Radiation imaging device, ct imaging device, and imaging method

Abstract

The present disclosure provides a radiation imaging device. The device comprises: a radiation source, configured to emit radiation beams; a detector, configured to receive the radiation beams from the radiation source, wherein the radiation source and the detector define an examination channel; and at least one grating arranged in the examination channel between the radiation source and the detector. The at least one grating has a curved surface or is a groove-shaped surface having a plurality of angled planar sections, and the curved surface or the groove-shaped surface faces the radiation source.

Description

Radiation imaging device, CT imaging device, and imaging method

[0001] This application claims priority to Chinese patent application No. 202311773750.8 filed on December 21, 2023, the contents of which are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to the field of detection technology, specifically to a radiation imaging device, a CT imaging device, and an imaging method, and more particularly to a grating-based radiation imaging device, a CT imaging device, and an imaging method. Background Art

[0003] Related radiation imaging equipment is typically based on traditional X-ray absorption imaging. The core components of this equipment are an X-ray source and detector, which produce an absorption image reflecting the attenuation characteristics of X-rays passing through matter. This absorption image has significant recognition capabilities for high-density, highly X-ray-absorbing materials, and exhibits remarkable imaging effects on materials such as metal and bone. Therefore, it is highly effective in identifying contraband in security inspections and diagnosing bone diseases in medicine.

[0004] However, for weakly absorbing substances composed of light elements (carbon, hydrogen, oxygen, nitrogen, etc.), the corresponding attenuation level is low, resulting in a weak signal in the absorption image, and therefore has great limitations. For example, in the field of security inspection, it is difficult to observe contraband such as drugs that are blocked by metal, and in the medical field, it is difficult to observe diseased tissue in the lungs. On the other hand, the signal difference between different weakly absorbing substances is low and difficult to distinguish from each other. These problems may lead to misjudgment of the target object, such as missing drugs and contraband during security inspection, and unclear information about lung lesions during medical diagnosis. Overall, in order to improve the effectiveness of security inspection and medical diagnosis, new technologies and products that help improve the image recognition ability of weakly absorbing substances should be explored. Summary of the Invention

[0005] According to one aspect of the present disclosure, a radiation imaging device is provided, comprising: a radiation source configured to emit a radiation beam; a detector configured to receive the radiation beam from the radiation source, wherein the radiation source and the detector define an inspection channel; and at least one grating arranged on the inspection channel between the radiation source and the detector; the at least one grating is in the form of an arcuate surface, a grooved surface, or an L-shaped surface, and the detector is arranged in an arcuate, grooved, or L-shaped shape to extend parallel to the arcuate, grooved, or L-shaped surface of the at least one grating, wherein the arcuate, grooved, or L-shaped surface faces the radiation source to receive the radiation beam emitted by the radiation source.

[0006] In an embodiment, the at least one grating is configured to include a periodic substructure, causing rays passing through the periodic substructure to diffract to form an interference pattern.

[0007] In an embodiment, the at least one grating is a spherical grating.

[0008] In an embodiment, for the at least one grating having a structure of a grooved surface or an L-shaped surface, an extension direction of each substructure of the periodic substructure forms a non-zero angle with an extension direction of the inspection channel.

[0009] In an embodiment, an extension direction of each substructure of the periodic substructure is at right angles to an extension direction of the inspection channel.

[0010] In an embodiment, the detector and the at least one grating each have an integral structure.

[0011] In an embodiment, the detector and the at least one grating have a plurality of surface segments, wherein the plurality of surface segments constitute an arcuate surface, or the plurality of angled surface segments constitute a grooved surface or an L-shaped surface.

[0012] In an embodiment, the plurality of surface segments of the arcuate surface or the plurality of angled surface segments of the grooved surface or the L-shaped surface abut against each other or are spaced apart.

[0013] In an embodiment, the at least one grating includes: a first grating, which is arranged adjacent to and parallel to the radiation source and separated by a first distance; and / or a second grating, which is arranged adjacent to and parallel to the radiation source and separated by a second distance, and the second distance is not equal to the first distance; or, the second grating is arranged adjacent to and parallel to the detector and separated by a third distance; and / or a third grating, which is arranged adjacent to and parallel to the detector and separated by a fourth distance, and the fourth distance is not equal to the third distance.

[0014] In an embodiment, the radiation imaging device comprises a first grating, a second grating and a third grating, wherein the first grating, the second grating and the third grating are parallel to each other.

[0015] In an embodiment, the radiation imaging device is configured to generate at least one of an absorption image, a phase image, and a small-angle scattering image associated with at least a partial area of ​​the object on the inspection channel based on the signal detected by the detector.

[0016] In an embodiment, the radiation source is configured as a dual-energy radiation source.

[0017] According to another aspect of the present disclosure, a CT imaging device is provided, comprising: a slip ring configured to be rotatable; and a radiation imaging device according to the present disclosure, arranged on the slip ring so as to rotate along with the slip ring; wherein the radiation source, the detector, and the at least one grating are arranged on the slip ring, and the inspection channel passes through the slip ring.

