Static CT (Computed Tomography) equipment and CT examination method

Abstract

The invention provides a static CT (Computed Tomography) device. The apparatus comprises one or more sets of inspection components, each set comprising: a multipoint distributed source configured to emit a beam of radiation; a detector facing the multi-point distributed source so as to receive a radiation beam emitted by the multi-point distributed source, the multi-point distributed source and the detector defining an inspection channel; and a grating disposed on the inspection channel between the multipoint distributed source and the detector. The grating has a periodic structure configured to diffract a radiation beam passing through the grating to form an interference pattern. The invention further provides a CT examination method.

Description

Technical Field

[0001] The present invention relates to the field of detection technology. Specifically, it relates to a static CT device. Background Art

[0002] Existing X-ray CT imaging devices are usually based on traditional X-ray absorption imaging. Its core components are an X-ray source and a detector, and an absorption image reflecting the attenuation characteristics of X-rays passing through a substance can be obtained. This absorption image has significant identification ability for substances with high density and strong X-ray absorption ability, and has significant imaging effects on substances such as metals and bones. Therefore, it has good utility in identifying prohibited items in the security inspection field and diagnosing bone diseases in the medical field. However, for substances composed of light elements (such as carbon, hydrogen, oxygen, nitrogen, etc.), the signals in the absorption image are weak, so there are great limitations. For example, it is difficult to observe prohibited items such as drugs blocked by metals in the security inspection field, and it is difficult to observe diseased tissues in the lungs in the medical field. Generally speaking, in order to improve the effects of security inspection and medical diagnosis, new technologies and new products that help improve the image identification ability of weakly absorbing substances should be explored. Summary of the Invention

[0003] According to one aspect of the present invention, there is provided a static CT device, including one or more groups of inspection components,

[0004] wherein each group of inspection components includes:

[0005] A multi-point distributed source, including an array arranged by a plurality of point sources, and configured to emit a radiation beam;

[0006] A detector facing the multi-point distributed source to receive the radiation beam emitted by the multi-point distributed source, the multi-point distributed source and the detector defining an inspection channel; and

[0007] A grating arranged between the multi-point distributed source and the detector;

[0008] wherein the grating has a periodic structure, and the periodic structure is configured to diffract the radiation beam passing through the periodic structure of the grating to form an interference pattern.

[0009] In one embodiment, the one or more groups of inspection components are respectively arranged in different sections in the extending direction of the inspection channel.

[0010] In one embodiment, the one or more groups of inspection components respectively emit radiation beams towards the inspection channel from different perspectives with respect to the circumference of the inspection channel in the transverse direction along the extending direction of the inspection channel for the object to be inspected.

[0011] In one embodiment, the one or more sets of inspection components include four sets of inspection components, and respective multi-point distributed sources of the four sets 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 towards the inspection channel from the top side, bottom side, left side, and right side of the inspection channel along a transverse cross-section in the extending direction of the inspection channel.

[0012] In one embodiment, the one or more sets of inspection components are arranged in the same section in the extending direction of the inspection channel, and each set of the one or more sets of inspection components is arranged with a multi-point distributed source and a detector relatively transversely in the extending direction of the inspection channel, and emits radiation beams towards the inspection channel from different perspectives in the circumferential direction of the inspection channel respectively.

[0013] In one embodiment, the one or more sets of inspection components are arranged such that directions in which respective multi-point distributed sources of each set of inspection components irradiate radiation beams towards the detector are staggered from each other.

[0014] In one embodiment, the one or more sets of inspection components include four sets of inspection components, and respective multi-point distributed sources of the four sets 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 towards the inspection channel transversely along the extending direction of the inspection channel from the top side, bottom side, left side, and right side of the inspection channel respectively.

[0015] In one embodiment, the one or more sets of inspection components are configured to operate simultaneously or in sequence.

[0016] In one embodiment, multiple sources of the multi-point distributed source of each set of the one or more sets of inspection components emit radiation beams in sequence.

[0017] In one embodiment, the grating of at least one set of the one or more sets of inspection components includes:

[0018] A first grating, which is adjacent to and parallel to the multi-point distributed source and is spaced from the multi-point distributed source by a first distance; and / or

[0019] A second grating, which is adjacent to and parallel to the multi-point distributed source and is spaced 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 adjacent to and parallel to the detector and is spaced from the multi-point distributed source by a third distance; and / or

[0020] A third grating, which is adjacent to and parallel to the detector and is spaced from the multi-point distributed source by a fourth distance, the fourth distance being not equal to the third distance.

