Static CT device and CT examination method

Abstract

A static CT device and a CT examination method. The device comprises one or more sets of examination assemblies, each set of examination assembly comprising: a multi-point distributed source (S) configured to emit radiation beams; a detector (DT) facing the multi-point distributed source to receive the radiation beams emitted by the multi-point distributed source, wherein the multi-point distributed source and the detector define an examination channel; and gratings (G0, G1, G2) arranged in the examination channel between the multi-point distributed source and the detector. The gratings have a periodic structure configured to diffract the radiation beams passing through the gratings to form an interference pattern.

Description

Static CT equipment and CT examination methods

[0001] This application claims priority to Chinese patent application No. 202311771056.2 filed on December 21, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present disclosure relates to the field of detection technology, and in particular to a static CT device. Background Art

[0003] Related X-ray CT imaging equipment is usually implemented based on traditional X-ray absorption imaging. Its core components are X-ray sources and detectors, which can obtain absorption images that reflect the attenuation characteristics of X-rays passing through matter. This absorption image has significant recognition capabilities for materials with high density and strong X-ray absorption capabilities, and has significant imaging effects on materials such as metals and bones. Therefore, it has good effectiveness in identifying contraband in the security field and diagnosing bone diseases in the medical field. However, for materials composed of light elements (carbon, hydrogen, oxygen, nitrogen, etc.), the signal in the absorption image is weak, and therefore has great limitations. For example, it is difficult to observe contraband such as drugs obscured by metal in the security field, and it is difficult to observe pathological lung tissue in the medical field. Overall, in order to improve the effectiveness of security inspections and medical diagnoses, new technologies and products that help improve the image recognition capabilities of weakly absorbing materials should be explored. Summary of the Invention

[0004] According to one aspect of the present disclosure, a static CT device is provided, comprising one or more inspection components,

[0005] Each set of inspection components includes:

[0006] a multi-point distributed source comprising an array of a plurality of point sources arranged and configured to emit a radiation beam;

[0007] a detector facing the multi-point distributed source so as to receive the radiation beams emitted by the multi-point distributed source, the multi-point distributed source and the detector defining an inspection channel; and

[0008] a grating arranged between the multi-point distributed source and the detector;

[0009] The grating has a periodic structure, and the periodic structure is configured to cause a radiation beam passing through the periodic structure of the grating to diffract to form an interference pattern.

[0010] In one embodiment, the one or more groups of inspection components are respectively arranged in different sections in the extension direction of the inspection channel.

[0011] In one embodiment, the one or more inspection components emit radiation beams toward the inspection channel from different viewing angles relative to the inspection object in a circumferential direction of the inspection channel in a transverse direction of the extension direction of the inspection channel.

[0012] In one embodiment, the one or more groups of inspection components include four groups of inspection components, and the respective multi-point distributed sources of the four groups of inspection components are respectively arranged on the top side, bottom side, left side and right side of the inspection channel, so as to emit radiation beams toward the inspection channel from the top side, bottom side, left side and right side of the inspection channel along the transverse cross-section of the extension direction of the inspection channel.

[0013] In one embodiment, the one or more groups of inspection components are arranged in the same section in the extension direction of the inspection channel, and each group of inspection components of the one or more groups of inspection components has multi-point distributed sources and detectors arranged relatively laterally along the extension direction of the inspection channel, and emits radiation beams toward the inspection channel from different viewing angles in the circumferential direction of the inspection channel.

[0014] In one embodiment, the one or more groups of inspection components are arranged such that directions in which the multi-point distributed sources of each group of inspection components irradiate radiation beams toward the detector are staggered.

[0015] In one embodiment, the one or more groups of inspection components include four groups of inspection components, and the respective multi-point distributed sources of the four groups of inspection components are respectively arranged on the top side, bottom side, left side and right side of the inspection channel, so as to emit radiation beams toward the inspection channel from the top side, bottom side, left side and right side of the inspection channel along the transverse direction of the extension direction of the inspection channel.

[0016] In one embodiment, the one or more inspection components are configured to operate simultaneously or in a time sequence.

[0017] In one embodiment, the plurality of sources of the multi-point distributed source of each of the one or more groups of inspection assemblies emit radiation beams in a time sequence.

