Imaging system and method for radiographic inspection

Abstract

The present invention relates to an imaging system and method for radiographic inspection. An imaging system for radiographic inspection comprises: an inspection area, including an imaging area; a first ray source assembly, all first target points of which are arranged in a first ray source plane; a first detector assembly, a plurality of first detector units of which are arranged in a detector plane, the detector plane being spaced apart from the first ray source plane by a predetermined distance along a direction of travel of an inspected object; and a ray source control device, which is configured to cause the first ray source assembly to simultaneously emit X-rays from at least two first target points to the imaging area when an area of ​​interest of the inspected object is at least partially located in the imaging area, wherein, among the at least two first target points of the first ray source assembly that simultaneously emit X-rays to the imaging area, 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.

Description

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

[0002] The present 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 healthcare, security, and industry. CT scans generate three-dimensional images with high recognition capabilities. Existing CT scanning systems can be divided into dynamic spiral CT scanning systems and static CT scanning systems, depending on the motion of the radiation source relative to the object being examined during the scanning process.

[0004] In existing CT scanning systems, whether dynamic spiral or static, the X-ray emission range of the radiation source typically needs to cover the entire object being inspected, scanning and imaging the entire object. Furthermore, these CT scanning systems only emit X-rays from a single target point at a time. For example, existing static CT scanning systems may utilize a single distributed radiation source and a single detector system, or multiple distributed radiation sources and a shared detector system. However, each detector system can only receive X-rays from a single target point at a time. Therefore, the scanning speed of these CT scanning systems is limited by the rotation speed of the slip rings used in dynamic spiral scanning and the radiation emission frequency of the radiation source. In static CT scanning systems, the scanning speed is similarly limited by the radiation emission frequency of the radiation source. However, in some application scenarios, only the region of interest (ROI) of the object being inspected is of interest, and higher scanning speeds are required, such as for ROI imaging of living subjects. To increase the sampling frequency of the CT scanning system, additional detector systems are typically added, but this significantly increases 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] One object of the present invention is to provide an imaging system and method capable of scanning only a region of interest. Another object of the present invention is to provide an imaging system and method capable of increasing beam frequency. Another object of the present invention is to provide an imaging system and method capable of reducing equipment size and cost. Another object of the present invention is to provide an imaging system and method capable of better resolving problems within CT. Another object of the present invention is to provide an imaging system and method capable of reducing the impact 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 includes a plurality of distributed ray sources, each of which includes 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 includes a plurality of first detector units, each of which includes a plurality of first target points; A first detector unit includes a plurality of first detector crystals, and the plurality of first detector units are arranged in a detector plane, and the detector plane is separated from the first ray source plane 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 further 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 area so that the region of interest of the inspected object is located within the imaging area.

[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 large enough 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 present 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 configured to be deflected by a first deflection angle along a traveling direction toward a 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 direction of travel, 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 ray source assembly further includes at least one second target point, and the ray emission range of the second target point is selected to cover the inspection area, wherein the ray source control device is further configured to: 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.

[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 multiple 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 object under inspection, wherein the second detector assembly comprises a plurality of second detector units, and each second detector unit 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 shield 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 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 certain 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 a 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 distributed in sequence along the direction of travel, wherein the ray source control device is configured to cause 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, wherein, among the at least two third target points that the second ray source assembly simultaneously emits 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 targets 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 large enough 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 of the first ray source assembly and at least one third target 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 of the first ray source assembly and at least one third target 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 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 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 the 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 area, while causing the first ray source assembly to emit X-rays and causing the X-rays to pass through the imaging area 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 from at least two first target points to the imaging area at the same time, wherein, among the at least two first target points that the first ray source assembly simultaneously emits X-rays to the imaging area, 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.

[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 region of interest of the inspected object relative to the imaging area by the carrying device so that the region of interest of the inspected object is located within the imaging area.