[0021] In one embodiment, the grating of at least one set of inspection components in the one or more sets of inspection components includes 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.

[0022] One aspect of the present invention provides a method for performing a CT examination using the aforementioned static CT device, including:

[0023] Operating one or more sets of inspection components simultaneously or sequentially to perform an examination on the object to be inspected from different perspectives of the inspection channel,

[0024] wherein multiple point sources of the multi-point distributed source of each set of inspection components emit radiation beams in a flying spot manner so as to irradiate the object to be inspected from different angles.

[0025] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. Description of the Drawings

[0026] The drawings are used to better understand the solution and do not constitute a limitation to the present invention, wherein:

[0027] Figure 1 Various arrangements of the grating in the imaging device are shown.

[0028] Figure 2 The arrangement of one or more sets of inspection components according to an embodiment of the present invention is shown.

[0029] Figure 3 The arrangement of one or more sets of inspection components according to an embodiment of the present invention is shown, wherein one or more sets of inspection components are arranged in the same section.

[0030] Figure 4 The structure of one set of inspection components according to an embodiment of this aspect is shown, which includes three gratings G0, G1, and G2; an example of a grating is also shown.

[0031] Figure 5 The two-dimensional images of absorption T(a), phase Φ(b), and small-angle scattering D(c), and the 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 by the FBP algorithm after collecting 360 projections in one rotation (corresponding to formula (3) in the disclosure) are shown.

[0032] Figure 6The microscopic images of tissue sections after staining of human breast specimens 1-6 (a1-a6) are shown, as well as the corresponding sectional images of the linear attenuation coefficient μ after three-dimensional reconstruction in the XZ plane (b1-b6) and the sectional images of the refractive index decrement δ after three-dimensional reconstruction in the XZ plane (c1-c6). Detailed implementation mode

[0033] To more clearly elaborate the purpose, technical solution and advantages of the present invention, the embodiments of the present invention 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 invention, and should not be construed as a limitation of the present invention. In the specification and drawings, the same or similar reference numerals refer to the same or similar components or elements. For clarity, the drawings are not necessarily drawn to scale, and some well-known components and structures may be omitted in the drawings.

[0034] Unless otherwise defined, the technical terms or scientific terms used in the present invention should have the ordinary meaning understood by those of ordinary skill in the art to which the present invention pertains. The "first", "second" and similar terms used in the present invention do not denote any order, quantity or importance, but are only used to distinguish different components. The term "a" or "an" does not exclude a plurality. Words such as "comprising" or "including" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. "Connection" or "coupling" and similar terms are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "lower", "left", "right", "top" or "bottom", etc. are only used to indicate relative positional relationships, and when the absolute position of the object being described 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 there may be intermediate elements.

[0035] Figure 1 (a), (b), (c), (d) show various grating imaging arrangement modes, where G1, G2, G3 represent three gratings, which are respectively arranged Figure 1 as shown in (a), (b), (c), (d) between the source and the object to be inspected or between the object to be inspected and the detector.

[0036] In grating imaging technology, the wave nature and particle nature of X-rays can be utilized simultaneously, and three multi-characteristic information of absorption, phase and small-angle scattering can be obtained simultaneously. Among them, the absorption and phase information correspond to the imaginary part β and the real part δ of the complex refractive index n respectively:

[0037] n = 1 - δ + iβ (1)

[0038] where the linear attenuation coefficient μ has a linear relationship with the imaginary part β (λ is the wavelength of the X-ray):

[0039]

[0040] The three characteristic information of absorption T, phase Φ, and small-angle scattering D can be regarded as the integrals of the linear attenuation coefficient μ, refractive index decrement δ, and linear diffusion coefficient ζ respectively (where L is the propagation path of the X-ray, c Φ and c D are both constant values related to the imaging system):

[0041]

[0042] Considering that X-rays usually have an energy spectrum distribution, assuming the normalized energy spectrum distribution is S(E), then formula (3) can be written as:

[0043]

[0044] In Figure 1 (a), the function of grating G1 can be to form a self-imaging fringe image on the subsequent optical path. When X-rays interact with matter, this self-imaging fringe may undergo local distortion. This kind of distortion is at the micron and even sub-micron scale, and ordinary detectors cannot achieve such a high resolution. Therefore, grating G2 amplifies this signal, and by observing the strength change of the detector signal, the three multi-characteristic images of absorption, phase, and small-angle scattering can be extracted. When the X-ray source focus is small enough (such as synchrotron radiation or micro-focus X-ray machine), only grating G1 and grating G2 are needed, as shown in Figure 1 (a), (c).