[0018] According to another aspect of the present disclosure, a radiation imaging method is provided, which uses a radiation imaging device according to the present disclosure to irradiate a radiation beam on an object under inspection located in an inspection channel, and collects signals through a detector to generate at least one of an absorption image, a phase image, and a small-angle scattering image related to at least a partial area of ​​the object under inspection on the inspection channel based on the signals detected by the detector.

[0019] According to another aspect of the present disclosure, a CT imaging method is provided, which uses a CT imaging device according to the present disclosure to irradiate a radiation beam on an object under inspection located in an inspection channel, and collects signals through a detector to generate at least one of a three-dimensional absorption image, a phase image, and a small-angle scattering image associated with at least a partial area of ​​the object under inspection on the inspection channel based on the signals detected by the detector.

[0020] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present disclosure, wherein:

[0022] Figures 1(a) to 1(d) show various grating imaging arrangements.

[0023] 2 to 5 are schematic diagrams showing different embodiments of radiation imaging devices according to an embodiment of the present disclosure.

[0024] FIG6 shows a schematic diagram of a periodic substructure of a grating according to an embodiment of the present disclosure.

[0025] 7 to 10 are schematic diagrams showing different embodiments of radiation imaging devices according to embodiments of the present disclosure.

[0026] 11( a ) to 11 ( c ) are schematic diagrams illustrating different embodiments of a CT imaging device according to an embodiment of the present disclosure.

[0027] FIG12 shows a perspective schematic diagram of a radiation imaging device having a grating in a curved surface structure according to an embodiment of the present disclosure.

[0028] Figure 13 shows the two-dimensional images of absorption T (a), phase Φ (b), and small-angle scattering D (c), as well as the corresponding XY plane slice images of the three-dimensional images of the linear attenuation coefficient μ (d), refractive index decrement δ (e), and linear diffusion coefficient ζ (f) reconstructed using the FBP algorithm after collecting 360 projections during one rotation.

[0029] FIG14 shows microscopic images (a1-a6) of stained tissue sections of human breast specimens 1-6, as well as corresponding slice images (b1-b6) of the linear attenuation coefficient μ in the XZ plane after 3D reconstruction and slice images (c1-c6) of the refractive index decrement δ in the XZ plane after 3D reconstruction. DETAILED DESCRIPTION

[0030] To more clearly illustrate the objectives, technical solutions, and advantages of the present disclosure, embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the following description of the embodiments is intended to explain and illustrate the overall concept of the present disclosure and should not be construed as limiting the present disclosure. In the specification and drawings, the same or similar reference numerals refer to the same or similar parts or components. For the sake of clarity, the drawings are not necessarily drawn to scale, and some well-known parts and structures may be omitted in the drawings.

[0031] Unless otherwise defined, technical or scientific terms used in this disclosure should have the ordinary meaning understood by a person of ordinary skill in the art to which this disclosure belongs. The terms "first," "second," and similar terms used in this disclosure do not denote any order, quantity, or importance, but are simply used to distinguish different components. The terms "a" or "an" do not exclude a plurality. Terms such as "include" or "comprise" mean that the element or object preceding the term includes the elements or objects listed after the term and their equivalents, but do not exclude other elements or objects. Terms such as "connected" or "connected" are not limited to physical or mechanical connections but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," "right," "top," or "bottom" are used only to indicate relative positional relationships; if the absolute position of the described objects changes, the relative positional relationship may also change accordingly. When an element such as a layer, film, region, or substrate is referred to as being "on" or "under" another element, the element may be "directly" "on" or "under" the other element, or intervening elements may be present.

[0032] Figures 1(a), (b), (c), and (d) show various grating imaging arrangements, where G0, G1, and G2 represent three gratings, which are arranged between the source S and the object W or between the object W and the detector DT as shown in Figures 1(a), (b), (c), and (d), respectively.

[0033] In grating imaging technology, the wave and particle properties of X-rays can be simultaneously utilized to obtain three multi-characteristic information: absorption, phase, and small-angle scattering. The absorption and phase information correspond to the imaginary part β and real part δ of the complex refractive index n, respectively: n = 1-δ + iβ (1)

[0034] The linear attenuation coefficient μ is linearly related to the imaginary part β (λ is the wavelength of the X-ray):

[0035] The three characteristic information of absorption T, phase Φ and small-angle scattering D can be regarded as the integral of linear attenuation coefficient μ, refractive index decrement δ, and linear diffusion coefficient ζ respectively (where L is the propagation path of X-rays, c Φ and c D are all constant values ​​related to the imaging system):

[0036] Considering that X-rays usually have an energy spectrum distribution, assuming that the normalized energy spectrum distribution is S(E), formula (3) can be written as:

[0037] In Figure 1(a), grating G1 forms a self-imaging fringe pattern on its trailing optical path. When X-rays interact with matter, these self-imaging fringes may undergo local distortion. This distortion occurs on the micron or even submicron scale, a level beyond the resolution of conventional detectors. Therefore, grating G2 amplifies this signal and, by observing variations in the detector signal, extracts three multi-characteristic images: absorption, phase, and small-angle scattering. When the X-ray source's focal point is sufficiently small (e.g., synchrotron radiation or microfocus optical systems), only gratings G1 and G2 are required, as shown in Figures 1(a) and 1(c).

