment, security inspection, and industry, and can be used for performing perspective imaging inspection on objects or human bodies.

[0056] Figure 1 is a schematic diagram of an imaging system according to some embodiments of the present invention. Figure 2 is a cross-sectional schematic diagram of an imaging system according to some embodiments of the present invention. Figure 3 is a schematic diagram of ray emission of an imaging system according to some embodiments of the present invention.

[0057] According to some embodiments of the present invention, Figure 1 As shown, the imaging system for radiographic inspection includes: an inspection area 100, a first ray source assembly 200, and a first detector assembly 300. The first ray source assembly 200 is used to emit X-rays. The first detector assembly 300 is used to receive X-rays emitted from the first ray source assembly 200 and transmitted through the inspection area 100 of the imaging system. According to some embodiments of the present invention, the first ray source assembly 200 and the first detector assembly 300 are arranged to surround the inspection area 100, that is, located radially outside the inspection area 100. The imaging system is configured so that the first ray source assembly 200 and the first detector assembly 300 can move along the travel direction relative to the object to be inspected.

[0058] According to some embodiments of the present invention, the imaging system defines an inspection area 100. In this document, "inspection area" means an area that an inspected object can enter. When the inspected object is located in the inspection area 100, the X-rays emitted from the first ray source assembly 200 can penetrate the inspected object and be received by the first detector assembly 300. In an exemplary embodiment, the inspection area 100 includes a first end and a second end. In some embodiments, the inspected object is conveyed into the inspection area 100 from one of the first end and the second end, and leaves the inspection area 100 from the other.

[0059] According to some embodiments of the present invention, the object to be inspected includes a region of interest (ROI), which is a local region of the object to be inspected. For example, when the object to be inspected is a human body, the region of interest may be a local region of the human body such as the heart and lungs. According to some embodiments of the present invention, the inspection region 100 includes an imaging region 110 having a central axis, that is, the imaging region 110 is a local region of the inspection region 100. In this article, the "imaging region" means an area where the region of interest of the object to be inspected can enter and receive X-ray transmission inspection. The size of the imaging region 110 is set to be sufficient to accommodate the region of interest of the object to be inspected. In this article, the central axis of the imaging region means the axis of the approximate center of the cross section perpendicular to the direction of travel (described below) passing through the imaging region. In some embodiments, the inspection region and the imaging region are fixed relative to the first detector assembly 300 (and the second detector assembly 600 described below). In some embodiments, the inspection region and the imaging region are fixed relative to the first ray source assembly 200 and the first detector assembly 300 (and the second ray source assembly 700 and the second detector assembly 600 described below).

[0060] In an exemplary embodiment, if Figure 1 As shown, the imaging system further includes a carrying device 400 for carrying the inspected object. According to some embodiments of the present invention, the first ray source assembly 200 and the first detector assembly 300 can move relative to the carrying device 400 along the travel direction. As a result, the region of interest of the inspected object can enter the imaging area 110 of the inspection area 100. In an exemplary embodiment, the carrying device 400 is used to transport the inspected object into the inspection area 100 along the travel direction. In an exemplary embodiment, the travel direction is parallel to the horizontal direction. According to some embodiments of the present invention, the carrying device 400 can reciprocally transport the inspected object through the inspection area 100 along the travel direction, that is, transport the inspected object back and forth in opposite directions. In some embodiments, the carrying device 400 transports the inspected object in a uniform linear motion. In an exemplary embodiment, the travel direction is substantially parallel to the central axis of the imaging area 110. In some embodiments, the carrying device 400 is a conveyor belt or a loading platform.

[0061] According to some embodiments of the present invention, Figure 1 As shown, the imaging system may further include a shielding component 500. In an exemplary embodiment, the shielding component 500 may be arranged to surround the examination region 100 of the imaging system. In an exemplary embodiment, the first ray source assembly 200 and the first detector assembly 300 are arranged to surround the examination region 100 and are located outside the shielding component 500, i.e., on a side of the shielding component 500 away from the examination region 100.

[0062] Herein, “axial” means a direction parallel to the direction of travel, “radial” means a direction radiating outward from a central axis in a plane perpendicular to the direction of travel, and “circumferential” means a direction in a plane perpendicular to the direction of travel and perpendicular to the “radial”.

[0063] The structure and arrangement of the first ray source assembly and the first detector assembly according to some embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0064] According to some embodiments of the present invention, the first ray source assembly 200 includes a plurality of distributed ray sources 210, each of which includes a plurality of first targets. In some embodiments, each distributed ray source 210 includes a separate housing to define a separate vacuum space, and includes a plurality of first targets encapsulated in the housing. In some embodiments, the plurality of first targets of each distributed ray source 210 has a uniform target spacing. In some embodiments, the plurality of first targets of each distributed ray source 210 are distributed along a straight line.

[0065] As described above, when the first ray source assembly 200 includes a plurality of distributed ray sources 210, each distributed ray source 210 defines a separate vacuum space, and thus does not share the vacuum space with other distributed ray sources 210. The vacuum spaces of different distributed ray sources 210 are not connected. According to some embodiments of the present invention, each distributed ray source 210 can be removed and / or installed in the imaging system independently of other distributed ray sources 210.

[0066] The above description states that the multiple first target points in the distributed ray source 210 have a uniform target point spacing. However, the present invention is not limited thereto. In some embodiments, the multiple first target points in the distributed ray source 210 may also be arranged non-uniformly, that is, have a non-uniform target point spacing.

[0067] It is described above that the multiple first target points in each distributed ray source 210 are arranged along a straight line. However, the present invention is not limited thereto. In some embodiments, the multiple first target points in the distributed ray source 210 may also be arranged along an arc line, a broken line, or the like.

[0068] According to some embodiments of the present invention, all first target points of the plurality of distributed ray sources 210 of the first ray source assembly 200 are arranged in the same plane (hereinafter referred to as the "first ray source plane"), that is, the plurality of distributed ray sources 210 of the first ray source assembly 200 are arranged in the same plane. In this article, "the target points are located in the same plane" means that the beam exit points of the target points are all located in the same plane. In some embodiments, the first ray source plane is substantially perpendicular to the traveling direction (or the central axis).

[0069] In an exemplary embodiment, the multiple distributed radiation sources 210 of the first radiation source assembly 200 completely extend around the imaging area 110, that is, the angle of continuous extension around the imaging area 110 observed along the traveling direction substantially reaches 360°. Thus, the multiple distributed radiation sources 210 of the first radiation source assembly 200 form a complete and continuous first radiation source ring. In some embodiments, the first radiation source ring can be a circular ring, a square ring, a rectangular ring, a polygonal ring, etc. For example, Figure 1 As shown, the plurality of first distributed ray sources 210 of the first ray source assembly 200 form a polygonal ring.