[0045] When the X-ray source focus size is large (such as a conventional X-ray machine), the resulting blurring effect will lead to a poor imaging effect. Therefore, a grating G0 is added behind the X-ray source. Due to grating G0, the radiation beam emitted by the X-ray source is converted into a series of partially coherent micron-scale linear radiation beams, as shown in Figure 1 (b), (d).

[0046] The object to be inspected W can be placed between grating G0 and grating G1( Figure 1 (b)), or it can also be placed between grating G1 and grating G2( Figure 1 (c), (d)).

[0047] When the object to be inspected W is placed between grating G0 and G1, as shown in Figure 1As shown in (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, that is, the area of the grating G1 is large and the cost is high, and the X-rays passing through the object W need to be blocked by the gratings G1 and G2 before being received by the detector, so the utilization rate of X-rays is low.

[0048] When the object W is placed between the gratings G1 and G2, as Figure 1 shown in (c) and (d), in this configuration, the grating G1 is close to the light source, with a small area and low cost. The X-rays passing through the object W are only blocked by the grating G2, and the utilization rate of X-rays is higher. However, there are also disadvantages. The obtained phase and small-angle scattering signals are weakened, but this is not easy to cause detector signal saturation for some strongly scattering substances.

[0049] The absorption image (T above) reflects the attenuation characteristics of the substance to X-rays, corresponding to the imaginary part β of the complex refractive index of the substance in X-rays (complex refractive index n = 1 - δ + iβ); the phase image reflects the refraction effect of the substance to X-rays, corresponding to the real part δ of the complex refractive index of the substance in X-rays. Its beneficial effect is that for weakly absorbing substances, the contrast of the phase image is higher than that of the absorption image, and δ can be 2 to 3 orders of magnitude higher than β. Therefore, the weakly absorbing substances can be more clearly displayed through the phase image; the small-angle scattering image reflects the structural information of the mesoscopic size of the substance, and is very sensitive to the differences at the micron or sub-micron scale such as porosity and multi-fibers, and can break through the limitation of the resolution ability of absorption imaging. The phase and small-angle scattering images are good supplements to the absorption image, can effectively improve the overall imaging effect and resolution ability of the object W, and improve the adaptability and accuracy of the inspection process for different substances.

[0050] Figure 5 Shows the absorption T (a), phase Φ (b) and small-angle scattering D (c) two-dimensional images, and the 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 by the FBP algorithm after collecting 360 projections by rotating one week (corresponding to formula (3) in the specification). The absorption image reflecting the attenuation characteristics of the substance (corresponding to the linear attenuation coefficient μ); the phase image with higher contrast for weakly absorbing substances (corresponding to the refractive index decrement δ in the complex refractive index), reflecting the texture information of the internal and external structures of the object W; and the small-angle scattering image reflecting the structural information of the mesoscopic scale of the substance (corresponding to the linear diffusion coefficient ζ), reflecting the microscopic structures such as porosity and multi-fibers at the micron / sub-micron scale.

[0051] Figure 6Show the microscopic images of tissue sections (a1 - a6) after staining of human breast specimens 1 - 6, as well as the corresponding slice images (b1 - b6) of the linear attenuation coefficient μ after three - dimensional reconstruction in the XZ plane and the slice images (c1 - c6) of the refractive index decrement δ after three - dimensional reconstruction in the XZ plane.

[0052] In specimens 1, 2, 4, and 5, the arrows indicate tumor lesions (the darker - colored parts), in specimen 3, the arrow indicates pectoral muscle tissue, and in specimen 6, the arrow indicates the necrotic area (the darker - colored part).

[0053] Adipose tissue can be well - distinguished in all sample images. However, in the reconstructed images of phase information, the distinction between the tumor area and the surrounding fibroglandular tissue is better, and the necrotic area can also be distinguished. Grating imaging advantageously complements the identification deficiency of non - grating absorption two - dimensional imaging, enabling a more comprehensive analysis of the sample by combining the two.