[0018] In one embodiment, the grating of at least one inspection component of the one or more inspection components comprises:

[0019] a first grating, the first grating being arranged adjacent to and parallel to the multi-point distributed source and spaced a first distance from the multi-point distributed source; and / or

[0020] a second grating, wherein the second grating is arranged adjacent to and parallel to the multi-point distributed source and is spaced apart from the multi-point distributed source by a second distance, the second distance being different from the first distance; or the second grating is arranged adjacent to and parallel to the detector and is spaced apart from the multi-point distributed source by a third distance; and / or

[0021] A third grating is arranged adjacent to and parallel to the detector and is spaced apart from the multi-point distributed source by a fourth distance, wherein the fourth distance is not equal to the third distance.

[0022] In one embodiment, the gratings of at least one inspection component of the one or more inspection components include 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.

[0023] One aspect of the present disclosure provides a method for performing a CT examination using the aforementioned static CT device, comprising:

[0024] Use one or more inspection components to operate simultaneously or sequentially to inspect the object from different viewing angles of the inspection channel,

[0025] The multiple point sources of the multi-point distributed source of each group of inspection components emit radiation beams in a flying point manner so as to irradiate the inspection object from different angles.

[0026] 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

[0027] The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present disclosure, wherein:

[0028] FIG1 shows various arrangements of gratings in an imaging device.

[0029] FIG2 illustrates an arrangement of one or more inspection components according to an embodiment of the present disclosure.

[0030] FIG3 shows an arrangement of one or more inspection components according to an embodiment of the present disclosure, wherein the one or more inspection components are arranged in the same section.

[0031] FIG4 shows the structure of a set of inspection components according to an embodiment of the present invention, which includes three gratings G0 , G1 and G2 ; and also shows an example of a grating.

[0032] Figure 5 shows the two-dimensional images of absorption T(a), phase Φ(b) and small-angle scattering D(c), and 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) obtained by collecting 360 projections in one rotation and reconstructing them using the FBP algorithm (corresponding to formula (3) in the briefing book).

[0033] FIG6 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

[0034] 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.

[0035] 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.

[0036] Figures 1(a), (b), (c), and (d) show various grating imaging arrangements, where G1, G2, and G3 represent three gratings, which are arranged between the source and the object under test or between the object under test and the detector as shown in Figures 1(a), (b), (c), and (d), respectively.

[0037] 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)

[0038] The linear attenuation coefficient μ is linearly related to the imaginary part β (λ is the wavelength of the X-ray):

[0039] 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):

[0040] 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:

[0041] 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).

[0042] 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).

[0043] 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 ) ).

[0044] When the object W is placed between gratings G0 and G1, as shown in Figure 1(b), the phase and small-angle scattering signals obtained in this configuration are stronger, and the imaging contrast and sensitivity are higher. However, there are also disadvantages, namely, the large area and high cost of grating G1, 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, resulting in low X-ray utilization.

[0045] 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, which increases the X-ray utilization rate. However, it also has disadvantages. The obtained phase and small-angle scattering signals are weakened. However, for some strongly scattering materials, this is not likely to cause detector signal saturation.

[0046] The absorption image (T above) reflects the material's attenuation characteristics for X-rays and corresponds to the imaginary part of the material's complex refractive index, β (complex refractive index n = 1-δ + iβ). The phase image reflects the material's refractive effect on X-rays and corresponds 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 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 the absorption image, effectively improving the overall imaging quality and resolution of the object under test, W, and enhancing the adaptability and accuracy of the inspection process for different materials.

[0047] Figure 5 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) in the handout). 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 W; 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.

[0048] FIG6 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.

[0049] 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).

[0050] Fat tissue was well distinguished in all sample images, but phase-reconstructed images showed better differentiation between the tumor region and surrounding fibroglandular tissue, and were also able to distinguish necrotic areas. Grating imaging advantageously complements the lack of identification in non-grating absorption 2D imaging, enabling a combination of the two for a more comprehensive analysis of the sample.

