CN-121994837-A - Linear CT imaging system with multi-space direction imaging capability and scanning imaging method

Abstract

The application provides a linear CT imaging system with multi-space direction imaging capability and a scanning imaging method, and relates to the technical field of image processing and radiation imaging. The system comprises a conveying device, a plurality of imaging units and a plurality of scanning main fans, wherein the conveying device is used for enabling a scanning object to move along a preset linear scanning track, each imaging unit comprises at least one ray source and at least one detector, the imaging units comprise a first imaging unit and a second imaging unit, ray beams emitted by the ray sources of the first imaging unit form a first scanning main fan, ray beams emitted by the ray sources of the second imaging unit form a second scanning main fan, and the first scanning main fan and the second scanning main fan are located in different planes.

Inventors

• ZHANG LI
• CHEN ZHIQIANG
• Tian Zonghan
• CHANG MING
• LI LIANG

Assignees

• 同方威视技术股份有限公司
• 清华大学

Dates

Publication Date

20260508

Application Date

20260330

Claims (20)

1. 1. A linear CT imaging system having multi-spatial orientation imaging capabilities, the system comprising: a conveying device for moving the scanning object along a predetermined linear scanning trajectory; A plurality of imaging units, each of the imaging units comprising at least one radiation source for emitting a radiation beam and at least one detector for detecting the radiation beam emitted by the radiation source and passing through the scan object, Wherein the plurality of imaging units comprises a first imaging unit and a second imaging unit, the radiation source of the first imaging unit being positioned at a first spatial orientation with respect to the linear scan trajectory to scan the scan object from a first spatial direction, the radiation source of the second imaging unit being positioned at a second spatial orientation with respect to the linear scan trajectory to scan the scan object from a second spatial direction, the first spatial direction being different from the second spatial direction; The ray bundle emitted by the ray source of the first imaging unit forms a first scanning main sector, the ray bundle emitted by the ray source of the second imaging unit forms a second scanning main sector, and the first scanning main sector and the second scanning main sector are positioned in different planes.
2. 2. The system of claim 1, wherein the plane of the first main scan sector intersects the plane of the second main scan sector.
3. 3. The system of claim 2, wherein an angle between a plane in which the first main scan sector lies and a plane in which the second main scan sector lies is greater than 0 ° and less than 90 °.
4. 4. A system according to any one of claims 1-3, wherein the plurality of imaging units comprises at least two imaging units arranged independently of each other.
5. 5. A system according to any of claims 1-3, characterized in that at least part of the imaging units of the plurality of imaging units are formed by a spatial azimuthal movement transformation of the same imaging unit during scanning.
6. 6. The system of claim 4, wherein the first imaging unit comprises a first radiation source and the second imaging unit comprises a second radiation source, the first radiation source and the second radiation source being disposed independently of each other, the first radiation source and the second radiation source being spaced apart along a predetermined spatial trajectory.
7. 7. The system of claim 5, wherein the source of the first imaging unit and the source of the second imaging unit are formed by movement of the same source along a predetermined trajectory to a first spatial orientation relative to the linear scan trajectory and to a second spatial orientation relative to the linear scan trajectory, respectively.
8. 8. The system of claim 6 or 7, wherein the radiation sources of the plurality of imaging units are each located on a first side in a first direction relative to the conveyor, the detectors of the plurality of imaging units are located on a second side in the first direction relative to the conveyor, the first side and the second side being located on opposite sides of the conveyor in the first direction.
9. 9. The system of claim 6 or 7, wherein the radiation sources of at least two of the plurality of imaging units are each located on a first side in a first direction relative to the conveyor, the detectors of the plurality of imaging units are located on a second side in the first direction relative to the conveyor, the first side and the second side being located on opposite sides of the conveyor in the first direction; The radiation source of at least one of the plurality of imaging units is located on a third side in a second direction relative to the conveyor, the detector of at least one of the plurality of imaging units is located on a fourth side in the second direction relative to the conveyor, the third side and the fourth side being opposite sides of the conveyor in the second direction, the second direction being perpendicular to the first direction.
10. 10. The system of claim 8 or 9, wherein the linear scan trajectory comprises a first segment of linear scan trajectory, and wherein the first and second sources are configured to emit radiation beams to scan the scan object during movement of the scan object along the first segment of linear scan trajectory.
11. 11. The system of claim 10, wherein the linear scan trajectory comprises a first segment of linear scan trajectory and a second segment of linear scan trajectory, the first segment of linear scan trajectory and the second segment of linear scan trajectory being parallel to each other, the direction of motion of the scan object in the first segment of linear scan trajectory and the second segment of linear scan trajectory being opposite; The first imaging unit is configured such that the radiation source of the first imaging unit is positioned in a first spatial orientation to scan the scan object from a first spatial direction during movement of the scan object along the first segment of the linear scan trajectory, and the second imaging unit is configured such that the radiation source of the second imaging unit is positioned in a second spatial orientation to scan the scan object from a second spatial direction during movement of the scan object along the second segment of the linear scan trajectory.