[0054] As Figure 2 shown, according to an embodiment of the present disclosure, a static CT device includes one or more sets of inspection components. Each set of inspection components includes: a multi - point distributed source S, including an array arranged by a plurality of 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, and the multi - point distributed source S and the detector DT define 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, and the periodic structure is configured to diffract the radiation beam passing through the periodic structure of the grating to form an interference pattern. In an embodiment of the present disclosure, one or more sets of inspection components may include one set, two sets, three sets, four sets, or other numbers of inspection components, all of which can achieve static CT imaging. Each set of inspection components includes a multi - point distributed source S and a detector DT. The multi - point distributed source S includes a plurality of point sources, such as 5 point sources, 7 point sources, etc. These point sources are arranged in a row or a line, for example, arranged along a straight line, or can be arranged along a curve, or can be arranged in two rows or two lines or other forms. These point sources can emit radiation beams in sequence. The radiation beam can be a conical radiation beam, a fan - shaped beam, a pencil - shaped beam, etc. The shape of the radiation beam can be set according to needs, for example, setting a suitable collimator to shape the radiation emitted by each point source. That is to say, in the present disclosure, the multi - point distributed source S can include a suitable collimator. Figure 2It is shown 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 any one of gratings G0, G1, and G2, referring to any one of them and having the corresponding arranged positions shown in the figure; and, in some embodiments, one or more sets of inspection components may respectively include different gratings. For example, one set of inspection components includes grating G1, another set of inspection components includes grating G0, and still another set of inspection components includes grating G2, etc. Here, these different embodiment manners will not be elaborated. Those skilled in the art can set them as needed according to the teachings of this aspect.

[0055] In one embodiment, the static CT device includes only one set of inspection components. The inspection components include: a multi-point distributed source S, including an array arranged by a plurality of 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, the multi-point distributed source S and the detector DT defining an inspection channel; and a grating, arranged between the multi-point distributed source S and the detector DT. Due to the arrangement of the multi-point sources, multiple point sources can irradiate the object to be inspected from multiple angles, thereby achieving multi-angle imaging and synthesis of at least one tomogram of the object to be inspected without the object to be inspected moving, and constructing a three-dimensional image of the tomogram.

[0056] In one embodiment, multiple sets of inspection components are arranged in the extending direction of the inspection channel. For example, one or more sets of inspection components are respectively arranged in different sections of the inspection channel. These inspection components are arranged adjacent to each other or spaced apart from each other in different sections of the inspection channel. When the object to be inspected passes through the inspection channel, it passes through multiple sets of inspection components in sequence. In this embodiment, the viewing angles of each set of inspection components for irradiating the object to be inspected are different. For example, when the object to be inspected passes through the first set of inspection components, the multi-point distributed source S of the first set of inspection components irradiates the object to be inspected from the top side; when the object to be inspected continues to move along the inspection channel and passes through the second set of inspection components, the multi-point distributed source S of the second set of inspection components irradiates the object to be inspected from the bottom side; when the object to be inspected continues to move along the inspection channel and passes through the third set of inspection components, the multi-point distributed source S of the third set of inspection components irradiates the object to be inspected from, for example, the left side of the object to be inspected; when the object to be inspected passes through the fourth set of inspection components, the multi-point distributed source S of the fourth set of inspection components irradiates the object to be inspected from, for example, the right side of the object to be inspected. A fifth set of inspection components can be set as needed, and the multi-point distributed source S of the fifth set of inspection components irradiates the object to be inspected from the upper oblique side of the object to be inspected. Inspection components can be further set as needed. Those skilled in the art can set an appropriate number of inspection components according to the teachings of this aspect, combined 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 to be inspected, one or more sets of inspection components emit radiation beams from different viewing angles relative to the object to be inspected along the transverse direction of the extending direction of the inspection channel, that is, the circumferential direction of the inspection channel, towards the object to be inspected (in the inspection channel). According to this embodiment, since multiple sets of inspection components irradiate the object to be inspected from multiple viewing angles relative to the object to be inspected, multiple cross-sectional images of the object to be inspected can be obtained through computer processing; since the present invention provides a multi-point distributed source S, each set of inspection components can obtain images obtained by irradiating the object to be inspected from multiple viewing angles, so that a CT image of the object to be inspected can be obtained without, for example, rotating the object to be inspected or rotating the multi-point distributed source S-detector DT combination. In this embodiment, different from the CT imaging devices in the prior art, since a grating is provided, the CT imaging device with a grating can obtain more image information, such as obtaining three-dimensional image information related to the phase of the object to be inspected and multi-angle image information of small-angle scattering. These images can be obtained when the object to be inspected passes through the inspection channel once. By combining these image information, for biological samples in particular, more accurate information such as tissue recognition and structure judgment can be obtained, and the accuracy of the inspection is greatly improved compared with absorption images.