[0070] It is described above that the multiple distributed ray sources 210 of the first ray source assembly 200 form a complete ray source ring. However, the present invention is not limited thereto. In some embodiments, the ray source ring formed by the multiple distributed ray sources 210 of the first ray source assembly 200 may be incomplete, that is, there is a gap portion. In some embodiments, the multiple distributed ray sources 210 of the first ray source assembly 200 are divided into multiple segments, and the distributed ray sources 210 of different segments can be distributed at intervals around the imaging area 110. In an exemplary embodiment, when observed along the traveling direction, the multiple distributed ray sources 210 of the first ray source assembly 200 have a combined extension angle greater than 180 degrees relative to the central axis around the imaging area 110. In this article, the extension angle of each distributed ray source 210 relative to the central axis around the imaging area 110 represents the angle range of all first target points of the distributed ray source 210 relative to the imaging area 110 (relative to the central axis of the imaging area 110). When the first ray source assembly 200 includes multiple distributed ray sources 210, the multiple distributed ray sources 210 at different scanning positions relative to the imaging area 110 can provide a combined extension angle. Herein, the “combined extension angle” refers to the angle range generated by combining the extension angles of the multiple distributed ray sources 210 at different scanning positions relative to the imaging area 110. In some embodiments, the combined extension angles of the multiple distributed ray sources 210 at different scanning positions relative to the imaging area 110 may be continuous or discontinuous.

[0071] It is described above that the multiple distributed ray sources 210 of the first ray source assembly 200 form a ray source ring. However, the present invention is not limited to this. In some embodiments, the multiple distributed ray sources 210 of the first ray source assembly 200 may only partially extend continuously around the imaging area 110, that is, the multiple distributed ray sources 210 of the first ray source assembly 200 provide a continuous combined extension angle around the imaging area 110 relative to the central axis and the combined extension angle is less than 360°. In some embodiments, the continuous combined extension angle of the multiple distributed ray sources 210 of the first ray source assembly 200 around the imaging area 110 relative to the central axis is greater than 180° and less than 360°.

[0072] The first detector assembly 300 is used to receive X-rays emitted from the first ray source assembly 200 and transmitted through the imaging area 110 of the imaging system.

[0073] According to some embodiments of the present invention, the first detector assembly 300 includes a plurality of detector units 310. In some embodiments, the arrangement of the detector units in the first detector assembly 300 may be set according to factors such as the arrangement of the distributed ray sources 210 in the first ray source assembly 200 and / or the size of the inspected object. In some embodiments, the arrangement of the detector units in the first detector assembly 300 may also adopt a cost-effective arrangement, that is, to meet the imaging requirements with as few detector units as possible.

[0074] According to some embodiments of the present invention, each first detector unit 310 of the first detector assembly 300 includes a plurality of first detector crystals. In an exemplary embodiment, each detector unit 310 is arranged to not block the X-rays emitted by the distributed ray source 210 on the same side, but to receive the X-rays emitted by the distributed ray source 210 on other sides.

[0075] In an exemplary embodiment, a plurality of first detector units 310 are arranged in the same plane (hereinafter referred to as "detector plane"). In this article, "the detector units are arranged in the same plane" means that the center planes of the detector units (e.g., the center planes of the detector crystals) are all arranged in the same plane. For example, the center planes of the plurality of first detector units 310 are arranged in the same plane by the same positioning reference. In some embodiments, the detector plane is substantially perpendicular to the direction of travel (central axis). In some embodiments, the first detector unit 310 includes a single row of detector crystals or multiple rows of detector crystals.

[0076] In some embodiments, Figure 2As shown, along the central axis (or the traveling direction), the first ray source plane of the first ray source assembly 200 is spaced apart by a predetermined distance from the detector plane of the first detector assembly 300. In an exemplary embodiment, the first ray source plane of the first ray source assembly 200 is substantially parallel to the detector plane of the first detector assembly 300.

[0077] In an exemplary embodiment, the plurality of first detector units 310 of the first detector assembly 300 completely extend around the imaging region. Thus, the plurality of first detector units 310 form a complete and continuous first detector ring. In some embodiments, the first detector ring can be a circular ring, a square ring, a rectangular ring, a polygonal ring, etc. For example, Figure 1 As shown, the plurality of first detector units 310 form a ring.

[0078] It is described above that a plurality of first detector units 310 form a complete detector ring. However, the present invention is not limited thereto. In some embodiments, the detector ring formed by the plurality of first detector units 310 may be incomplete, i.e., there may be a gap. In some embodiments, the plurality of first detector units 310 are divided into multiple sections, and the first detector units 310 of different sections may be distributed at intervals around the imaging area.

[0079] Each first target point of the first ray source assembly 200 has a ray emission range. According to some embodiments of the present invention, the ray emission range of at least a portion of the first target points of the first ray source assembly 200 is selected to cover the imaging area 110. Herein, the ray emission range of the target point covers the imaging area 110, which means that the ray emission range of the target point can just cover the imaging area 110 or is slightly larger than the imaging area 110. The ray emission ranges of these first target points of the first ray source assembly 200 may cover the inspection area 100 or may not cover the inspection area 100. In some embodiments, the ray emission range of each of the first target points of the first ray source assembly 200 is selected to be insufficient to cover the inspection area 100, that is, the ray emission range of each of these first target points is smaller than the inspection area 100. In an exemplary embodiment, the ray emission range of each first target point of the first ray source assembly 200 can cover the imaging area 110, and optionally, the ray emission range of each first target point is insufficient to cover the inspection area 100. Compared with existing radiation sources whose radiation emission range covers the entire inspected object, the first radiation source assembly according to an embodiment of the present invention can provide a smaller radiation emission range to cover only the imaging area, so that transmission imaging can be performed only on the imaging area and the area of ​​interest of the inspected object.

[0080] According to certain embodiments of the present invention, the imaging area 110 is defined as being located between the first ray source plane of the first ray source assembly 200 and the outer edge of the first detector assembly 300 away from the first ray source assembly 200. In an exemplary embodiment, the imaging area 110 is defined as a cylindrical area. At this time, the central axis of the imaging area 110 is the rotation axis of the cylindrical area. In some embodiments, the imaging area 110 is defined as a region of interest sufficient to accommodate the object under inspection. In an exemplary embodiment, the imaging system is configured so that each point in the imaging area 110 can be passed through by the X-rays from the first ray source assembly 200 and the X-rays after passing through can be detected by the first detector assembly 300.