[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, and rotating the first radiation source assembly 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 area, so that the region of interest of the inspected object 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 further includes: emitting X-rays from a second target point of the first ray source assembly, and the ray emission range of the second target point is 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 an imaging system can simultaneously emit X-rays from multiple targets, thereby increasing the radiation emission frequency of the imaging system, particularly without increasing the volume of the imaging system or the cost of additional detectors. By ensuring that the radiation emission range of the target of the radiation source assembly covers only the imaging area, the imaging system can perform transmission imaging only of the imaging area and the region of interest of the inspected object located therein, thereby reducing the volume and cost of the imaging system. By ensuring that the detector crystals corresponding to the simultaneously emitting targets do not overlap, signal acquisition can be performed simultaneously from multiple targets without interfering with each other, which can facilitate 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 schematic cross-sectional view 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] Figure 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] Figure 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] Figure 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 illustrate the principles of the present invention by way of example. The present invention is not limited to the preferred embodiments described, and the scope of the present invention is defined by the claims. The present invention will now be described in detail with reference to exemplary embodiments, some of which 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 fluoroscopic 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 schematic cross-sectional view 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, an imaging system for radiographic inspection includes an inspection region 100, a first radiation source assembly 200, and a first detector assembly 300. The first radiation source assembly 200 is configured to emit X-rays. The first detector assembly 300 is configured to receive X-rays emitted from the first radiation source assembly 200 and transmitted through the inspection region 100 of the imaging system. According to certain embodiments of the present invention, the first radiation source assembly 200 and the first detector assembly 300 are arranged to surround the inspection region 100, i.e., are located radially outside the inspection region 100. The imaging system is configured such that the first radiation source assembly 200 and the first detector assembly 300 can move relative to the object being inspected along a travel direction.

[0058] According to certain embodiments of the present invention, the imaging system defines an examination region 100. As used herein, the term "examination region" refers to an area accessible to an inspected subject. When an inspected subject is located within the examination region 100, X-rays emitted from the first ray source assembly 200 can penetrate the inspected subject and be received by the first detector assembly 300. In an exemplary embodiment, the examination region 100 includes a first end and a second end. In some embodiments, the inspected subject enters the examination region 100 from one of the first end and the second end and exits the examination region 100 from the other end.

[0059] According to certain embodiments of the present invention, the object under inspection includes a region of interest (ROI), which is a localized area of ​​the object under inspection. For example, when the object under inspection is a human body, the ROI may be a localized area of ​​the human body, such as the heart or lungs. According to certain 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 localized area of ​​the inspection region 100. Herein, "imaging region" refers to an area within which the ROI of the object under inspection can be placed and subjected to X-ray radiography. The imaging region 110 is sized to accommodate the ROI of the object under inspection. Herein, the central axis of the imaging region refers to an axis approximately at the center of a 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 radiation source assembly 200 and the first detector assembly 300 (and the second radiation source assembly 700 and the second detector assembly 600 described below).

[0060] In an exemplary embodiment, as Figure 1 As shown, the imaging system further includes a carrying device 400 for carrying the inspected object. According to certain embodiments of the present invention, the first ray source assembly 200 and the first detector assembly 300 are capable of moving relative to the carrying device 400 along a 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 certain embodiments of the present invention, the carrying device 400 can transport the inspected object back and forth 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 radiation 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, that is, 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” direction.

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

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

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

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

[0067] The above description describes 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, a broken line, or the like.

[0068] According to certain embodiments of the present invention, all first target points of the multiple distributed radiation sources 210 of the first radiation source assembly 200 are arranged in the same plane (hereinafter referred to as the "first radiation source plane"). That is, the multiple distributed radiation sources 210 of the first radiation source assembly 200 are arranged coplanarly. As used herein, "target points are located in the same plane" means that the beam exit points of the targets are all located in the same plane. In some embodiments, the first radiation source plane is substantially perpendicular to the direction of travel (or 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 when viewed along the direction of travel substantially reaches 360 degrees. 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] The above description describes the multiple distributed radiation sources 210 of the first radiation source assembly 200 as forming a complete radiation source ring. However, the present invention is not limited to this. In some embodiments, the radiation source ring formed by the multiple distributed radiation sources 210 of the first radiation source assembly 200 may be incomplete, i.e., may contain gaps. In some embodiments, the multiple distributed radiation sources 210 of the first radiation source assembly 200 are divided into multiple segments, and the distributed radiation sources 210 of different segments may be distributed at intervals around the imaging area 110. In an exemplary embodiment, as viewed along the direction of travel, the multiple distributed radiation sources 210 of the first radiation source assembly 200 have a combined extension angle greater than 180 degrees relative to the central axis around the imaging area 110. Herein, the extension angle of each distributed radiation source 210 relative to the central axis around the imaging area 110 represents the angular range of all first target points of the distributed radiation source 210 relative to the imaging area 110 (relative to the central axis of the imaging area 110). When the first radiation source assembly 200 includes multiple distributed radiation sources 210, the multiple distributed radiation sources 210 at different scanning positions relative to the imaging area 110 may provide a combined extension angle. Herein, a "combined extension angle" refers to an angle range resulting from combining the respective extension angles of the multiple distributed radiation sources 210 at different scanning positions relative to the imaging area 110. In some embodiments, the combined extension angles of the multiple distributed radiation sources 210 at different scanning positions relative to the imaging area 110 may be continuous or discontinuous.