[0057] In one embodiment, the static CT device includes four sets of inspection components, Figure 2 showing the arrangement of the four sets of inspection components. Figure 2 In a), the multi-point distributed source S irradiates the object to be inspected from the top, Figure 2b) is that the multi-point distributed source S irradiates the object to be inspected from the left side of the object to be inspected, Figure 2 c) is that the multi-point distributed source S irradiates the object to be inspected from the bottom side, Figure 2 d) is that the multi-point distributed source S irradiates the object to be inspected from the right side.

[0058] In one embodiment, Figure 2 The four sets of inspection components shown in can be arranged in sequence on the inspection channel, for example, arranged along the extending direction of the inspection channel. The four sets of inspection components can be adjacent to each other or separated from each other at intervals.

[0059] The four sets of inspection components can irradiate the object to be inspected from four directions of up, down, left, and right. Through the sequential emission of the multi-point distributed source, it is possible to achieve the omnidirectional irradiation of the stationary object to be inspected, obtain more data, and obtain a three-dimensional image of the object to be inspected. In practical applications, three sets of inspection components can achieve, for example, the irradiation of a stationary object to be inspected in the up-down direction and one side direction, and the data obtained can fully construct a three-dimensional image of the object to be inspected.

[0060] In the above embodiment, it can be approximately considered that the multi-point distributed source S of each set of inspection components irradiates the corresponding detector DT along the transverse section of the inspection channel; here, 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 are actually surfaces. In this case, the so-called irradiation of the corresponding detector DT along the transverse section of the inspection channel actually means that the radiation beam is distributed in a space with a certain width, but the irradiation direction is generally along the transverse direction of the inspection channel. Those skilled in the art can arrange each set of inspection components according to the description of the present disclosure. For example, the four sets of inspection components irradiate the object to be inspected from the top side, bottom side, left side, and right side of the inspection channel respectively, and the irradiation directions of the four sets of inspection components are respectively generally in the direction from top to bottom, from bottom to top, from left to right, and from right to left, but the radiation beam of each set of inspection components is not a plane, but a conical surface. In another embodiment, the shape of the radiation beam is a fan shape. In this embodiment, the multi-point distributed source S can be configured with a corresponding generally linear detector DT.

[0061] In one embodiment, one or more sets of inspection components are arranged in the same section of the inspection channel. As Figure 3As shown, in this embodiment, since one or more sets of inspection components are arranged in the same section, it is necessary to avoid the multi-point distributed sources S of two sets of inspection components irradiating each other. In this embodiment, the respective multi-point distributed sources S of one or more sets of inspection components irradiate the object to be inspected from different perspectives relative to the object to be inspected, and one or more sets of inspection components are arranged such that the directions of the radiation beams irradiated by their respective multi-point distributed sources S form an angle with each other, or do not coincide. In other words, the multi-point distributed source S of each set of inspection components irradiates the corresponding detector DT to determine an irradiation surface (as described above, a general surface), and the corresponding multiple irradiation surfaces determined by one or more sets of inspection components do not coincide, but form an angle, so that the radiation beams irradiated towards each other do not interfere with each other. Figure 3 As shown in a) of Figure 3 , for example, two sets of inspection components arranged on the upper and lower sides, the detector DT of one set of inspection components and the multi-point distributed source S of the other inspection component are staggered from each other at the upper side position, and their corresponding multi-point distributed source S and detector DT are staggered from each other at the lower side position, and their irradiation directions cross so as to be staggered. The inspection components on the left and right sides are similarly staggered from each other so that the irradiation directions of the two sets of inspection components cross and are staggered. Figure 3 b) of Figure 3 shows another arrangement method, in which, for example, the detector DT of one set of inspection components and the multi-point distributed source S of the other inspection component are staggered from each other at the upper side position. Contrary to the form shown in a), other settings are similarly arranged in the opposite way, which will not be elaborated one by one. Those skilled in the art can think of other arrangement methods according to the arrangement method shown in this embodiment to meet different requirements.