[0051] As shown in Figure 2, according to an embodiment of the present disclosure, a static CT device includes one or more inspection components, each of which includes: a multi-point distributed source S, comprising an array of multiple point sources and configured to emit a radiation beam; a detector DT, facing the multi-point distributed source S to receive the radiation beam emitted by the multi-point distributed source S, with the multi-point distributed source S and the detector DT defining an inspection channel; and a grating disposed between the multi-point distributed source S and the detector DT. In this embodiment, the grating has a periodic structure configured to diffract the radiation beam passing through the periodic structure of the grating to form an interference pattern. In the embodiments of the present disclosure, the one or more inspection components may include one, two, three, four, or another number of inspection components, all of which can achieve static CT imaging. Each inspection assembly includes a multi-point distributed source S and a detector DT. The multi-point distributed source S includes multiple point sources, such as five or seven point sources. These point sources are arranged in a row or line, for example, along a straight line, along a curve, or in two rows or lines, or in other configurations. These point sources can emit radiation beams in a time sequence. The radiation beams can be cone-shaped, fan-shaped, pencil-shaped, or the like. The shape of the radiation beams can be configured as needed, for example, by providing a suitable collimator to shape the radiation emitted by each point source. In other words, in the present disclosure, the multi-point distributed source S can include a suitable collimator. FIG2 shows that each set of inspection components includes gratings G0, G1, and G2. However, it should be understood that in other embodiments, one or more sets of inspection components may include only one of gratings G0, G1, and G2, and herein, any one of them is referred to and arranged in the corresponding positions shown. Furthermore, in some embodiments, one or more sets of inspection components may include different gratings, for example, one set of inspection components includes grating G1, another set of inspection components includes grating G0, and another set of inspection components includes grating G2, etc. These different embodiments are not described in detail here, and those skilled in the art can configure them as needed based on the teachings of this invention.

[0052] In one embodiment, a static CT device includes only one inspection assembly. The inspection assembly comprises: a multi-point distributed source S, comprising an array of multiple point sources and configured to emit a radiation beam; a detector DT, facing the multi-point distributed source S to receive the radiation beam emitted by the multi-point distributed source S, with the multi-point distributed source S and the detector DT defining an inspection channel; and a grating disposed between the multi-point distributed source S and the detector DT. Due to the arrangement of the multiple point sources, the multiple point sources can illuminate the object from multiple angles, thereby enabling multi-angle imaging and synthesis of at least one slice of the object without moving the object, thereby constructing a three-dimensional image of the slice.

[0053] In one embodiment, multiple groups of inspection components are arranged along the extension of the inspection channel, for example, one or more groups of inspection components are arranged in different sections of the inspection channel. These inspection components are located adjacent to or spaced apart from each other in different sections of the inspection channel. As the object passes through the inspection channel, they sequentially pass through the multiple groups of inspection components. In this embodiment, each group of inspection components illuminates the object from a different perspective. For example, when the object passes through the first group of inspection components, the multi-point distributed sources S of the first group of inspection components illuminate the object from the top. As the object continues to move along the inspection channel, it passes through the second group of inspection components, and the multi-point distributed sources S of the second group of inspection components illuminate the object from the bottom. As the object continues to move along the inspection channel, it passes through the third group of inspection components, and the multi-point distributed sources S of the third group of inspection components illuminate the object from, for example, the left side of the object. When the object passes through the fourth group of inspection components, the multi-point distributed sources S of the fourth group of inspection components illuminate the object from, for example, the right side of the object. A fifth group of inspection components can be provided as needed, with the multi-point distributed sources S of the fifth group of inspection components illuminating the object from diagonally above. Further inspection components can be provided as needed. Those skilled in the art can set a suitable number of inspection components according to the teachings of this aspect, in combination with actual needs and cost considerations; and these inspection components can be arranged in sequence along the inspection channel, and the intervals between adjacent inspection components can be predetermined equal intervals, or randomly arranged. In order to obtain more information about the object under inspection, one or more groups of inspection components emit radiation beams toward the inspection channel (the object under inspection in it) from different perspectives relative to the object under inspection along the transverse direction of the extension direction of the inspection channel, that is, the circumference of the inspection channel. According to this embodiment, since multiple groups of inspection components illuminate the object under inspection from multiple perspectives relative to the object under inspection, multiple cross-sectional images of the object under inspection can be obtained through computer processing; since the present disclosure provides a multi-point distributed source S, each group of inspection components can obtain images obtained by irradiating the object under inspection from multiple perspectives, thereby obtaining a CT image of the object under inspection without, for example, rotating the object under inspection or rotating the multi-point distributed source S-detector DT combination. In this embodiment, unlike CT imaging devices in related technologies, the grating is provided, so the CT imaging device with the grating can obtain more image information, such as phase-related three-dimensional image information of the object under examination and multi-angle image information of small-angle scattering. These images can be obtained when the object under examination passes through a single inspection channel. By combining these image information, more accurate tissue identification, structure judgment and other information can be obtained, especially for biological samples, which greatly improves the accuracy of the inspection compared to absorption images.

[0054] In one embodiment, the static CT apparatus includes four inspection components, as shown in Figure 2 . In Figure 2 a), a multi-point distributed source S illuminates the object from the top, in Figure 2 b), a multi-point distributed source S illuminates the object from the left, in Figure 2 c), a multi-point distributed source S illuminates the object from the bottom, and in Figure 2 d), a multi-point distributed source S illuminates the object from the right.