[0038] When the focal spot size of the X-ray source is large (such as a conventional X-ray machine), the blurring effect it brings will lead to poor imaging quality. Therefore, a grating G0 is added after the X-ray source. Due to the grating G0, the radiation beam emitted by the X-ray source is converted into a series of partially coherent micron-level linear radiation beams, as shown in Figure 1(b) and (d).

[0039] The object W can be placed between the grating G0 and the grating G1 ( FIG. 1( b ) ), or between the grating G1 and the grating G2 ( FIG. 1( c ) and ( d ) ).

[0040] When the object W is placed between gratings G0 and G1, as shown in Figure 1(b), the phase and small-angle scattering signals that can be obtained in this configuration are stronger, and the imaging contrast and sensitivity are higher. However, there are also disadvantages, namely that the grating G1 has a larger area and higher cost, and the X-rays after passing through the object W need to be blocked by gratings G1 and G2 before they can be received by the detector DT, resulting in low X-ray utilization.

[0041] When the object W is placed between gratings G1 and G2, as shown in Figures 1(c) and (d), in this configuration, grating G1 is close to the light source, has a small area and low cost, and the X-rays passing through the object W are only blocked by grating G2, resulting in higher X-ray utilization. However, this also has a disadvantage, namely, the obtained phase and small-angle scattering signals are weakened. However, for some strongly scattering materials, this is less likely to cause detector signal saturation.

[0042] The absorption image (T above) reflects the material's attenuation characteristics for X-rays, corresponding to the imaginary part of the material's complex refractive index, β (complex refractive index n = 1-δ + iβ). The phase image (Φ above) reflects the material's refractive effect on X-rays, corresponding to the real part of the material's complex refractive index, δ. This has the beneficial effect of providing higher contrast for weakly absorbing materials than the absorption image, with δ being 2 to 3 orders of magnitude higher than β. Therefore, weakly absorbing materials can be more clearly visualized using the phase image. The small-angle scattering image (D above) reflects the material's mesoscopic structural information and is highly sensitive to micron or submicron differences in porosity and fibrous structures, potentially overcoming the limitations of absorption imaging resolution. Phase and small-angle scattering images complement absorption images, effectively improving the overall imaging quality and resolution of the object under inspection, and enhancing the adaptability and accuracy of the inspection process for different materials.

[0043] The present disclosure aims to provide a radiation imaging device, a CT imaging device, and an imaging method. The radiation imaging device incorporates grating elements to obtain additional phase images and small-angle scattering images to supplement absorption images, thereby enhancing the imaging recognition capability of weakly absorbing materials. This helps improve the performance of the imaging system, further improving the detection rate of prohibited items in security inspection scenarios and further improving disease imaging diagnosis in medical settings.

[0044] 2 to 4 show schematic diagrams of different embodiments of a radiation imaging device 100 according to an embodiment of the present disclosure. As shown in FIG2 to 4, the radiation imaging device 100 may include a radiation source 10 and a detector 20. According to an embodiment of the present disclosure, the radiation source 10 is configured to emit a radiation beam or radiation ray. As an example, the radiation source 10 may be an X-ray source configured to emit X-rays. However, the embodiments of the present disclosure are not limited thereto. The radiation source 10 and the detector 20 may be opposite to each other in the Y direction so that the detector 20 can receive the radiation beam or radiation ray from the radiation source 10. The detector 20 may extend in the Z direction, thereby cooperating with the radiation source 10 to define an inspection channel 30 extending along the Z direction. When the radiation imaging device 100 is used to inspect an object, the object 50 to be inspected may be placed in the inspection channel 30, whereby the detector 20 may generate a detector signal based on the received radiation beam or radiation ray, thereby forming an inspection image related to at least a partial area of ​​the object 50 to be inspected.