[0062] In one embodiment, one or more sets of inspection components are configured to operate simultaneously. For example, in one embodiment, one or more sets of inspection components are arranged in a section. When the object to be inspected passes through this section, one or more sets of inspection components start to operate simultaneously, and their respective multi-point distributed sources S start to emit radiation beams to irradiate the object to be inspected. At the same time, their respective detectors DT receive the radiation signals passing through the object to be inspected and their respective gratings to implement the inspection. In this embodiment, the object to be inspected passes through one or more sets of inspection components once.

[0063] In one embodiment, one or more sets of inspection components are configured to operate in sequence. For example, in one embodiment, along the extending direction of the inspection channel, one or more sets of inspection components are respectively arranged in multiple sections of the inspection channel. When the object to be inspected moves through these sections, one or more sets of inspection components are configured to start to operate in sequence according to the forward movement of the object to be inspected.

[0064] In an embodiment of the present disclosure, for each set of inspection components, multiple point sources of the multi-point distributed source S generally emit radiation beams in sequence. Since the multiple point sources of the multi-point distributed source S are arranged in a straight line, the angles at which each point source irradiates the object to be inspected are actually different. Therefore, a set of inspection components can achieve multi-angle irradiation and obtain images of multiple tomograms of the object to be inspected.

[0065] In one embodiment, at least one set of inspection components of one or more sets of inspection components includes a grating G0, which is arranged adjacent to and parallel to the multi-point distributed source S and is spaced from the multi-point distributed source S by a first distance. Due to the presence of the grating G0, the radiation beams emitted by the multi-point distributed source S are modulated by the grating G0 into an interference pattern.

[0066] In one embodiment, at least one set of inspection components of one or more sets of inspection components includes a grating G0 and a grating G1. The grating G1 is arranged adjacent to and parallel to the multi-point distributed source S and is spaced from the multi-point distributed source S by a second distance, and the second distance is not equal to the first distance. That is to say, there are two gratings in at least one set of inspection components, namely the grating G0 and the grating G1. In one embodiment, the grating G1 is adjacent to the multi-point distributed source S; in another embodiment, the grating G1 is closer to the detector DT and is spaced from the detector DT by a third distance.

[0067] In one embodiment, at least one set of inspection components includes a grating G2, which is arranged adjacent to and parallel to the detector DT and is spaced from the multi-point distributed source DT by a fourth distance, and the fourth distance is not equal to the third distance. In one embodiment, at least one set of inspection components includes three gratings, namely the grating G0, the grating G1, and the grating G2. The arrangement of the gratings can refer to Figure 1 the multiple configuration methods shown. The gratings G0, G1, and G2 are parallel to each other.

[0068] Figure 4 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 invention as needed. In this embodiment, three gratings G0, G1, and G2 are arranged between the multi-point distributed source S and the detector DT. The three gratings G0, G1, and G2 are parallel to each other and parallel to the detector DT. In Figure 4 it, on the ray path of each radiation beam, the ratio of the distance L between the gratings G0 - G1 and the distance D between the gratings G1 - G2 is the same, L1 / D1 = L2 / D2 = L3 / D3 = L4 / D4.

[0069] Figure 4Also shown in the figure is an implementation of the grating, for example, in the form of an array of slits. In this embodiment, the periodic structure of the grating is a slit, the periodic direction of the periodic structure can be the arrangement direction of multiple slits, and the extending direction of a single sub-structure (such as a slit) of the periodic structure is perpendicular to the arrangement direction of multiple slits. According to the present disclosure, when the extending direction of a single slit forms a very small angle with the inspection channel (the extending direction of the inspection channel, such as Figure 4 the direction indicated by the movement arrow of the object to be inspected W in the figure, that is, the z direction), for example, when it is 10 -4 degrees, the interference fringes or Moiré fringes generated by the periodic structure formed by the arrangement of multiple slits will change greatly. Therefore, in the present disclosure, as long as the extending direction of a single slit is set to form a very small angle with the inspection channel, the requirements of the present invention can be met. In one embodiment, in Figure 4 the radiation beam irradiation direction is the Y direction, the extending direction of the inspection channel is the Z direction, and the moving direction of the object to be inspected W is the Z direction. For example, the extending direction of a single slit can be transverse to the extending 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 extending direction of the inspection channel and is horizontally arranged from left to right (Z direction) in Figure 4 . Here, it should be noted that the radiation beam irradiation direction Y only represents the general irradiation direction of the radiation beam. Since the radiation beam can be a conical radiation beam, the irradiation direction of the conical radiation beam is the Y direction, but not any ray is strictly in the Y direction. It only means that the direction of the conical radiation beam is irradiated along the Y direction. Those skilled in the art should understand the situation as shown in Figure 4 . The radiation beam of the point source on the left side of the multi-point distributed source S can be shaped to be irradiated obliquely to the right along the Y direction so that the angular spread covers the detector DT; the radiation beam of the point source on the right side of the multi-point distributed source S can be shaped to be irradiated obliquely to the left along the Y direction so that the angular spread covers the detector DT; other point sources are set similarly so that the angular spread of the emitted radiation beam satisfies that the radiation beam covers the detector DT.