[0071] The above description describes the multiple distributed radiation sources 210 of the first radiation source assembly 200 as forming a radiation source ring. However, the present invention is not limited thereto. In some embodiments, the multiple distributed radiation sources 210 of the first radiation source assembly 200 may extend continuously only partially around the imaging area 110, that is, the multiple distributed radiation sources 210 of the first radiation 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 multiple distributed radiation sources 210 of the first radiation source assembly 200 provide a continuous combined extension angle around the imaging area 110 relative to the central axis that 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 certain 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 can be configured based on factors such as the arrangement of the distributed radiation sources 210 in the first radiation source assembly 200 and / or the size of the inspected object. In some embodiments, the detector units in the first detector assembly 300 can also be arranged in a cost-effective manner, i.e., using as few detector units as possible to meet imaging requirements.

[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 so as not to block X-rays emitted by the distributed ray source 210 on the same side, while being able to receive X-rays emitted by the distributed ray source 210 on the other side.

[0075] In an exemplary embodiment, multiple first detector units 310 are arranged in the same plane (hereinafter referred to as the "detector plane"). As used herein, "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 multiple first detector units 310 are arranged in the same plane using 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 units 310 include a single row of detector crystals or multiple rows of detector crystals.

[0076] In some embodiments, as Figure 2As shown, along the central axis (or travel direction), the first ray source plane of the first ray source assembly 200 is spaced apart from the detector plane of the first detector assembly 300 by a predetermined distance. 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 area. 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] The above description describes multiple first detector units 310 forming a complete detector ring. However, the present invention is not limited thereto. In certain embodiments, the detector ring formed by multiple first detector units 310 may be incomplete, i.e., may contain gaps. In certain embodiments, the multiple first detector units 310 may be divided into multiple segments, and the first detector units 310 of different segments may be spaced apart and distributed around the imaging area.

[0079] Each first target point of the first radiation source assembly 200 has a radiation emission range. According to certain embodiments of the present invention, the radiation emission range of at least a portion of the first target points of the first radiation source assembly 200 is selected to cover the imaging region 110. Herein, "the radiation emission range of a target point covers the imaging region 110" means that the radiation emission range of the target point just covers the imaging region 110 or is slightly larger than the imaging region 110. The radiation emission ranges of these first target points of the first radiation source assembly 200 may or may not cover the examination region 100. In some embodiments, the radiation emission range of each of these first target points of the first radiation source assembly 200 is selected to be insufficient to cover the examination region 100, that is, the radiation emission range of each of these first target points is smaller than the examination region 100. In an exemplary embodiment, the radiation emission range of each first target point of the first radiation source assembly 200 can cover the imaging region 110, and optionally, the radiation emission range of each first target point is insufficient to cover the examination region 100. Compared with existing radiation sources whose radiation emission range covers the entire object under inspection, 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 object under inspection.

[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. In this case, the central axis of the imaging area 110 is the axis of rotation 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 such that every 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 that have passed 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 will be 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 radiation source assembly 200 is configured to be deflected along the direction of travel toward the first detector unit 310 of the first detector assembly 300 by a first deflection angle A1. In some embodiments, the first deflection angle is between 1° and 5°. In some embodiments, each distributed radiation source 210 is deflected around the axis of its first target point. In some embodiments, the first radiation source assembly 200 may further include a collimator for deflecting the direction of X-rays emitted by the distributed radiation sources 210 of the first radiation 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 radiation source 210 of the first radiation source assembly 200 are not blocked by the first detector assembly 300 before passing through the imaging area. In some embodiments, when the radiation emission direction of the first radiation source assembly 200 is deflected relative to the first detector assembly 300, the radiation 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 region 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 ray 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 further 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 position adjustment function may be used to move the region of interest of the inspected object to be completely located in the imaging area 110.