[0045] According to an embodiment of the present disclosure, at least one grating is further arranged on the inspection channel 30 between the radiation source 10 and the detector 20. As an example, Figures 2 to 4 show that three gratings are arranged, namely a first grating 401, a second grating 402, and a third grating 403. Among them, the first grating 401 and the second grating 402 can be arranged adjacent to the radiation source 10, and are respectively at a first distance and a second distance from the radiation source 10. For example, the second distance can be greater than the first distance. The third grating 403 can be arranged adjacent to the detector 20. However, the embodiments of the present disclosure are not limited to this. The gratings can be arranged in a variety of ways as described above with reference to Figure 1. For example, only two gratings can be arranged between the radiation source 10 and the detector 20, as shown in Figures 1 (a) and (c). Alternatively, two gratings can be arranged between the object 50 and the detector 20, as shown in Figures 1 (a) and (b). That is, the second grating 402 and the third grating 403 are arranged adjacent to the detector 20, and may be at a third distance and a fourth distance from the detector 20, respectively. For example, the third distance may be greater than the fourth distance. It should be noted that the arrangement positions and the number of the gratings may be appropriately adjusted according to actual needs. In this document, for ease of understanding, the grating arrangement shown in Figures 2 to 4 will be described. However, it should be understood that the content described herein may be applied to other grating arrangements. In other embodiments of the present aspect, only the grating 401 may be arranged, or only the grating 402 may be arranged, or only the grating 403 may be arranged, or only the gratings 401 and 402, 401 and 403, or 402 and 403, etc. may be arranged. According to the present disclosure, any grating and combination of gratings may be provided in different embodiments.

[0046] In this article, a grating may refer to an optical device configured to include a periodic substructure, so that a radiation beam or radiation ray passing through the periodic substructure is diffracted to form an interference pattern. As an example, the "periodic substructure" of the grating can be understood as the lines of the grating, such as 400S shown in Figure 6. In one embodiment, the grating may be a slit structure, and light can pass through the slit diffraction to form interference fringes. In one embodiment, the grating may be a material that can modulate electromagnetic waves or radiation into interference fringes. As described above, by utilizing the interference pattern formed by the grating, the radiation imaging device 100 can obtain an absorption image of the object under test 50 while selectively obtaining a phase image and / or a small-angle scattering image, thereby improving the imaging performance index of the radiation imaging device 100 and improving the imaging recognition capability of the object under test 50. That is, the detector 20 in the radiation imaging device 100 according to the embodiment of the present disclosure can generate at least one of an absorption image, a phase image, and a small-angle scattering image associated with at least a portion of the area of ​​the object under test 50.

[0047] As shown in Figures 2 to 4, the grating can be arranged in various configurations. Accordingly, the shape of the detector 20 can be adjusted based on the grating configuration, enabling the detector 20 to cooperate with the grating to generate a suitable detector signal. Furthermore, the different shapes of the detector 20 can define inspection channels 30 having different configurations.

[0048] Specifically, the first grating 401, the second grating 402 and the third grating 403 can be arranged in the same structure as each other and parallel to each other. As an example, Figure 2 shows that the three gratings 401-403 are in an arc surface structure and are arranged parallel to each other with the same arc. Figure 3 shows that the three gratings 401-403 are in a groove surface structure. Figure 4 shows that the three gratings 401-403 are in an L-shaped surface structure. Further, the detector 20 can be arranged to extend parallel to the structure of the grating, thereby forming a corresponding shape. As an example, the detector 20 in Figure 2 is arranged to be in an arc shape parallel to the arc surface structure of the grating; the detector 20 in Figure 3 is arranged to be in a groove shape parallel to the groove surface structure of the grating; and the detector 20 in Figure 4 is arranged to be in an L-shaped shape parallel to the L-shaped surface structure of the grating. In this way, the first grating 401 , the second grating 402 , the third grating 403 and the detector 20 can be arranged parallel to each other, so as to cooperate with each other to generate detector signals for the radiation beams in corresponding areas.

[0049] As shown in Figures 2 to 4, the curved, grooved, or L-shaped surface structure of the grating and the curved, grooved, or L-shaped detector 20 are all arranged to face the radiation source 10 so as to receive the radiation beam emitted by the radiation source 10. Furthermore, in Figure 2, the curved detector forms an arc-shaped inspection channel. In Figure 3, the grooved detector forms a grooved inspection channel. In Figure 4, the L-shaped detector forms an L-shaped inspection channel.

[0050] In the embodiment of the arc-shaped inspection channel shown in FIG2 , due to the arc-shaped shape characteristics, the ray path of each ray emitted from the radiation source 10 can be made the same, so that the system performance is almost completely consistent, thereby ensuring that the imaging performance on different detector pixels is basically consistent, so that the imaging system structure is relatively simple and the imaging performance is good.

[0051] Furthermore, in the case of an arc-shaped inspection channel, since there is no problem of the radiation beam obliquely impinging on the grating and the detector, that is, the oblique angle is very small or negligible, the extension direction of the periodic substructure of the grating (e.g., the extension direction of the scribed lines) will not have a significant impact on the imaging effect, so there is no need for special requirements for the extension direction of the periodic substructure of the grating. For example, the grating scribed lines can be arranged parallel to the extension direction of the inspection channel 30 (i.e., the Z direction), or perpendicular to the extension direction of the inspection channel 30 (i.e., the Z direction). The extension direction of the periodic substructure of the grating (e.g., the extension direction of the scribed lines) can be at any angle to the extension direction of the inspection channel 30 (i.e., the Z direction).