[0070] According to one aspect of the present aspect, a method for performing a CT examination is provided. For example, a method for performing a CT examination can be implemented using the above-mentioned static CT device. In this embodiment, the method includes:

[0071] Using one or more groups of inspection components to operate simultaneously or sequentially to perform an examination on the object to be inspected from different perspectives of the inspection channel,

[0072] wherein 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 irradiate the object to be inspected from different angles.

[0073] In an embodiment of the present disclosure, the object to be inspected can move within the inspection channel, so that one or more groups of inspection components can irradiate the object to be inspected from different perspectives respectively, thereby obtaining absorption images, small-angle scattering images, and phase images of different tomograms of the object to be inspected. By combining these images of different tomograms and using a suitable algorithm by a computer or a processor, at least a partial three-dimensional image of the object to be inspected is output, and based on these three-dimensional images, the internal components, tissues, structures, etc. of the object to be inspected are analyzed to obtain a more comprehensive and accurate analysis result.

[0074] It should be understood that various forms of the processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in the present invention can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in the present invention can be achieved, and no limitation is imposed herein.

[0075] In the technical solution of the present disclosure, the processing of collection, storage, use, processing, transmission, provision, and disclosure of the user's personal information involved all comply with the provisions of relevant laws and regulations and do not violate public order and good customs.

[0076] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A static CT device, comprising one or more groups of inspection components, wherein each group of inspection components includes: A multi-point distributed source, including an array arranged by multiple point sources and configured to emit a radiation beam; A detector facing the multi-point distributed source to receive the radiation beam emitted by the multi-point distributed source, the multi-point distributed source and the detector defining an inspection channel; And A grating arranged between the multi-point distributed source and the detector; wherein the grating has a periodic structure, and the periodic structure is configured to diffract the radiation beam passing through the periodic structure of the grating 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 the extending direction of the inspection channel.

3. The static CT device according to claim 2, wherein the one or more groups of inspection components emit radiation beams towards the inspection channel from different perspectives circumferentially with respect to the object to be inspected respectively in the transverse direction along the extending 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 towards the inspection channel from the top side, bottom side, left side and right side respectively in the transverse cross-section along the extending direction of the inspection channel.

5. The static CT device according to claim 1, wherein the one or more groups of inspection components are arranged in the same section in the extending direction of the inspection channel, and for each group of the one or more groups of inspection components, the multi-point distributed source and the detector are arranged oppositely in the transverse direction along the extending direction of the inspection channel, and emit radiation beams towards the inspection channel from different perspectives circumferentially respectively.

6. The static CT device according to claim 5, wherein the one or more groups of inspection components are arranged such that the directions in which the respective multi-point distributed sources of each group of inspection components irradiate the detector with radiation beams are staggered from each other.

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 towards the inspection channel from the top side, bottom side, left side and right side respectively in the transverse direction along the extending direction of the inspection channel.

8. The static CT device according to claim 1, wherein the one or more groups of inspection components are configured to operate simultaneously or sequentially.

9. The static CT device according to claim 1, wherein the multiple sources of the multi-point distributed source of each group of the one or more groups of inspection components emit radiation beams sequentially.

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

11. The static CT device according to claim 9, wherein the grating of at least one set of inspection components in the one or more sets of inspection components comprises a first grating, a second grating and a third grating, and the first grating, the second grating and the third grating are parallel to each other.

12. A method for performing a CT examination using the static CT device according to claim 1, comprising: Using one or more sets of inspection components to operate simultaneously or sequentially to perform an examination on an object to be examined from different perspectives of the inspection channels, wherein multiple point sources of the multi-point distributed source of each set of inspection components emit radiation beams in a flying point manner so as to irradiate the object to be examined from different angles.

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