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

[0089] The ray emission control according to some embodiments of the present invention will be 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 radiation source control device (not shown). In some embodiments, the radiation source control device may be configured to control the radiation emission of the first radiation source assembly 200, such as the target emission sequence, emission frequency, emission current, etc.

[0091] According to certain embodiments of the present invention, the radiation source control device is configured to cause the multiple distributed radiation sources 210 of the first radiation source assembly 200 to simultaneously emit X-rays from at least two first target points toward the imaging area 110 at the same time when the region of interest of the inspected object is at least partially located within the imaging area 110. Consequently, two or more first target points within the first radiation source plane of the first radiation source assembly 200 simultaneously emit X-rays. Consequently, the imaging system according to embodiments of the present invention can increase the radiation emission frequency, particularly without increasing the volume occupied by the imaging system or the cost of additional detectors.

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

[0093] In some embodiments, among the at least two first target points that simultaneously emit X-rays to the imaging area 110 in 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 targets do not overlap with each other. By making the ray emission ranges of the first targets of the first ray source assembly 200 cover the imaging area 110, the imaging system can only perform transmission imaging of the imaging area 110 and the area 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 not overlap with each other, it is possible to perform non-interfering signal acquisition while multiple targets emit beams 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 simultaneously emit X-rays from six first target points 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 component 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 are respectively from different distributed ray sources 210. The first target points in each group do not overlap with each other (that is, each first target point belongs to only one group). In each group, the detector crystals of the first detector component 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 emit X-rays simultaneously at the same time, and makes the M groups of first target points emit X-rays in sequence.

[0096] In some embodiments, the first ray source component 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 number of first target points, and each group includes at least one first target point (that is, the number of first target points in each group can be one). The first target points in each group are respectively from different distributed ray sources 210. The first target points in each group do not overlap with each other (that is, each first target point belongs to only one group). In each group, the detector crystals of the first detector component 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 emit X-rays simultaneously at the same time, and makes the M groups of first target points emit X-rays in sequence.

[0097] In some embodiments, the first ray source component 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 are respectively from different distributed ray sources 210. The first target points in each group may partially overlap (that is, one first target point can belong to two or more groups at the same time). In each group, the detector crystals of the first detector component 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 emit X-rays simultaneously at the same time, and makes the M groups of first target points 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 component 200 that can emit X-rays simultaneously, the ray emission mode of the imaging system can be combined according to the number of groups of the first target points in the first ray source component 200, the group 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 be further configured to reconstruct a three-dimensional computed tomography (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 employ an iterative reconstruction algorithm, an analytical reconstruction algorithm, or a combination of different reconstruction algorithms when reconstructing the three-dimensional scan image of the region of interest of the inspected object.

[0100] When the radiation emission range of the first target point of the first radiation source assembly 200 only covers the region of interest (ROI), and the ROI is completely within the object under examination, the projection data may be truncated. In this case, imaging the ROI of the object under examination is considered an internal CT problem. Compared to image reconstruction where the radiation emission range covers the entire object under examination, the internal CT problem theoretically has a non-unique solution.

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

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

[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 the 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 pattern 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) according to any of the above radiation emission patterns, 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. Among the first target points in each group, 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 whole of the examined object, 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 the plurality of 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] To correct for scattered signals, according to certain 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 examination. According to certain embodiments of the present invention, the second detector assembly 600 is arranged to surround the examination region 100, i.e., located radially outside the examination region 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 certain 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 to correspond to the plurality of first detector units 310 of the first detector assembly 300, preferably in a one-to-one correspondence. According to certain embodiments of the present invention, the second detector units 610 are arranged to receive not direct X-rays emitted from the first radiation source assembly 200, but instead receive X-rays scattered by the object being examined.

[0110] In the exemplary embodiment, each second detector unit 610 includes a plurality of second detector crystals. The second detector crystals 611 of each second detector unit 610 are arranged side by side with the first detector crystals 311 of the corresponding first detector unit 310. As used herein, "side by side" means that the corresponding first and second detector crystals are at approximately the same radial and circumferential positions when viewed in the direction of travel. Along the direction of travel (or central axis), the corresponding second detector crystals 611 and the first detector crystals 311 are arranged to contact or be spaced apart from each other, as 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 spaced apart from the first detector crystals of the corresponding first detector unit 310, so that the second detector units 610 do not receive direct X-rays emitted from the first radiation source assembly 200. Thus, the second detector units 610 of the second detector assembly 600 are disposed outside the radiation emission range of the first target point of the first radiation 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 is a 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 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 direction of travel (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 arranged so that the second detector unit 610 does not receive direct X-rays emitted from the first ray source assembly 200. Because the second detector crystal is arranged in close proximity to the first detector crystal, some direct X-rays may be received by the second detector crystal. By providing the shielding member, the second detector unit 610 can be prevented from receiving direct X-rays, thereby improving the detection accuracy of the second detector assembly and improving 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 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 directly contact 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 a vertical direction when viewed along the circumferential direction.