[0081] The relative positions of the first ray source assembly and the first detector assembly according to some embodiments of the present invention are described in detail below with reference to the accompanying drawings. Figure 4 is a partial cross-sectional schematic diagram of an imaging system according to some embodiments of the present invention.

[0082] According to some embodiments of the present invention, Figure 4 As shown, each first target point of the first ray source assembly 200 is configured to be deflected by a first deflection angle A1 along the direction of travel toward the first detector unit 310 of the first detector assembly 300. In some embodiments, the first deflection angle is between 1° and 5°. In some embodiments, each distributed ray source 210 is deflected around the axis of its first target point. In some embodiments, the first ray source assembly 200 may further include a collimator for deflecting the direction of the X-rays emitted by the distributed ray sources 210 of the first ray source assembly 200 by a first tilt angle along the direction of travel toward the first detector assembly 300.

[0083] In some embodiments, the first deflection angle is set so that the X-rays emitted by each distributed ray source 210 of the first ray source assembly 200 will not be blocked by the first detector assembly 300 before passing through the imaging area. In some embodiments, when the ray emission direction of the first ray source assembly 200 is deflected relative to the first detector assembly 300, the ray emission direction is not perpendicular to the central axis of the imaging area.

[0084] By deflecting the ray emission direction of the first ray source assembly 200 relative to the first detector assembly 300, the X-rays emitted by the distributed ray source 210 of the first ray source assembly 200 can avoid the detector unit 310 of the first detector assembly 300 on the same side, and can also be received by the detector unit 310 on other sides of the first detector assembly 200.

[0085] In some embodiments, the first detector assembly 300 is disposed radially inward of the first ray source assembly 200 when viewed along the traveling direction (or central axis). In other words, the first detector assembly 300 is disposed closer to the central axis of the imaging area 110 than the first ray source assembly 200.

[0086] In some embodiments, when viewed along the central axis (or the direction of travel), the carrier 400 is arranged to be located radially inward of the first detector assembly 300, and the first detector assembly 300 is arranged to be located radially inward of the first radiation source assembly 200. Figure 1 As shown, the first ray source assembly 200, the first detector assembly 300 and the carrying device 400 are arranged from outside to inside in sequence.

[0087] According to some embodiments of the present invention, the imaging system may also have a position adjustment function to adjust the position of the region of interest of the inspected object relative to the imaging area 110. For example, when the region of interest of the inspected object is not completely located in the imaging area 110, the region of interest of the inspected object may be moved to be completely located in the imaging area 110 through the position adjustment function.

[0088] In some embodiments, the carrying device 400 is configured to be able to adjust the position of the region of interest of the inspected object relative to the imaging region 110. In some embodiments, when viewed along the traveling direction, the first ray source assembly 200 is configured to be able to rotate within a predetermined range relative to the imaging region 110 (or the carrying device 400) to adjust the position of the region of interest of the inspected object relative to the imaging region 110. Thus, the region of interest of the inspected object can be located within the imaging region 110 through adjustment.

[0089] The ray emission control according to some embodiments of the present invention is described in detail below with reference to the accompanying drawings.

[0090] According to some embodiments of the present invention, the imaging system may further include a ray source control device (not shown). In some embodiments, the ray source control device may be configured to control the ray emission of the first ray source assembly 200, such as the target emission sequence, emission frequency, emission current, etc.

[0091] According to some embodiments of the present invention, the ray source control device is configured to make the multiple distributed ray sources 210 of the first ray source assembly 200 emit X-rays from at least two first target points to the imaging area 110 at the same time when the region of interest of the inspected object is at least partially located in the imaging area 110. As a result, there are more than two first target points in the first ray source plane of the first ray source assembly 200 that emit X-rays simultaneously. Therefore, the imaging system according to the embodiment of the present invention can increase the ray emission frequency, especially without increasing the volume occupied by the imaging system and the cost of the additional detector.

[0092] In some embodiments, the ray source control device is configured to control the first ray source assembly 200 to emit X-rays each time, so that the first ray source assembly 200 emits X-rays from at least two first target points simultaneously to the imaging area 110. In this case, each X-ray emission of the first ray source assembly 200 is a beam emission from multiple target points simultaneously.

[0093] In some embodiments, among the at least two first target points that simultaneously emit X-rays to the imaging area 110 by the first ray source assembly 200, the ray emission range of each first target point can cover the imaging area 110, and the detector crystals of the first detector assembly 300 corresponding to the ray emission ranges of any two first target points do not overlap with each other. By making the ray emission ranges of the first target points of the first ray source assembly 200 cover the imaging area 110, the imaging system can perform transmission imaging only on the imaging area 110 and the region of interest of the inspected object located therein, thereby reducing the volume and cost of the imaging system. By making the detector crystals corresponding to the first target points that emit simultaneously do not overlap with each other, signal acquisition without interference can be performed while beams are emitted from multiple targets at the same time, which can facilitate subsequent image reconstruction and improve the efficiency of transmission scanning. Figure 3 As shown, the first ray source assembly 200 can emit X-rays from six first target points simultaneously at the same time.

[0094] The following describes a radiation emission mode of the first radiation source assembly 200 of the imaging system according to some embodiments of the present invention.

[0095] In some embodiments, the first ray source assembly 200 includes a total of N first target points. All N first target points are divided into M groups, where M < N / 2. Each group includes the same number of first target points. The first target points in each group respectively come from different distributed ray sources 210. The first target points in each group do not overlap with each other (i.e., each first target point belongs to only one group). In each group, the detector crystals of the first detector assembly 300 corresponding to the ray emission ranges of the respective first target points do not overlap with each other. The ray source control device controls all the first target points in one group to simultaneously emit X-rays at the same moment, and causes the M groups of first target points to emit X-rays in sequence.

[0096] In some embodiments, the first ray source assembly 200 includes a total of N first target points. All N first target points are divided into M groups, where M < N / 2. Each group includes the same or different numbers of first target points, and each group includes at least one first target point (i.e., the number of first target points in each group can be one). The first target points in each group respectively come from different distributed ray sources 210. The first target points in each group do not overlap with each other (i.e., each first target point belongs to only one group). In each group, the detector crystals of the first detector assembly 300 corresponding to the ray emission ranges of the respective first target points do not overlap with each other. The ray source control device controls all the first target points in one group to simultaneously emit X-rays at the same moment, and causes the M groups of first target points to emit X-rays in sequence.

[0097] In some embodiments, the first ray source assembly 200 includes a total of N first target points. All N first target points are divided into M groups, where M < N / 2. Each group includes the same number of first target points. The first target points in each group respectively come from different distributed ray sources 210. The first target points in each group may partially overlap (i.e., one first target point can belong to two or more groups simultaneously). In each group, the detector crystals of the first detector assembly 300 corresponding to the ray emission ranges of the respective first target points do not overlap with each other. The ray source control device controls all the first target points in one group to simultaneously emit X-rays at the same moment, and causes the M groups of first target points to emit X-rays in sequence.