[0055] In one embodiment, the four groups of inspection components shown in FIG. 2 may be sequentially arranged on the inspection channel, for example, along the extension direction of the inspection channel. The four groups of inspection components may be adjacent to each other or spaced apart from each other.

[0056] Four sets of inspection components can illuminate the object from four directions: top, bottom, left, and right. By sequentially emitting from multiple distributed sources, the stationary object can be illuminated from all angles, acquiring more data and producing a three-dimensional image of the object. In practical applications, three sets of inspection components can illuminate a stationary object from, for example, the top, bottom, and one side. The data obtained is sufficient to construct a three-dimensional image of the object.

[0057] In the above embodiment, each set of inspection components can be roughly considered as a multi-point distributed source S illuminating a corresponding detector DT along the transverse cross-section of the inspection channel. It should be noted that each source of the multi-point distributed source S can emit a conical radiation beam, while the detector DT and the corresponding grating can actually be a plane. In this case, the illumination of the corresponding detector DT along the transverse cross-section of the inspection channel actually means that the radiation beam is distributed within a space of a certain width, but the illumination direction is generally along the transverse direction of the inspection channel. Based on the description of this disclosure, those skilled in the art can arrange each set of inspection components. For example, four sets of inspection components can illuminate the inspection object from the top, bottom, left, and right sides of the inspection channel, respectively. The illumination directions of the four inspection components are generally from top to bottom, from bottom to top, from left to right, and from right to left, respectively. However, the radiation beam of each inspection component is not a plane, but a conical surface. In another embodiment, the radiation beam is fan-shaped. In this embodiment, the multi-point distributed source S can be configured with a corresponding generally linear detector DT.

[0058] In one embodiment, one or more inspection components are arranged in the same section of the inspection channel. As shown in FIG3 , in this embodiment, since one or more inspection components are arranged in the same section, it is necessary to prevent the multi-point distributed sources S of the two inspection components from mutually irradiating each other. In this embodiment, the multi-point distributed sources S of each of the one or more inspection components illuminate the object from different perspectives relative to the object, and the one or more inspection components are arranged so that the directions of the radiation beams emitted by the multi-point distributed sources S are at an angle to each other, or do not overlap. In other words, the multi-point distributed sources S of each inspection component illuminate the corresponding detector DT to define an illumination plane (as described above, a general plane). The corresponding multiple illumination planes determined by the one or more inspection components do not overlap, but are angled, so that the opposing radiation beams do not interfere with each other. FIG3 a) shows, for example, two inspection components arranged on the upper and lower sides. The detector DT of one inspection component and the multi-point distributed source S of the other inspection component are staggered at the upper side, while the corresponding multi-point distributed sources S and detector DT are staggered at the lower side, with the illumination directions of the two intersecting to ensure the staggered illumination. The inspection assemblies on the left and right sides are similarly staggered, so that the illumination directions of the two inspection assembly groups intersect and are staggered. Figure 3b) shows another arrangement, where, for example, the detector DT of one inspection assembly and the multi-point distributed source S of another inspection assembly are staggered at the top, the opposite of the arrangement shown in a). Other configurations are similarly reversed and will not be described in detail here. Based on the arrangement shown in this embodiment, those skilled in the art will be able to conceive of other arrangements to meet different needs.

[0059] In one embodiment, one or more inspection components are configured to operate simultaneously. For example, in one embodiment, one or more inspection components are arranged within a section. When an object passes through the section, one or more inspection components simultaneously begin operating. Each multi-point distributed source S begins emitting a radiation beam to illuminate the object, while each detector DT receives radiation signals that pass through the object and its respective grating, thereby performing an inspection. In this embodiment, the object passes through one or more inspection components at a time.

[0060] In one embodiment, one or more inspection components are configured to operate sequentially. For example, in one embodiment, one or more inspection components are arranged in multiple sections of the inspection channel along the extension direction of the inspection channel. When the object under inspection moves through these sections, one or more inspection components are configured to start operating sequentially according to the forward movement of the object under inspection.

[0061] In the embodiments of the present disclosure, for each set of inspection components, the multiple point sources of the multi-point distributed source S generally emit radiation beams in a timed sequence. Because the multiple point sources of the multi-point distributed source S are arranged along a straight line, each point source effectively illuminates the object at a different angle. Therefore, a single set of inspection components can achieve multi-angle illumination, acquiring images of multiple slices of the object.