[0116] Figure 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. Figure 10 FIG 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 9 and Figure 10As shown, the second detector crystal of the second detector unit 610 is arranged adjacent 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 further away from the second detector unit 610 and the second detector unit 310 (such as Figure 9 ), or closer to the second detector unit 610 and the second detector unit 310 (as shown Figure 10 shown). Figure 9 and Figure 10 In the illustrated embodiment, the shielding member 620 is a horizontal shielding member, that is, it extends substantially in the horizontal direction when viewed along the circumferential direction.

[0117] The above description describes the provision of a shield when the second detector crystal 611 of the second detector unit 610 contacts the corresponding first detector crystal 311 of the first detector unit 310 along the travel direction. However, the present invention is not limited to this. It should be understood that a shield may also be provided when the second detector crystal 611 of the second detector unit 610 is spaced apart from the corresponding first detector crystal 311 of the first detector unit 310.

[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 the shielding member may be arranged in any structure and form as long as it can prevent the second detector unit 610 from receiving direct X-rays.

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

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

[0121] In some embodiments, as Figure 6As shown, the number of second detector crystals 611 in each second detector unit is less than the number of first detector crystals 311 in 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 of the first detector unit 310. For example, based on the readings of each column of second detector crystals 611, the calculated values ​​of the scattered signals of each column of first detector crystals 311 in the area where the second detector crystals 611 are not provided can be obtained through interpolation or fitting, and scattered signal correction can be performed accordingly.

[0122] The above description describes 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. Figure 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. Figure 11 As shown, the imaging system further includes a second radiation source assembly 700 for emitting X-rays. When the imaging system includes the second radiation source assembly 700, the first detector assembly 300 is further configured to receive X-rays emitted from the second radiation source assembly 700 and transmitted through the examination region 100 (particularly, the imaging region 110) of the imaging system. According to certain embodiments of the present invention, when an object under examination is located in the examination region 100, the X-rays emitted from the second radiation source assembly 700 can penetrate the object under examination and be received by the first detector assembly 300.

[0123] According to certain embodiments of the present invention, the second radiation source assembly 700 includes a plurality of distributed radiation sources, each of which includes a plurality of third targets. Each distributed radiation source of the second radiation source assembly 700 can have the same structure, configuration, and arrangement as the distributed radiation source 210 of the first radiation source assembly 200 according to any of the above-described embodiments. The third targets of the second radiation source assembly 700 can have the same structure, configuration, and arrangement as the first targets of the first radiation source assembly 200 according to any of the above-described embodiments.

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

[0125] According to certain 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 coplanar. In some embodiments, the second radiation source plane is substantially perpendicular to the direction of travel (or central axis). In some embodiments, along the direction of travel (or central axis), the second radiation source plane of the second radiation source assembly 700 is separated 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 central axis). In an exemplary embodiment, for example, Figure 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 direction of travel (or central axis).

[0128] According to certain embodiments of the present invention, when the imaging system further includes a second radiation source assembly 700, the imaging region 110 is defined as being located between a first radiation source plane of the first radiation source assembly 200 and a second radiation source plane of the second radiation 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 being large enough to accommodate a region of interest of the object being examined.