[0098] The above describes three ray emission modes of the imaging system by way of example. However, the present invention is not limited thereto. According to embodiments of the present invention, the imaging system may also have other ray emission modes. When there are two or more first target points in the first ray source plane of the first ray source assembly 200 that can simultaneously emit X-rays, the ray emission mode of the imaging system can be combined according to the number of groups of first target points in the first ray source assembly 200, the grouping attribution of each first target point, the emission intervals and sequences of the first target points in each group, etc., to achieve different modes of X-ray emission.

[0099] According to some embodiments of the present invention, the imaging system may also be configured to reconstruct a three-dimensional scan (CT) image of a region of interest of the inspected object based on the detection data of the first detector assembly 300. According to some embodiments of the present invention, the imaging system may use an iterative reconstruction algorithm, an analytical reconstruction algorithm, or a combination of different reconstruction algorithms when reconstructing a three-dimensional scan image of a region of interest of the inspected object.

[0100] When the ray emission range of the first target point of the first ray source assembly 200 only covers the region of interest and the region of interest is completely inside the object to be inspected, the projection data may be truncated. In this case, the imaging of the region of interest of the object to be inspected belongs to the CT internal problem. Compared with the image reconstruction when the ray emission range covers the entire object to be inspected, the CT internal problem has the problem of non-unique solution in theory.

[0101] In order to solve this problem, in some implementation cases, in addition to the above-mentioned first target point (also referred to as a small fan angle target point) whose ray emission range only covers the imaging area 110 but not the entire inspection area 100, the first ray source assembly 200 may also include a second target point (also referred to as a large fan angle target point) whose ray emission range can cover the inspection area 100.

[0102] According to some embodiments of the present invention, the first ray source assembly 200 further includes at least one second target (large fan angle target). The ray emission range of the second target is selected to cover the inspection area 100. In some embodiments, the first detector assembly 300 is also configured to receive X-rays emitted from the second target of the first ray source assembly 200 and transmitted through the inspection area 100. In an exemplary embodiment, when a distributed ray source 210 of the first ray source assembly 200 includes a second target, the distributed ray source 210 including both the first target and the second target can arrange its respective targets in the same manner as the distributed ray source 210 including only the first target.

[0103] In some embodiments, the ray source control device is configured to prevent the second target from emitting X-rays when the first target of the first ray source assembly 200 emits X-rays, and prevent the first target from emitting X-rays when the second target of the first ray source assembly 200 emits X-rays. Thus, the large fan angle target and the small fan angle target of the imaging system are separately emitting rays.

[0104] In some embodiments, the first radiation source assembly 200 includes a plurality of second target points. The radiation source control device is configured such that the first radiation source assembly 200 emits X-rays from at least two second target points to the examination area simultaneously at the same moment. In some embodiments, among at least two second target points of the first radiation source assembly 200 that emit X-rays to the examination area simultaneously, the first detector crystals corresponding to the radiation emission ranges of any two second target points do not overlap with each other. Thus, there can be more than two second target points of the first radiation source assembly 200 emitting X-rays simultaneously. In some embodiments, the plurality of second target points of the first radiation source assembly 200 are evenly distributed. For example, assume that the first radiation source assembly 200 includes a total of 9 target points, where the 1st, 4th, and 7th target points can be second target points, and the remaining 2nd, 3rd, 5th, 6th, 8th, and 9th target points can be the above-mentioned first target points.

[0105] The radiation emission mode of the first radiation source assembly 200 including second target points according to certain embodiments of the present invention is described below. In some embodiments, the first radiation source assembly 200 includes N1 first target points and N2 second target points. The radiation source control device can divide the N1 first target points into M groups (M < N1 / 2) with reference to any of the above radiation emission modes, and control the M groups of first target points and the N2 second target points to emit X-rays in a predetermined order. The radiation source control device is configured such that when the first target points of the first radiation source assembly 200 emit X-rays, the second target points do not emit X-rays, and when the second target points of the first radiation source assembly 200 emit X-rays, the first target points do not emit X-rays. In each group of first target points, the detector crystals of the first detector assembly 300 corresponding to the radiation emission ranges of the respective first target points do not overlap with each other. When the first radiation source assembly 200 emits X-rays from at least two second target points to the examination area 100 simultaneously at the same moment, the first detector crystals corresponding to the radiation emission ranges of the second target points that emit X-rays simultaneously do not overlap with each other.

[0106] By adopting the above configuration, large fan-angle target points can be used to image the entire object to be examined, which helps to avoid or solve internal problems of the CT; at the same time, small fan-angle target points can be used to improve the imaging quality of the region of interest.

[0107] According to the above embodiments, the plurality of first target points of the first radiation source assembly 200 can emit X-rays simultaneously, and optionally, the plurality of second target points of the first radiation source assembly 200 can also emit X-rays simultaneously. Since the X-rays emitted by the respective target points overlap and affect each other when multiple target points emit X-rays simultaneously, this may reduce the signal-to-noise ratio of the first detector assembly and thus affect the imaging quality.

[0108] In order to correct the scattered signal, according to some embodiments of the present invention, the imaging system may further include a second detector assembly 600 for receiving X-rays scattered from the object under inspection. According to some embodiments of the present invention, the second detector assembly 600 is arranged to surround the inspection area 100, that is, located radially outside the inspection area 100. In some embodiments, the second detector assembly 600 is fixed relative to the first detector assembly 300.

[0109] Figure 4 An imaging system including a second detector assembly according to some embodiments of the present invention is shown. In some embodiments, the second detector assembly 600 includes a plurality of second detector units 610. In an exemplary embodiment, the plurality of second detector units 610 of the second detector assembly 600 are arranged correspondingly to the plurality of first detector units 310 of the first detector assembly 300, preferably in one-to-one correspondence. According to some embodiments of the present invention, the second detector unit 610 is arranged not to receive direct X-rays emitted from the first ray source assembly 200, but to receive X-rays scattered by the object under inspection.

[0110] In an exemplary embodiment, each second detector unit 610 includes a plurality of second detector crystals. The second detector crystal 611 of each second detector unit 610 is arranged side by side with the first detector crystal 311 of the corresponding first detector unit 310. In this article, "arranged side by side" means that the corresponding first detector crystal and the second detector crystal are in approximately the same radial position and circumferential position when viewed in the direction of travel. Along the direction of travel (or the central axis), the corresponding second detector crystal 611 is arranged to contact or be spaced apart from the first detector crystal 311, which will be described in detail below with reference to the accompanying drawings.