[0062] In one embodiment, at least one inspection component of the one or more inspection components comprises a grating G0, which is arranged adjacent to and parallel to the multi-point distributed source S and spaced a first distance from the multi-point distributed source S. Due to the presence of the grating G0, the radiation beam emitted by the multi-point distributed source S is modulated by the grating G0 into an interference pattern.

[0063] In one embodiment, at least one of the one or more inspection components includes a grating G0 and a grating G1. Grating G1 is arranged adjacent to and parallel to the multi-point distributed source S and separated from the multi-point distributed source S by a second distance, which is different from the first distance. In other words, at least one inspection component includes two gratings, namely, grating G0 and grating G1. In one embodiment, grating G1 is adjacent to the multi-point distributed source S; in another embodiment, grating G1 is closer to the detector DT and separated from the detector DT by a third distance.

[0064] In one embodiment, at least one inspection assembly includes a grating G2, which is arranged adjacent to and parallel to the detector DT and spaced a fourth distance from the multi-point distributed source DT, where the fourth distance is not equal to the third distance. In one embodiment, at least one inspection assembly includes three gratings: grating G0, grating G1, and grating G2. The gratings can be arranged in the various configurations shown in FIG. 1. Gratings G0, G1, and G2 are parallel to each other.

[0065] FIG4 shows the arrangement of a set of inspection components relative to the object to be inspected according to an embodiment of the present disclosure. It should be understood that, according to this embodiment, those skilled in the art can arrange each set of inspection components of one or more sets of inspection components of the present disclosure as needed. In this embodiment, three gratings G0, G1, and G2 are set between the multi-point distributed source S and the detector DT. The three gratings G0, G1, and G2 are parallel to each other and to the detector DT. In FIG4 , on the ray path of each radiation beam, the ratio of the spacing L between the gratings G0 and G1 and the spacing D between the gratings G1 and G2 is the same, L1 / D1=L2 / D2=L3 / D3=L4 / D4.

[0066] FIG4 also shows a method for realizing a grating, such as an array of slits. In this embodiment, the periodic structure of the grating is a slit, and the periodic direction of the periodic structure can be the arrangement direction of the multiple slits, while the extension direction of a single substructure (such as a slit) of the periodic structure is perpendicular to the arrangement direction of the multiple slits. According to the present disclosure, when the extension direction of a single slit is at a very small angle (for example, relative to a situation parallel to the inspection channel) to the inspection channel (the extension direction of the inspection channel, such as the direction shown by the arrow of the object W moving in FIG4, that is, the z direction), for example 10 -4 When the angle of the periodic structure is changed, the interference fringes or moiré fringes produced by the periodic structure composed of the arrangement of multiple slits will change significantly. Therefore, in the present disclosure, as long as the extension direction of a single slit is set to a very small angle with the inspection channel, the requirements of the present disclosure can be met. In one embodiment, in FIG4 , the irradiation direction of the radiation beam is the Y direction, the extension direction of the inspection channel is the Z direction, and the movement direction of the object under inspection W is the Z direction. For example, the extension direction of a single slit can be transverse to the extension direction of the inspection channel (i.e., perpendicular to the inspection channel). At this time, the arrangement direction of the slits (i.e., the periodic direction of the periodic structure) is parallel to the extension direction of the inspection channel, and in FIG4 , they are arranged horizontally from left to right (Z direction). Here, it should be noted that the radiation beam irradiation direction Y only represents the general irradiation direction of the radiation beam, because the radiation beam can be a conical radiation beam, and the irradiation direction of the conical radiation beam is the Y direction, which does not mean that any ray therein is strictly in the Y direction, but only means that the direction of the conical radiation beam is irradiated along the Y direction. Those skilled in the art should understand that as shown in Figure 4, the radiation beam of the point source located on the left side of the multi-point distributed source S can be shaped to irradiate obliquely to the right along the Y direction, so that the angle covers the detector DT; the radiation beam of the point source located on the right side of the multi-point distributed source S can be shaped to irradiate obliquely to the left along the Y direction, so that the angle covers the detector DT; other point sources are set similarly, so that the angle of the emitted radiation beam satisfies the radiation beam covering the detector DT.

[0067] According to one aspect of the present invention, a method for performing a CT examination is provided, for example, a method for performing a CT examination using the above-mentioned static CT device. In this embodiment, the method includes:

[0068] Use one or more inspection components to operate simultaneously or sequentially to inspect the object from different viewing angles of the inspection channel,

[0069] The multiple point sources of the multi-point distributed source S of each group of inspection components emit radiation beams in a flying-spot manner so as to illuminate the object to be inspected from different angles.