[0052] As an example, as shown in Figure 2, the radiation source 10 can be arranged centrally relative to each grating and detector 20, and the curvature of the grating and the detector can be set so that the radiation source 10 is the same distance from each point on each grating and detector 20, thereby ensuring that each detector has consistent imaging performance, thereby optimizing image quality.

[0053] In one embodiment, the gratings 401-403 and the detector 20 in FIG. 2 can be formed as an integral structure. As an example, spherical gratings can be used to prepare the gratings 401-403 to achieve an integral curved surface structure. As an example, FIG. 12 shows a perspective schematic diagram of a radiation imaging device 100 having a curved surface structure of the grating according to an embodiment of the present disclosure.

[0054] In another embodiment, the gratings 401-403 and the detector 20 in FIG. 2 may be formed in a split structure. FIG. 5 shows a schematic diagram of another embodiment of a radiation imaging device 100 according to an embodiment of the present disclosure. As shown in FIG. 5 , a plurality of surface segments may be used to form the gratings 401-403 and the detector 20, respectively. In this document, a "surface segment" may refer to a sub-portion of a grating, such that all sub-portions together constitute the entire grating. For example, a plurality of surface segments may be arranged sequentially along the X direction to form a grating. For another example, each surface segment of a single grating may have the same size.

[0055] Let's take the third grating 403 as an example. The third grating 403 can have multiple surface segments D. These surface segments D can be arranged in the X direction to form an arcuate surface, thereby forming a third grating 403 with an arcuate surface structure. Similarly, the first grating 401, the second grating 402, and the detector 20 can each be composed of their own surface segments, and the sizes of the surface segments can vary as needed. In the case of a split structure, since there may be image gaps at the junctions between the surface segments, image interpolation processing is required during subsequent image processing.

[0056] As an example, multiple surface segments D may be arranged to abut against each other to form a nearly continuous arc surface structure, as shown in Figure 2. As another example, multiple surface segments D may be arranged to be spaced apart from each other, as shown in Figure 5.

[0057] In the embodiments shown in Figures 3 and 4, the slot-shaped and L-shaped inspection channels have rectangular shapes. In this disclosure, rectangular shape refers to those with right angles, not a completely rectangular shape. Therefore, a rectangular inspection channel can be achieved using a planar grating. Compared to curved channels, gratings in rectangular channels require no bending, have lower process requirements, and are less expensive, thus reducing the overall system size and making them more suitable for field applications.

[0058] As shown in Figures 3 and 4, the grating and detector can each include a first portion arranged along the X-direction and a second portion arranged along the Y-direction. The third grating 403 is used as an example for illustration. In the case of a grooved surface structure, the third grating 403 includes a first portion 4031 arranged along the X-direction, and two second portions 4032 and 4033 arranged along the Y-direction on either side of the first portion 4031. The first portion 4031 and the two second portions 4032 and 4033 together constitute the third grating 403. The second portions 4032 and 4033 are perpendicular to the first portion 4031, forming a grooved surface structure with rectangular features. In the case of an L-shaped surface structure, the third grating 403 includes a first portion 4031 arranged along the X-direction, and a second portion 4032 arranged along the Y-direction on either side of the first portion 4031. The first portion 4031 and the second portion 4032 constitute the third grating 403 and are perpendicular to each other, forming an L-shaped surface structure with rectangular features.

[0059] In the case of a rectangular channel, since the problem of grating oblique reflection is prone to occur, the extension direction of each substructure of the grating should not be parallel to the extension direction of the inspection channel 30 (i.e., the Z direction), since this will cause the influence of oblique reflection to be the largest. In other words, in the case of a grating with a grooved surface structure or an L-shaped surface structure, it is necessary to make the extension direction of each substructure form a non-zero angle with the extension direction of the inspection channel 30 (i.e., the Z direction) to reduce the influence of oblique reflection. Preferably, as shown in Figure 6, the extension direction of each substructure (e.g., the scribed line 400S) can be made at right angles to the extension direction of the inspection channel 30 (i.e., the Z direction); however, other angles are also possible and can achieve similarly good effects. That is, each scribed line 400S of the grating is extended in the Y direction perpendicular to the Z direction to minimize the influence of oblique reflection, thereby ensuring imaging performance.

[0060] While there are differences between the slot-shaped channel in Figure 3 and the L-shaped channel in Figure 4 , the primary difference lies in the grating and detector in Figure 4 each having a reduced portion compared to the embodiment in Figure 3 . For example, taking third grating 403 as an example, the embodiment in Figure 4 has a reduced portion 4033 compared to the embodiment in Figure 3 . With respect to other aspects such as grating arrangement and imaging principles, the embodiments in Figures 3 and 4 are essentially the same. Therefore, the L-shaped channel embodiment in Figure 4 will be used as an example for explanation below. It should be understood that the following description with reference to Figure 4 also applies to the slot-shaped embodiment in Figure 3 .