[0111] In some embodiments, along the traveling direction (or central axis), the second detector crystals of each second detector unit 610 are arranged to be spaced apart from the first detector crystals of the corresponding first detector unit 310, so that the second detector unit 610 does not receive the direct X-rays emitted from the first ray source assembly 200. Thus, the second detector units 610 of the second detector assembly 600 are disposed outside the ray emission range of the first target point of the first ray source assembly 200.

[0112] Figure 5 is a schematic diagram of a first detector assembly and a second detector assembly according to some embodiments of the present invention. Figure 6 Schematic diagram of a first detector assembly and a second detector assembly according to some embodiments of the present invention. Figure 5 and Figure 6As shown, along the traveling direction (or the central axis), the second detector crystals 611 of the second detector unit are arranged to be spaced apart from the corresponding first detector crystals 311 of the first detector unit.

[0113] In some embodiments, along the traveling direction (or central axis), the second detector crystal of each second detector unit 610 is arranged to contact the first detector crystal of the corresponding first detector unit 310. In an exemplary embodiment, the imaging system further includes a shielding member, which is arranged so that the second detector unit 610 does not receive direct X-rays emitted from the first ray source assembly 200. Since the second detector crystal is arranged in close proximity to the first detector crystal, part of the direct X-rays may be received by the second detector crystal. By providing a shielding member, the second detector unit 610 can be prevented from receiving direct X-rays, so as to improve the detection accuracy of the second detector assembly and improve the detection accuracy of the corrected transmission X-ray signal.

[0114] Hereinafter, shielding members according to some embodiments of the present invention will be described with reference to the accompanying drawings.

[0115] Figure 7 is a schematic diagram of a first detector assembly and a second detector assembly according to some embodiments of the present invention. Figure 8 FIG. 4 is a partial cross-sectional schematic diagram of an imaging system including a second detector assembly and a shield according to some embodiments of the present invention. Figure 7 and Figure 8 As shown, the second detector crystal 611 of the second detector unit 610 is arranged adjacent to the first detector crystal 311 of the corresponding first detector unit 310 along the traveling direction. Along the traveling direction (or the central axis), the shielding member 620 is arranged between the second detector crystal 611 of the adjacent second detector unit 610 and the first detector crystal 311 of the first detector unit 310. In some embodiments, the shielding member 620 is arranged to be in direct contact with the second detector unit 610 and / or the second detector unit 310, for example, the radial inner surface ( Figure 8 The upper surface shown in ). Figure 7 and Figure 8 In the illustrated embodiment, the shielding member 620 is a vertical shielding member, that is, it extends substantially in the vertical direction when viewed along the circumferential direction.

[0116] Fig. 9 is a partial cross-sectional schematic diagram of an imaging system including a second detector assembly and a shield according to some embodiments of the present invention. Fig.10 FIG. 4 is a partial cross-sectional schematic diagram of an imaging system including a second detector assembly and a shield according to some embodiments of the present invention. Fig. 9 and Fig.10As shown, the second detector crystal of the second detector unit 610 is arranged closely to the first detector crystal of the corresponding first detector unit 310 along the traveling direction. The shielding member 620 is arranged to be spaced apart from the second detector unit 610 and the second detector unit 310, that is, not in direct contact. If necessary, the shielding member 620 can be arranged to be further away from the second detector unit 610 and the second detector unit 310 (such as Fig. 9 ), or closer to the second detector unit 610 and the second detector unit 310 (as shown Fig.10 ). Fig. 9 and Fig.10 In the illustrated embodiment, the shielding member 620 is a horizontal shielding member, that is, it extends substantially in a horizontal direction when viewed along the circumferential direction.

[0117] The above description is that a shielding member is provided when the second detector crystal 611 of the second detector unit 610 and the first detector crystal 311 of the corresponding first detector unit 310 contact each other along the traveling direction. However, the present invention is not limited thereto. It should be understood that a shielding member may also be provided when the second detector crystal 611 of the second detector unit 610 and the first detector crystal 311 of the corresponding first detector unit 310 are arranged to be spaced apart.

[0118] The above describes some embodiments of the shielding member by way of example. However, the present invention is not limited thereto. It should be understood that as long as the shielding member can prevent the second detector unit 610 from receiving direct X-rays, the shielding member can be arranged in any structure and form.

[0119] In some embodiments, Figure 5 and Figure 7 As shown, the number of second detector crystals 611 of each second detector unit is equal to the number of first detector crystals 311 of the corresponding first detector unit. Thus, for each column of first detector crystals 311 of the first detector unit 310, a column (at least one) of second detector crystals 611 for receiving scattered signals is correspondingly provided.

[0120] The following is an exemplary description of the scatter correction mode according to some embodiments of the present invention. Assuming that the readings of the first detector crystals 311 of each column of the first detector unit 310 are p1, p2, p3... and the readings of the second detector crystals 611 of each column of the second detector unit 610 are q, considering that the scatter signal is a low-frequency signal and the width of the detection crystal is small, the transmission X-ray signal after scatter correction can be expressed as p1-q, p2-q, p3-q...

[0121] In some embodiments, Figure 6As shown, the number of the second detector crystals 611 of each second detector unit is less than the number of the first detector crystals 311 of the corresponding first detector unit. For example, the second detector crystals 611 of the second detector unit 610 are arranged at intervals along the length direction of the first detector unit 310. For example, based on the readings of the second detector crystals 611 of each column, the calculated values ​​of the scattered signals of the first detector crystals 311 of each column where the second detector crystals 611 are not set can be obtained by interpolation or fitting, and the scattered signal correction is performed accordingly.

[0122] The above description is that the imaging system includes the first ray source assembly 200 in which the first target point is arranged in the first ray source plane. However, the present invention is not limited thereto. Fig.11 is a cross-sectional schematic diagram of an imaging system including a second radiation source assembly according to some embodiments of the present invention. Fig.11 As shown, the imaging system further includes a second ray source assembly 700 for emitting X-rays. When the imaging system includes the second ray source assembly 700, the first detector assembly 300 is further configured to receive X-rays emitted from the second ray source assembly 700 and transmitted through the examination region 100 (particularly the imaging region 110) of the imaging system. According to some embodiments of the present invention, when the object to be examined is located in the examination region 100, the X-rays emitted from the second ray source assembly 700 can penetrate the object to be examined and be received by the first detector assembly 300.

[0123] According to some embodiments of the present invention, the second ray source assembly 700 includes a plurality of distributed ray sources, each of which includes a plurality of third targets. Each distributed ray source of the second ray source assembly 700 may have the same structure, construction, and arrangement as the distributed ray source 210 of the first ray source assembly 200 according to any of the above embodiments. The third target of the second ray source assembly 700 may have the same structure, construction, and arrangement as the first target of the first ray source assembly 200 according to any of the above embodiments.