12. 12. The system of claim 11, wherein the plurality of imaging units further comprises a third imaging unit and a fourth imaging unit, the radiation source of the third imaging unit being positioned at a third spatial orientation relative to the linear scan trajectory to scan the scan object from a third spatial orientation, the radiation source of the fourth imaging unit being positioned at a fourth spatial orientation relative to the linear scan trajectory to scan the scan object from a fourth spatial orientation, any two of the first, second, third, and fourth spatial orientations being different from each other.
13. 13. The system of claim 12, wherein the radiation beam from the radiation source of the third imaging unit forms a third main scan sector and the radiation beam from the radiation source of the fourth imaging unit forms a fourth main scan sector, any two of the first main scan sector, the second main scan sector, the third main scan sector, and the fourth main scan sector being in different planes.
14. 14. The system of claim 13, wherein the planes of any two of the first, second, third, and fourth main scanning sectors intersect each other.
15. 15. The system according to claim 13 or 14, characterized in that the projections of the first and third main scanning sectors on the plane of the detection plane of the detector are parallel to each other and/or, The projections of the second main scanning sector and the fourth main scanning sector on the plane of the detection plane of the detector are parallel to each other, and/or, The projections of the first scanning main sector and the second scanning main sector on the plane of the detection surface of the detector are perpendicular to each other, and/or, The projections of the third scanning main sector and the fourth scanning main sector on the plane of the detection surface of the detector are perpendicular to each other.
16. 16. The system of claim 15, wherein the linear scan trajectory comprises a first segment of linear scan trajectory and a second segment of linear scan trajectory, the first segment of linear scan trajectory and the second segment of linear scan trajectory being perpendicular to each other; The first imaging unit and the third imaging unit are configured such that during movement of the scan object along the first segment of the linear scan trajectory, the radiation source of the first imaging unit is positioned in a first spatial orientation to scan the scan object from the first spatial orientation, the radiation source of the third imaging unit is positioned in a third spatial orientation to scan the scan object from the third spatial orientation, and the second imaging unit and the fourth imaging unit are configured such that during movement of the scan object along the second segment of the linear scan trajectory, the radiation source of the second imaging unit is positioned in a second spatial orientation to scan the scan object from the second spatial orientation, and the radiation source of the fourth imaging unit is positioned in a fourth spatial orientation to scan the scan object from the fourth spatial orientation.
17. 17. The system of claim 15, wherein the linear scan trajectory comprises a first linear scan trajectory, a second linear scan trajectory, a third linear scan trajectory, and a fourth linear scan trajectory, the first and second linear scan trajectories being perpendicular to each other, the first and third linear scan trajectories being parallel to each other, a direction of motion of the scan object in the first and third linear scan trajectories being opposite, the second and fourth linear scan trajectories being parallel to each other, a direction of motion of the scan object in the second and fourth linear scan trajectories being opposite; The first imaging unit is configured such that during movement of the scan object along the first segment of the linear scan trajectory, the radiation source of the first imaging unit is positioned in a first spatial orientation to scan the scan object from a first spatial direction, the second imaging unit is configured such that during movement of the scan object along the second segment of the linear scan trajectory, the radiation source of the second imaging unit is positioned in a second spatial orientation to scan the scan object from a second spatial direction, the third imaging unit is configured such that during movement of the scan object along the third segment of the linear scan trajectory, the radiation source of the third imaging unit is positioned in a third spatial orientation to scan the scan object from a third spatial direction, and the fourth imaging unit is configured such that during movement of the scan object along the fourth segment of the linear scan trajectory, the radiation source of the fourth imaging unit is positioned in a fourth spatial orientation to scan the scan object from a fourth spatial direction.
18. 18. The system of claim 11, wherein the radiation sources of a first imaging unit and a second imaging unit of the plurality of imaging units are each located on a first side in a first direction relative to the conveyor, the detectors of the plurality of imaging units are located on a second side in the first direction relative to the conveyor, the first side and the second side being located on opposite sides of the conveyor in the first direction; The plurality of imaging units further comprises a third imaging unit, the radiation source of the third imaging unit being located on a third side in a second direction relative to the conveyor, the detector of at least one imaging unit of the plurality of imaging units being located on a fourth side in the second direction relative to the conveyor, the third side and the fourth side being opposite sides of the conveyor in the second direction, the second direction being perpendicular to the first direction; the third imaging unit scans the scan object from a spatial direction mainly in the second direction, and the first imaging unit and the second imaging unit scan the scan object from a spatial direction mainly in the first direction.
19. 19. The system of claim 18, wherein the radiation beam emitted by the radiation source of the third imaging unit forms a third main scan sector, any two of the first main scan sector, the second main scan sector, and the third main scan sector being in different planes.
20. 20. The system of claim 19, wherein the planes of any two of the first, second, and third main scanning sectors intersect each other.