[0061] Furthermore, by making the grating and detector in FIG4 consist of only two parts, it is possible to reduce material usage and save economic costs. Furthermore, it should be noted that the placement of the radiation source 10 can be different depending on the specific shape of the slot shape and the L-shape, but this can be adjusted as needed based on actual effects, for example, as long as the desired imaging effect is achieved.

[0062] As shown in FIG4 , each of the first grating 401, the second grating 402, the third grating 403, and the detector 20 may include two portions. For example, the first grating 401 may include a first portion 4011 and a second portion 4012. The second grating 402 may include a first portion 4021 and a second portion 4022. The third grating 403 may include a first portion 4031 and a second portion 4032. The detector 20 may include a first portion 201 and a second portion 202. The respective first and second portions may be arranged at an angle to each other, for example, perpendicular to each other to form an L-shaped channel. Each portion is arranged parallel to each other between the first grating 401, the second grating 402, the third grating 403, and the detector 20.

[0063] In one embodiment, gratings 401-403 and detector 20 in FIG. 4 can be formed as an integrated structure. For example, each grating and detector 20 can be integrally formed. This simplifies the installation process of the gratings and detectors. Furthermore, due to the integrity of the integrated structure, angle loss during imaging can be avoided, thereby omitting the subsequent interpolation process. Similarly, as described above, gratings 401-403 and detector 20 in FIG. 3 can also be formed integrally.

[0064] In another embodiment, the two parts of each of the gratings 401-403 and detector 20 in Figure 4 can be formed separately rather than as a single piece. For example, the first part 4031 and the second part 4032 of the third grating 403 can be separately prepared and then arranged together to form the third grating 403. In this embodiment, each individual part of the grating and detector can be referred to as a "surface segment." Thus, each grating and detector can also be understood as having multiple (e.g., two) surface segments, which are arranged at angles to each other (e.g., at right angles) to form an L-shaped surface structure. This facilitates grating fabrication. For example, each grating part can be fabricated separately using a planar grating, and then simply arranged to form a grating device. Furthermore, the parameters of each grating part or detector part can be easily changed, increasing configuration flexibility. Since each part is prepared separately, the grating geometric parameters and the detector imaging parameters can be individually set based on the imaging characteristics of each part, thereby achieving optimal imaging performance in each part.

[0065] In addition, in this case, the respective corresponding parts of the grating and the detector can constitute separate imaging areas. As an example, as shown in Figure 7, the first grating 401, the second grating 402, the third grating 403 and the detector 20 can respectively include their respective second parts 4012, 4022, 4032 and 202. These second parts 4012, 4022, 4032 and 202 are arranged parallel to each other on the travel path of the radiation beam, thereby forming respective imaging areas. For example, forming the second imaging area in the radiation imaging device 100. Similarly, the radiation imaging device 100 can also include a first imaging area formed by the respective first parts 4011, 4021, 4031 and 201 of the grating and the detector. The setting parameters (e.g., geometric parameters and grating parameters) of the first imaging area and the second imaging area can be the same or different according to actual needs. For example, in the later image processing, the images obtained from the various imaging areas included in the radiation imaging device 100 can be fused to obtain the final inspection image of the object 50.

[0066] Furthermore, as shown in FIG8 , within each imaging region, for each radiation ray, the ratio of the spacings between adjacent gratings is the same across the plurality of gratings. For example, as shown in FIG8 , within the first imaging region formed by the first portion, the ratio (L1 / D1) of the spacing L1 between the first portion 4011 of the first grating 401 and the first portion 4012 of the second grating 402 to the spacing D1 between the first portion 4012 of the second grating 402 and the first portion 4031 of the third grating 403 under a ray R1 is equal to the ratio (L1' / D1') under any other ray R1'. Similarly, within the second imaging region formed by the second portion, the ratio (L2 / D2) of the spacing L2 between the second portion 4012 of the first grating 401 and the second portion 4022 of the second grating 402 and the second portion 4032 of the third grating 403 under a ray R2 is equal to the ratio (L2' / D2') under any other ray R2'. In this way, multiple grating segments can be arranged parallel to each other for each imaging region, achieving consistent effects on each ray. This allows for the construction of a separate, integrated imaging subsystem for each imaging region, enabling independent imaging operations. This ensures efficient imaging while simplifying grating fabrication and providing configuration flexibility. Specifically, parameters can be individually designed for each imaging subsystem, optimizing its performance.

[0067] In addition, in this case, since there may be imaging omissions at the connections between multiple parts or surface segments, image difference processing is required in the subsequent image processing.

[0068] As an example, the gratings 401-403 and the multiple surface segments or parts in each of the detectors 20 can be arranged to abut against each other. As another example, the gratings 401-403 and the multiple surface segments or parts in each of the detectors 20 can be arranged to be spaced apart from each other by a set distance. For example, as shown in Figure 7, the two surface segments or parts 201 and 202 of the detector 20 can be arranged to be spaced apart from each other by a certain distance. Alternatively, the two surface segments or parts 201 and 202 can also be arranged in a manner of abutting against each other. Thus, by arranging the gratings and the detectors in a split manner, the flexibility of the arrangement of the components can be further improved. In addition, sufficient adjustment space can be provided for the gratings, so that the relative position of the gratings (for example, the third grating) can be adjusted more easily according to the imaging effect to optimize the imaging quality.