[0124] Each third target point of the second ray source assembly 700 has a ray emission range. According to some embodiments of the present invention, the ray emission range of at least a portion of the third target points of the second ray source assembly 700 is selected to cover the imaging area 110. In some embodiments, the ray emission range of each of the third target points of the second ray source assembly 700 is selected to be insufficient to cover the inspection area 100, that is, the ray emission range of each of these third target points is smaller than the inspection area 100. In an exemplary embodiment, the ray emission range of each third target point of the second ray source assembly 700 can cover the imaging area 110, and optionally, the ray emission range of each third target point is insufficient to cover the inspection area 100.

[0125] According to some embodiments of the present invention, all third target points of the multiple distributed radiation sources of the second radiation source assembly 700 are arranged in the same plane (hereinafter referred to as the "second radiation source plane"), that is, the multiple distributed radiation sources of the second radiation source assembly 700 are arranged in the same plane. In some embodiments, the second radiation source plane is substantially perpendicular to the direction of travel (or the central axis). In some embodiments, along the direction of travel (or the central axis), the second radiation source plane of the second radiation source assembly 700 is spaced apart from the detector plane of the first detector assembly 300 by a predetermined distance.

[0126] According to some embodiments of the present invention, the first ray source plane of the first ray source assembly 200, the detector plane of the first detector assembly 300, and the second ray source plane of the second ray source assembly 700 are sequentially distributed along the traveling direction (or the central axis). Fig.11 As shown, along the traveling direction (or central axis), the first ray source assembly 200 and the second ray source assembly 700 are respectively arranged on both sides of the first detector assembly 300. Thus, the imaging system according to some embodiments of the present invention has two ray source planes, which are respectively located on both sides of the detector plane.

[0127] In an exemplary embodiment, the first ray source plane, the detector plane and the second ray source plane are substantially parallel to each other. In some embodiments, the first ray source plane, the detector plane and the second ray source plane are substantially perpendicular to the traveling direction (or central axis).

[0128] According to some embodiments of the present invention, when the imaging system further includes a second ray source assembly 700, the imaging region 110 is defined as being located between a first ray source plane of the first ray source assembly 200 and a second ray source plane of the second ray source assembly 700. In an exemplary embodiment, the imaging region 110 is defined as a cylindrical region. In some embodiments, the imaging region 110 is defined as a region of interest sufficient to accommodate the object under examination.

[0129] According to some embodiments of the present invention, the first ray source assembly 200 , the first detector assembly 300 , and the second ray source assembly 700 are capable of moving together relative to the carrying device 400 along the traveling direction.

[0130] According to some embodiments of the present invention, each target point of the second ray source assembly 700 is configured to be deflected by a second deflection angle along the direction of travel toward the first detector unit 310 of the first detector assembly 300. In some embodiments, the second deflection angle is between 1 degree and 5 degrees. In some embodiments, each distributed ray source of the second ray source assembly 700 is deflected around the axis of its target point. In some embodiments, the second ray source assembly 700 may also include a collimator for deflecting the direction of the X-rays emitted by the distributed ray sources of the second ray source assembly 700 by a second tilt angle along the direction of travel toward the first detector assembly 300. In some embodiments, the second deflection angle is configured so that the X-rays emitted by each distributed ray source of the second ray source assembly 700 are not blocked by the first detector assembly 300 before passing through the imaging area.

[0131] It should be understood that since the first ray source assembly 200 and the second ray source assembly 700 are respectively disposed on both sides of the first detector assembly 300, the X-rays emitted by the first ray source assembly 200 and the X-rays emitted by the second ray source assembly 700 are deflected relative to each other. In an exemplary embodiment, the first deflection angle is equal to the second deflection angle.

[0132] According to some embodiments of the present invention, when the imaging system further includes a second ray source assembly 700 , the ray source control device is further used to control the ray emission of the second ray source assembly 700 .

[0133] In some embodiments, the ray source control device is configured to cause the multiple distributed ray sources of the second ray source assembly 700 to simultaneously emit X-rays from at least two third targets to the imaging area 110 at the same time when the region of interest of the inspected object is at least partially located in the imaging area 110. Among the at least two third targets that simultaneously emit X-rays to the imaging area 110 by the second ray source assembly 700, the ray emission range of each third target can cover the imaging area 110, and the detector crystals of the first detector assembly 300 corresponding to the ray emission ranges of any two third targets do not overlap with each other. Thus, there are more than two targets in the second ray source plane that simultaneously emit X-rays. According to some embodiments of the present invention, the ray source control device can be configured to control the ray emission of the second ray source assembly 700, such as the target emission sequence, emission frequency, emission current, etc.

[0134] According to some embodiments of the present invention, the ray source control device is configured to make at least one first target point of the first ray source assembly 200 and at least one third target point of the second ray source assembly 700 simultaneously emit X-rays to the imaging area 110 at the same time when the region of interest of the inspected object is at least partially located in the imaging area 110. In this case, the first ray source assembly 200 and the second ray source assembly 700 of the imaging system can emit X-rays from at least two targets (at least one first target point and at least one third target point). Therefore, the imaging system can further improve the ray emission frequency and scanning efficiency.

[0135] In some embodiments, when at least one first target of the first ray source assembly 200 and at least one third target of the second ray source assembly 700 simultaneously emit X-rays to the imaging area 110, the detector crystals of the first detector assembly 300 corresponding to the ray emission range of the first target of the first ray source assembly 200 and the detector crystals of the first detector assembly 300 corresponding to the ray emission range of the third target of the second ray source assembly 700 do not overlap with each other.

[0136] The above describes some exemplary structures, configurations and arrangements of the second ray source assembly 700 . However, the present invention is not limited thereto. It should be understood that any embodiment described herein involving the first ray source assembly 200 can be equally applied to the second ray source assembly 700 .

[0137] The imaging method according to some embodiments of the present invention is described in detail below. According to some embodiments of the present invention, any of the above-mentioned imaging systems can be used to implement the imaging method.

[0138] The imaging method according to some embodiments of the present invention is described below by taking the imaging system including the first ray source assembly 200 and the first detector assembly 300 as an example. However, it should be understood that the imaging system for implementing the imaging method according to the embodiment of the present invention may also include a second ray source assembly 700.

[0139] In step S10, the object to be inspected is carried on the carrying device 400 of the imaging system.