[0070] In an embodiment of the present disclosure, the object under inspection can move within the inspection channel, so that one or more groups of inspection components can illuminate the object under inspection from different perspectives, thereby obtaining absorption images, small-angle scattering images and phase images of different layers of the object under inspection. These images of different layers are combined, and a computer or processor uses a suitable algorithm to output a three-dimensional image of at least a portion of the object under inspection. Based on these three-dimensional images, the internal composition, tissue, structure, etc. of the object under inspection are analyzed to obtain more comprehensive and accurate analysis results.

[0071] 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 provided by this disclosure can be achieved. This is not limited herein.

[0072] 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.

[0073] 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 static CT device, comprising one or more inspection components, Each set of inspection components includes: A multi-point distributed source, comprising an array of a plurality of point sources arranged and configured to emit a radiation beam; a detector facing the multi-point distributed source so as to receive the radiation beam emitted by the multi-point distributed source, the multi-point distributed source and the detector defining an inspection channel; as well as A grating arranged between the multi-point distributed source and the detector; The grating has a periodic structure, and the periodic structure is configured to cause a radiation beam passing through the periodic structure of the grating to diffract to form an interference pattern. 2 . The static CT device according to claim 1 , wherein the one or more groups of inspection components are respectively arranged in different sections in an extension direction of the inspection channel.

3. The static CT device according to claim 2, wherein the one or more inspection components emit radiation beams toward the inspection channel from different viewing angles relative to the object to be inspected in the circumferential direction of the inspection channel in a transverse direction of the extension direction of the inspection channel.

4. The static CT device according to claim 3, wherein the one or more groups of inspection components include four groups of inspection components, and the respective multi-point distributed sources of the four groups of inspection components are respectively arranged on the top side, bottom side, left side and right side of the inspection channel, so as to emit radiation beams toward the inspection channel from the top side, bottom side, left side and right side of the inspection channel along the transverse cross-section of the extension direction of the inspection channel.

5. The static CT device according to claim 1, wherein the one or more inspection components are arranged in the same section in the extension direction of the inspection channel, and each of the one or more inspection components relatively arranges multi-point distributed sources and detectors in the transverse direction of the extension direction of the inspection channel, and emits radiation beams toward the inspection channel from different viewing angles in the circumferential direction of the inspection channel. 6 . The static CT device according to claim 5 , wherein the one or more groups of inspection components are arranged so that directions in which the multi-point distributed sources of each group of inspection components irradiate radiation beams toward the detector are staggered.

7. The static CT device according to claim 5, wherein the one or more groups of inspection components include four groups of inspection components, and the respective multi-point distributed sources of the four groups of inspection components are respectively arranged on the top side, bottom side, left side and right side of the inspection channel, so as to emit radiation beams toward the inspection channel from the top side, bottom side, left side and right side of the inspection channel along the transverse direction of the extension direction of the inspection channel. 8 . The static CT apparatus according to claim 1 , wherein the one or more groups of inspection components are configured to operate simultaneously or in a time sequence.

9. The static CT apparatus according to claim 1, wherein the multiple sources of the multi-point distributed sources of each group of examination components of the one or more groups of examination components emit radiation beams in a time sequence.

10. The static CT device according to claim 1, wherein the grating of at least one group of inspection components of the one or more groups of inspection components comprises: a first grating, the first grating being arranged adjacent to and parallel to the multi-point distributed source and spaced a first distance from the multi-point distributed source; and / or A second grating, wherein the second grating is arranged adjacent to and parallel to the multi-point distributed source and is spaced apart from the multi-point distributed source by a second distance, the second distance being not equal to the first distance; or the second grating is arranged adjacent to and parallel to the detector and is spaced apart from the multi-point distributed source by a third distance; and / or A third grating is arranged adjacent to and parallel to the detector and is spaced apart from the multi-point distributed source by a fourth distance, wherein the fourth distance is not equal to the third distance.

11. The static CT device according to claim 9, wherein the gratings of at least one of the one or more inspection components include 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.

12. A method for performing CT examination using the static CT device according to claim 1, comprising: Using one or more inspection components to operate simultaneously or sequentially to inspect the object under inspection from different viewing angles of the inspection channel, The multiple point sources of the multi-point distributed sources of each group of inspection components emit radiation beams in a flying spot manner so as to irradiate the inspected object from different angles.

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