[0069] As another example, as shown in FIG9 , the gratings 401-403 and the multiple surface segments or parts in each of the detectors 20 can be arranged to be staggered or overlapped. For example, the second part 202 of the detector 20 can be arranged on the side of the first part 201 in the X direction and overlap with the first part 201 in the Y direction. In one case, the first part 201 and the second part 202 can be staggered with each other while being spaced apart by a set distance. Alternatively, the first part 201 and the second part 202 can also be staggered with each other while abutting against each other. In this way, due to the staggered or overlapping arrangement, the problem of missing angles at the connection of multiple parts or surface segments can be avoided, thereby avoiding the subsequent interpolation processing to reduce the computational complexity.

[0070] Similarly, as shown in FIG10 , the embodiment of the slot-shaped channel can also be divided into multiple parts or surface segments to form each grating and detector in a separate manner. In addition, the embodiments of the slot-shaped channel can also apply the contents described above with reference to the embodiment of the L-shaped channel, such as the arrangement of the gratings and / or detectors.

[0071] In one embodiment, the radiation source 10 according to an embodiment of the present disclosure may be a single-energy radiation source, so that the radiation imaging device 100 performs single-energy imaging. In another embodiment, the radiation source 10 according to an embodiment of the present disclosure may be a dual-energy radiation source or a multi-energy radiation source, so that the radiation imaging device 100 performs dual-energy or multi-energy imaging. For example, two or more radiation sources (e.g., X-ray sources) emitting different energy spectra may be used as the radiation source 10 to achieve dual-energy or multi-energy imaging. For another example, the same radiation source may be configured to alternately emit two or more energy spectra to achieve dual-energy or multi-energy imaging.

[0072] Embodiments of the present disclosure also relate to a CT imaging device. The CT imaging device may include a slip ring configured to rotate, and a radiation imaging device 100 according to an embodiment of the present disclosure. The radiation imaging device 100 may be arranged on the slip ring to rotate with the slip ring.

[0073] Figures 11(a)-11(c) illustrate schematic diagrams of different embodiments of CT imaging devices according to embodiments of the present disclosure. Figure 11(a) illustrates a CT imaging device using the radiation imaging device 100 of the embodiment shown in Figure 2. Figure 11(b) illustrates a CT imaging device using the radiation imaging device 100 of the embodiment shown in Figure 5. Figure 11(c) illustrates a CT imaging device using the radiation imaging device 100 of another embodiment. In this radiation imaging device 100, each of the multiple gratings and detectors is constructed using fewer and larger surface segments. As shown in Figures 11(a)-11(c), the radiation imaging device 100 can be rotated in a direction P via a slip ring. As an example, the radiation source 10, the detector 20, the first grating 401, the second grating 402, and the third grating 403 can be arranged on the slip ring so that the inspection channel 30 passes through the slip ring.

[0074] An embodiment of the present disclosure also relates to a radiation imaging method, which uses a radiation imaging device 100 according to the present disclosure to irradiate a radiation beam to an object under inspection 50 located in an inspection channel 30, and collects signals through a detector 20 to generate at least one of an absorption image, a phase image, and a small-angle scattering image related to at least a partial area of ​​the object under inspection 50 on the inspection channel 30 based on the signal detected by the detector 20.

[0075] An embodiment of the present disclosure also relates to a CT imaging method, which uses a CT imaging device according to the present disclosure to irradiate a radiation beam to an object 50 located in an inspection channel 30, and collects signals through a detector 20 to generate at least one of a three-dimensional absorption image, a phase image, and a small-angle scattering image associated with at least a partial area of ​​the object 50 on the inspection channel 30 based on the signals detected by the detector 20.

[0076] Figure 13 shows two-dimensional images of absorption T (a), phase Φ (b), and small-angle scattering D (c), along with corresponding XY plane slice images of the linear attenuation coefficient μ (d), refractive index decrement δ (e), and linear diffusion coefficient ζ (f), reconstructed using the FBP algorithm after collecting 360 projections during one rotation (corresponding to formula (3) above). The absorption image (corresponding to the linear attenuation coefficient μ) reflects the attenuation characteristics of the material; the phase image (corresponding to the refractive index decrement δ in the complex refractive index) with higher contrast for weakly absorbing materials reflects the texture information of the internal and external structures of the object under test; and the small-angle scattering image (corresponding to the linear diffusion coefficient ζ) reflects the mesoscopic structural information of the material, reflecting microstructures such as porosity and multi-fibers at the micron / submicron scale.