[0140] In step S20, the first ray source assembly 200 and the first detector assembly 300 are moved relative to the carrying device 400 along the travel direction so that the region of interest of the inspected object can enter the imaging region 110, and the first ray source assembly 200 emits X-rays and the X-rays pass through the imaging region 110 and are received by the first detector assembly 300. In some embodiments, the inspected object is transported along the travel direction by the carrying device 400.

[0141] During the process of the first ray source assembly 200 emitting X-rays, the multiple distributed ray sources 210 of the first ray source assembly 200 simultaneously emit X-rays from at least two first target points to the imaging area 110 at the same time. Among the at least two target points from which the first ray source assembly 200 simultaneously emits X-rays to the imaging area 110, the ray emission range of each target point can cover the imaging area 110, and the detector crystals of the first detector assembly 300 corresponding to the ray emission ranges of any two target points do not overlap with each other.

[0142] According to some embodiments of the present invention, the imaging method may also adjust the position of the region of interest of the inspected object relative to the imaging area 110 through the position adjustment function of the imaging system. For example, when the region of interest of the inspected object is not completely located in the imaging area 110, the region of interest of the inspected object may be moved to be completely located in the imaging area 110 through the position adjustment function of the imaging system.

[0143] In some embodiments, the imaging method further includes, after the inspected object is carried on the carrying device 400 in step S10, adjusting the position of the region of interest of the inspected object relative to the imaging region 110 by the carrying device 400. In some embodiments, the imaging method further includes, after the inspected object is carried on the carrying device 400 in step S10, observing along the traveling direction, by rotating the first ray source assembly 200 relative to the imaging region 110 (or the carrying device 400) within a predetermined range, so as to adjust the position of the region of interest of the inspected object relative to the imaging region 110. Thus, the imaging method can make the region of interest of the inspected object be located within the imaging region 110 through adjustment.

[0144] According to some embodiments of the present invention, the imaging method may also provide a second target (large fan angle target) whose ray emission range can cover the inspection area 100 to solve potential internal CT problems. It should be understood that any embodiment involving the second target in this article can be applied to the imaging method.

[0145] In some embodiments, the step of the first ray source assembly 200 emitting X-rays in the above step S20 further includes: emitting X-rays from a second target point of the first ray source assembly 200. The ray emission range of the second target point is selected to cover the inspection area 100. In some embodiments, when the first target point of the first ray source assembly 200 emits X-rays, the second target point does not emit X-rays, and when the second target point of the first ray source assembly 200 emits X-rays, the first target point does not emit X-rays.

[0146] According to some embodiments of the present invention, the imaging method may further include step S30: reconstructing a three-dimensional scan (CT) image of a region of interest of the inspected object based on the detection data of the first detector assembly 300. In some embodiments, the imaging method may further include identifying the inspected object and providing an identification result after reconstructing the three-dimensional scan image of the inspected object. In some embodiments, the imaging method may further include displaying the three-dimensional scan image and / or the identification result.

[0147] In some embodiments, the imaging method may also use the second detector assembly 600 according to the above-mentioned embodiment of the present invention to correct the scattered signal. It should be understood that any embodiment of the second detector assembly in this article can be applied to the imaging method. In the above-mentioned step S30, the imaging method reconstructs a three-dimensional scanning image of the region of interest of the inspected object based on the detection data of the first detector assembly 300 and the second detector assembly 600. Thereby, the signal-to-noise ratio of the first detector assembly can be improved and the imaging quality can be improved accordingly.

[0148] In some embodiments, before executing step S10, the imaging method may also preload or generate configuration information or correction information, such as background data, air data, etc.

[0149] In the imaging method according to some embodiments of the present invention, other implementations of the imaging system used are as described above and are accordingly incorporated into the embodiments of the imaging method, which will not be described in detail here.

[0150] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the present invention is not limited to the configuration and method of the above-described embodiments. On the contrary, the present invention is intended to cover various modifications and equivalent configurations. In addition, although the various elements and method steps of the disclosed invention are shown in various exemplary combinations and configurations, other combinations including more or less elements or methods also fall within the scope of the present invention.

Claims

1. An imaging system for radiographic inspection, comprising: an inspection area, wherein the inspected object can enter the inspection area, the inspection area includes an imaging area, a region of interest of the inspected object can enter the imaging area, the region of interest is a local region of the inspected object, the imaging area is a local region of the inspection area, and is configured to be sufficient to accommodate the region of interest of the inspected object; A first ray source assembly, for emitting X-rays, wherein the first ray source assembly comprises a plurality of distributed ray sources, each distributed ray source comprises a plurality of first target points, and all the first target points of the first ray source assembly are arranged in a first ray source plane; a first detector assembly for receiving X-rays emitted from the first ray source assembly and transmitted through the imaging area of ​​the imaging system, wherein the first detector assembly comprises a plurality of first detector units, each of which comprises a plurality of first detector crystals, The ray emission range of the first target point only covers the imaging area but does not cover the entire inspection area. The first radiation source assembly further includes at least one second target point, the radiation emission range of the second target point is selected to cover the inspection area, and The imaging system is configured to image the region of interest using the first target point, and to image the entire object under inspection using the second target point, so as to reconstruct a three-dimensional image of the region of interest.

2. The imaging system according to claim 1, further comprising a carrying device for carrying the inspected object, wherein: The imaging system is configured such that the first ray source assembly and the first detector assembly can move relative to the carrying device along the traveling direction of the inspected object, so that a region of interest of the inspected object can enter the imaging region.

3. The imaging system according to claim 2 further includes a ray source control device, which is configured to enable the first ray source assembly to simultaneously emit X-rays from at least two first target points to the imaging area at the same time when the region of interest is at least partially located in the imaging area, and among the at least two first target points from which the first ray source assembly simultaneously emits X-rays to the imaging area, the first detector crystals corresponding to the ray emission ranges of any two first target points do not overlap with each other.

4. The imaging system according to claim 3, wherein: The plurality of first detector units are arranged in a detector plane, and the detector plane is spaced apart from the first ray source plane by a predetermined distance along a traveling direction of the inspected object.

5. The imaging system according to any one of claims 1 to 4, wherein: The imaging area is located between the first ray source plane and an outer edge of the first detector assembly away from the first ray source assembly.

6. The imaging system according to claim 4, wherein: The detector plane and the first ray source plane are parallel to each other.

7. The imaging system according to any one of claims 1 to 4, wherein: Observed along the traveling direction of the inspected object, the multiple distributed radiation sources of the first radiation source assembly are configured to have a combined extension angle greater than 180 degrees around the imaging area.

8. The imaging system according to claim 7, wherein: The multiple distributed radiation sources of the first radiation source assembly are configured to extend completely around the imaging area to form a first radiation source ring.

9. The imaging system according to any one of claims 1 to 4, wherein: Each first target point of the first ray source assembly is arranged to be deflected by a first deflection angle along the traveling direction of the inspected object toward the first detector unit of the first detector assembly.