Description

Linear CT imaging system with multi-space direction imaging capability and scanning imaging method Technical Field The present application relates to the field of radiation imaging and nondestructive testing techniques, and more particularly, to a linear CT imaging system and scanning imaging method with multi-spatial-direction imaging capability. Background CT imaging System scanning object CT imaging System in a straight line CT imaging system, projection data are acquired at different positions by making a scanning object or a radiation source and a detector perform relative straight line motion along a predetermined straight line direction, so as to realize tomographic imaging. Compared with a closed track scanning mode, the linear CT imaging system does not depend on rotation around an object, is more compact in overall structure and simpler in movement mode, and is more suitable for detection of continuously conveyed workpieces. However, the existing linear CT imaging systems still have shortcomings. The single-section linear CT imaging system scans along a single linear direction, so that the range of variation of the projection direction is limited, the angular space sampling is incomplete, and limited angular artifacts are easy to generate. To alleviate this problem, some solutions propose multi-segment linear CT scan imaging schemes that combine acquisition of projection data through multiple linear scan segments of different directions to expand the angular coverage. However, most of the existing multi-section linear CT imaging systems are still limited to the same imaging plane, essentially belong to coplanar multi-section scanning, and can only improve the problem of insufficient in-plane sampling, but lack sampling capability for the out-of-plane direction. It should be noted that the above information disclosed in this section is only for understanding the background of the inventive concept and thus, the above information may include information that does not constitute prior art. Disclosure of Invention In view of at least one of the above-mentioned technical problems, embodiments of the present application provide a linear CT imaging system and a scanning imaging method with multi-spatial direction imaging capability. According to a first aspect of the present application, there is provided a linear CT imaging system having multi-spatial imaging capabilities, the system comprising a conveyor for moving a scanning object along a predetermined linear scanning trajectory, a plurality of imaging units, each comprising at least one radiation source for emitting a radiation beam and at least one detector for detecting a radiation beam emitted by the radiation source and passing through the scanning object, wherein the plurality of imaging units comprises a first imaging unit and a second imaging unit, the radiation source of the first imaging unit being positioned in a first spatial orientation with respect to the linear scanning trajectory for scanning the scanning object from a first spatial orientation, the radiation source of the second imaging unit being positioned in a second spatial orientation with respect to the linear scanning trajectory for scanning the scanning object from a second spatial orientation, the first spatial orientation being different from the second spatial orientation, the radiation source of the second imaging unit emitting a radiation beam forming a first main scanning plane, the radiation source of the second imaging unit emitting a radiation beam forming a second main scanning plane, the second main scanning plane being different from the first main scanning plane. According to some embodiments of the application, the plane of the first main scanning sector and the plane of the second main scanning sector intersect. According to some embodiments of the application, an angle between a plane in which the first main scanning sector is located and a plane in which the second main scanning sector is located is greater than 0 ° and less than 90 °. According to some embodiments of the application, the plurality of imaging units includes at least two imaging units disposed independently of each other. According to some embodiments of the application, at least some of the plurality of imaging units are formed by a motion transformation of the spatial orientation of the same imaging unit during scanning. According to some embodiments of the application, the first imaging unit comprises a first radiation source and the second imaging unit comprises a second radiation source, the first radiation source and the second radiation source being arranged independently of each other, the first radiation source and the second radiation source being spaced apart along a predetermined spatial trajectory. According to some embodiments of the application, the radiation source of the first imaging unit and the radiation source of the second imaging unit are formed by a movement of the same