[0077] FIG14 shows microscopic images (a1-a6) of stained tissue sections of human breast specimens 1-6, as well as corresponding slice images (b1-b6) of the linear attenuation coefficient μ in the XZ plane after 3D reconstruction and slice images (c1-c6) of the refractive index decrement δ in the XZ plane after 3D reconstruction.

[0078] The arrows in specimens 1, 2, 4, and 5 indicate tumor lesions (darkened areas), the arrow in specimen 3 indicates pectoral muscle tissue, and the arrow in specimen 6 indicates necrotic areas (darkened areas).

[0079] Fat tissue can be well distinguished in all sample images, but the tumor area and surrounding fibroglandular tissue can be better distinguished in the phase information reconstructed image, and the necrotic area can be distinguished.

[0080] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this disclosure can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved. This is not limited herein.

[0081] In the technical solutions disclosed herein, the collection, storage, use, processing, transmission, provision and disclosure of user personal information involved comply with the provisions of relevant laws and regulations and do not violate public order and good morals.

[0082] The above specific embodiments do not constitute a limitation on the scope of protection of this disclosure. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure shall be included within the scope of protection of this disclosure.

Claims

1. A radiation imaging device, comprising: a radiation source configured to emit a radiation beam; a detector configured to receive a radiation beam from the radiation source, the radiation source and the detector defining an inspection channel; as well as at least one grating disposed on the inspection channel between the radiation source and the detector; The at least one grating has a curved surface, a grooved surface, or an L-shaped surface structure, and the detector is arranged in a curved, grooved, or L-shaped shape to extend parallel to the curved surface, the grooved surface, or the L-shaped surface structure of the at least one grating, and the curved surface, the grooved surface, or the L-shaped surface faces the radiation source to receive the radiation beam emitted by the radiation source.

2. The radiation imaging device according to claim 1, wherein the at least one grating is configured to include a periodic substructure, causing rays passing through the periodic substructure to diffract to form an interference pattern.

3. The radiation imaging device according to claim 2, wherein the at least one grating is a spherical grating.

4. The radiation imaging device according to claim 2, wherein for the at least one grating having a structure in the form of a grooved surface or an L-shaped surface, an extension direction of each substructure of the periodic substructure forms a non-zero angle with an extension direction of the inspection channel. 5 . The radiation imaging device according to claim 4 , wherein an extension direction of each of the periodic substructures is at right angles to an extension direction of the inspection channel.

6. The radiation imaging device according to claim 1, wherein the detector and the at least one grating each have an integral structure.

7. The radiation imaging device according to claim 1, wherein the detector and the at least one grating have a plurality of surface segments, wherein the plurality of surface segments constitute an arc surface, or the plurality of angled surface segments constitute a grooved surface or an L-shaped surface. 8 . The radiation imaging device according to claim 7 , wherein the plurality of surface segments of the arc surface or the plurality of angled surface segments of the grooved surface or the L-shaped surface abut against each other or are spaced apart.

9. The radiation imaging device according to claim 1, wherein the at least one grating comprises: a first grating, the first grating being arranged adjacent to and parallel to the radiation source and spaced apart by a first distance; and / or a second grating, the second grating being arranged adjacent to and parallel to the radiation source and spaced apart by a second distance, the second distance being not equal to the first distance; or the second grating being arranged adjacent to and parallel to the detector and spaced apart by a third distance; and / or A third grating is disposed adjacent to and parallel to the detector and is spaced apart by a fourth distance, wherein the fourth distance is not equal to the third distance.

10. The radiation imaging device according to claim 9, comprising a first grating, a second grating and a third grating, wherein the first grating, the second grating and the third grating are parallel to each other.

11. The radiation imaging device according to claim 1, configured to generate at least one of an absorption image, a phase image and a small-angle scattering image related to at least a partial area of ​​the object under inspection on the inspection channel based on the signal detected by the detector.

12. The radiation imaging device according to claim 1, wherein the radiation source is configured as a dual-energy radiation source.

13. A CT imaging device, comprising: A slip ring configured to rotate; and The radiation imaging device according to any one of claims 1 to 12, arranged on the slip ring so as to rotate with the slip ring; The radiation source, the detector and the at least one grating are arranged on the slip ring, and the inspection channel passes through the slip ring.

14. A radiation imaging method, using a radiation imaging device according to any one of claims 1 to 12 to irradiate a radiation beam to an object under inspection located in an inspection channel, and collecting signals through a detector to generate at least one of an absorption image, a phase image, and a small-angle scattering image related to at least a partial area of ​​the object under inspection on the inspection channel based on the signals detected by the detector.

15. A CT imaging method, using the CT imaging device according to claim 13 to irradiate a radiation beam to an object under inspection located in an inspection channel, and collecting signals through a detector so as to generate at least one of a three-dimensional absorption image, a phase image, and a small-angle scattering image related to at least a partial area of ​​the object under inspection on the inspection channel based on the signals detected by the detector.

Images