10. The imaging system of claim 9, wherein: The first deflection angle is between 1 degree and 5 degrees.

11. The imaging system according to any one of claims 2 to 4, wherein: Observing along the traveling direction, the first ray source assembly is configured to be rotatable within a predetermined range relative to the supporting device to adjust the position of the region of interest of the inspected object relative to the imaging region so that the region of interest of the inspected object is located within the imaging region.

12. The imaging system of claim 1, wherein: The imaging system also includes a ray source control device, which is configured to: when the first target point of the first ray source assembly emits X-rays, make the second target point not emit X-rays, and when the second target point of the first ray source assembly emits X-rays, make the first target point not emit X-rays.

13. The imaging system of claim 12, wherein: The ray source control device is configured to enable the first ray source assembly to simultaneously emit X-rays from at least two second target points to the inspection area at the same time. Among the at least two second target points that simultaneously emit X-rays to the inspection area by the first ray source assembly, the first detector crystals corresponding to the ray emission ranges of any two second target points do not overlap with each other.

14. The imaging system according to any one of claims 1 to 4, wherein: Observing along the traveling direction of the inspected object, the first detector assembly is arranged to be located radially inward of the first ray source assembly.

15. The imaging system of claim 14, wherein: The first detector assembly is configured to extend completely around the imaging region to form a detector ring.

16. The imaging system according to claim 14, further comprising a second detector assembly for receiving X-rays scattered from the object under inspection, wherein The second detector assembly includes a plurality of second detector units, each of which includes a plurality of second detector crystals.

17. The imaging system of claim 16, wherein: The plurality of second detector units of the second detector assembly are arranged correspondingly to the plurality of first detector units of the first detector assembly.

18. The imaging system of claim 17, wherein: The imaging system further includes a shielding member arranged so that the second detector unit does not receive direct X-rays emitted from the first ray source assembly.

19. The imaging system of claim 17, wherein: Along the traveling direction, the second detector crystals of each second detector unit are arranged to be spaced apart from the first detector crystals of the corresponding first detector unit so that the second detector unit does not receive direct X-rays emitted from the first ray source assembly.

20. The imaging system of claim 17, wherein: The number of second detector crystals in each second detector unit is equal to the number of first detector crystals in the corresponding first detector unit; or The number of second detector crystals in each second detector unit is smaller than the number of first detector crystals in the corresponding first detector unit.

21. The imaging system of claim 4, further comprising: a second ray source assembly, for emitting X-rays, wherein the second ray source assembly comprises a plurality of distributed ray sources, each distributed ray source comprises a plurality of third target points, all the third target points of the second ray source assembly are arranged in a second ray source plane, and the detector plane is spaced apart from the second ray source plane by a predetermined distance along the travel direction, The first detector assembly is further configured to receive X-rays emitted from the second ray source assembly and transmitted through the imaging area of ​​the imaging system. Wherein, the first ray source plane, the detector plane and the second ray source plane are sequentially distributed along the traveling direction, The ray source control device is configured to enable the second ray source assembly to simultaneously emit X-rays from at least two third target points to the imaging area at the same time when the region of interest is at least partially located in the imaging area. Among them, among the at least two third target points that simultaneously emit X-rays to the imaging area by the second ray source assembly, the ray emission range of each third target point can cover the imaging area, and the first detector crystals corresponding to the ray emission ranges of any two third target points do not overlap with each other.

22. The imaging system of claim 21, wherein: The imaging system is configured such that the first ray source assembly, the first detector assembly, and the second ray source assembly can move relative to the carrying device along the travel direction, so that the region of interest of the inspected object can enter the imaging region.

23. The imaging system of claim 21, wherein: The imaging area is located between the first ray source plane and the second ray source plane.

24. The imaging system of claim 21, wherein: The detector plane, the first ray source plane and the second ray source plane are parallel to each other.

25. The imaging system of claim 21, wherein: The ray source control device is configured to enable at least one first target point of the first ray source assembly and at least one third target point of the second ray source assembly to simultaneously emit X-rays to the imaging area at the same time when the region of interest of the inspected object is at least partially located in the imaging area, and Wherein, when at least one first target point of the first ray source assembly and at least one third target point of the second ray source assembly simultaneously emit X-rays to the imaging area, the detector crystals of the first detector assembly corresponding to the ray emission range of the first target point of the first ray source assembly and the detector crystals of the first detector assembly corresponding to the ray emission range of the third target point of the second ray source assembly do not overlap with each other.

26. The imaging system of any one of claims 1-4, wherein: The imaging system is further configured to reconstruct a three-dimensional scanned image of the region of interest of the inspected object based on the detection data of the first detector assembly.

27. An imaging method using the imaging system according to claim 2, comprising: (a) placing the object to be inspected on a carrying device of the imaging system; and (b) moving a first radiation source assembly and a first detector assembly of the imaging system relative to the carrying device along a travel direction so that a region of interest of the inspected object can enter an imaging region, and at the same time causing the first radiation source assembly to emit X-rays and causing the X-rays to pass through the imaging region and be received by the first detector assembly, The ray emission range of the first target point only covers the imaging area but does not cover the entire inspection area. The radiation emission range of the second target point is selected to cover the inspection area, and The imaging method uses the first target point to image the region of interest, and uses the second target point to image the entire object under inspection, so as to reconstruct a three-dimensional image of the region of interest.

28. The imaging method according to claim 27, wherein: The step of emitting X-rays by the first ray source assembly comprises: The first ray source assembly emits X-rays from at least two first target points to the imaging area at the same time, and among the at least two first target points from which the first ray source assembly emits X-rays to the imaging area at the same time, the first detector crystals corresponding to the ray emission ranges of any two first target points do not overlap, and X-rays are emitted from a second target point of the first ray source assembly.

29. The imaging method according to claim 27 or 28 further includes, after the inspected object is carried on the carrying device in step (a), adjusting the position of the region of interest of the inspected object relative to the imaging region by the carrying device so that the region of interest of the inspected object is located within the imaging region.

30. The imaging method according to claim 27 or 28 further includes, after the inspected object is carried on the carrying device in step (a), observing along the traveling direction, so that the first radiation source assembly is rotated within a predetermined range relative to the carrying device to adjust the position of the region of interest of the inspected object relative to the imaging region, so that the region of interest of the inspected object is located within the imaging region.

31. The imaging method according to claim 27 or 28, in, When the first target point of the first ray source assembly emits X-rays, the second target point is prevented from emitting X-rays, and when the second target point of the first ray source assembly emits X-rays, the first target point is prevented from emitting X-rays.

Images