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

[0130] According to certain 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 further 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 because the first radiation source assembly 200 and the second radiation source assembly 700 are respectively disposed on either side of the first detector assembly 300, the X-rays emitted by the first radiation source assembly 200 and the X-rays emitted by the second radiation 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 configured 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. Of the at least two third targets that simultaneously emit X-rays to the imaging area 110 from 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 certain 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 certain embodiments of the present invention, the X-ray source control device is configured to cause at least one first target of the first X-ray source assembly 200 and at least one third target of the second X-ray source assembly 700 to simultaneously emit X-rays toward the imaging area 110 at the same time when the region of interest of the inspected object is at least partially located within the imaging area 110. In this case, the first X-ray source assembly 200 and the second X-ray source assembly 700 of the imaging system can emit X-rays from at least two targets (at least one first target and at least one third target). Consequently, the imaging system can further improve the X-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 radiation source assembly 700. However, the present invention is not limited thereto. It should be understood that any embodiment described herein involving the first radiation source assembly 200 can be equally applied to the second radiation 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 using an imaging system including a first radiation source assembly 200 and a first detector assembly 300 as an example. However, it should be understood that the imaging system for implementing the imaging method according to the embodiments of the present invention may also include a second radiation source assembly 700.

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

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

[0141] During the process of X-ray emission by the first radiation source assembly 200, the multiple distributed radiation sources 210 of the first radiation source assembly 200 simultaneously emit X-rays from at least two first target points toward the imaging area 110. Of the at least two target points from which the first radiation source assembly 200 simultaneously emits X-rays toward the imaging area 110, the radiation 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 radiation emission ranges of any two target points do not overlap.

[0142] According to certain embodiments of the present invention, the imaging method may further adjust the position of the region of interest of the inspected object relative to the imaging area 110 through a 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 position adjustment function of the imaging system may be used to move the region of interest of the inspected object to be completely located in the imaging area 110.

[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 inspected object's region of interest relative to the imaging area 110 via 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 direction of travel by rotating the first radiation source assembly 200 relative to the imaging area 110 (or the carrying device 400) within a predetermined range to adjust the position of the inspected object's region of interest relative to the imaging area 110. Thus, the imaging method can adjust the inspected object's region of interest so that it is within the imaging area 110 through adjustment.

[0144] According to certain embodiments of the present invention, the imaging method may further provide a second target (large fan angle target) whose radiation emission range can cover the examination region 100 to address potential internal CT problems. It should be understood that any embodiment of the second target described herein may be applied to the imaging method.

[0145] In some embodiments, the step of emitting X-rays from the first radiation source assembly 200 in step S20 further includes emitting X-rays from a second target point of the first radiation source assembly 200. The radiation emission range of the second target point is selected to cover the examination area 100. In some embodiments, when the first target point of the first radiation source assembly 200 emits X-rays, the second target point is prevented from emitting X-rays, and when the second target point of the first radiation source assembly 200 emits X-rays, the first target point is prevented from emitting X-rays.

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

[0147] In some embodiments, the imaging method may also employ the second detector assembly 600 according to the aforementioned embodiment of the present invention to correct for scattered signals. It should be understood that any embodiment of the second detector assembly described herein may be applied to the imaging method. In step S30, the imaging method reconstructs a three-dimensional scanned image of the region of interest of the inspected object based on the detection data from the first detector assembly 300 and the second detector assembly 600. This improves the signal-to-noise ratio of the first detector assembly and, consequently, the imaging quality.

[0148] In some embodiments, before executing step S10 , the imaging method may also pre-load or generate configuration information or calibration 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, and are not described again 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 configurations and methods 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 fewer 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 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, the region of interest is a local region of the inspected object, and 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, configured to emit 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 includes a plurality of first detector units, each of which includes 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 being 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 area.

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 when the region of interest is at least partially located in the imaging area, and in which the first detector crystals corresponding to the ray emission ranges of any two first target points do not overlap with each other among the at least two first target points from which the first ray source assembly simultaneously emits X-rays to the imaging area.

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 a traveling direction of the inspected object toward the first detector unit of the first detector assembly.

10. The imaging system according to 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 area so that the region of interest of the inspected object is located within the imaging area.

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, enable the second target point to not emit X-rays, and when the second target point of the first ray source assembly emits X-rays, enable the first target point to 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 emit X-rays to the inspection area simultaneously with 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 corresponding 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 shield 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 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 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 distributed in sequence along the traveling direction, The ray source control device is configured to cause the second ray source assembly to emit X-rays from at least two third target points to the imaging area simultaneously 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 area.

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 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 toward 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 In which, 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 an 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 simultaneously causing the first radiation source assembly to emit X-rays and 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 to be inspected, 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 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, and X-rays are emitted from the 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 area by the carrying device so that the region of interest of the inspected object is located within the imaging area.

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, rotating the first ray source assembly 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 area, so that the region of interest of the inspected object is located within the imaging area.

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.

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