X-ray imaging device and control method thereof

Abstract

Provided are an X-ray imaging device and a control method thereof. The X-ray imaging device according to one embodiment of the present invention comprises: an X-ray generator comprising a plurality of X-ray sources that irradiate X-rays; an X-ray detector that detects the X-rays irradiated from the X-ray generator and transmitted through a subject to generate projection data; and a processor that generates a tomographic image on the basis of the projection data generated by the X-ray detector, wherein the processor: controls the X-ray generator to irradiate X-rays having different energies; and measures the thickness of the subject on the basis of the tomographic image generated using a plurality of pieces of projection data obtained from the X-rays irradiated at the different energies.

Description

X-ray imaging device and its control method

[0001] The present invention relates to an X-ray photographing device and an X-ray photographing image processing method, and more particularly, to an X-ray photographing device and an X-ray image processing method capable of measuring the type and thickness of a subject material.

[0002] When an X-ray imaging system captures a 2D X-ray image, the 2D X-ray image is an image in which X-rays are projected in one direction toward the X-ray imaging target. Therefore, when X-rays are projected toward the target in one direction, a problem occurs in which the image of the target overlaps and is obscured.

[0003] Meanwhile, to solve these problems, a representative device for irradiating patients with X-rays and taking pictures of an object is a computed tomography (CT) device. Among medical image processing devices, a computed tomography (CT) device, which is a tomography device, can provide cross-sectional images of an object, and has the advantage of being able to express the internal structure of an object (e.g., organs such as kidneys and lungs) without overlapping compared to a general X-ray device, so it is widely used for the precise diagnosis of diseases.

[0004] Recently, a tomosynthesis (DTS) X-ray imaging system that creates 3D images with low radiation compared to computed tomography (CT) devices has been introduced.

[0005] The tomosynthesis system is a technique that can obtain three-dimensional images with a low dose compared to computed tomography (CT), and can provide depth-specific tomographic images to eliminate overlapping or occlusion effects.

[0006] A tomosynthesis system typically rotates an analog X-ray generator in an arch shape around a rotational axis, and an X-ray detector moves or rotates according to the position of the X-ray generator while capturing multiple X-ray images, and then reconstructs the image into a three-dimensional image using a reconstruction algorithm.

[0007] Meanwhile, technology development for non-destructive testing of objects using X-ray photography is actively underway.

[0008] In the past, non-destructive testing was performed using a single X-ray generator, but testing using a single X-ray generator can extract internal structural information without destroying the test subject through the amount of X-ray absorbed.

[0009] However, since only the average value of the X-ray absorption characteristics of the material in the thickness direction can be confirmed through the resulting image, there is a problem in that the location of foreign substances in different planes cannot be identified.

[0010] In addition, when using a single X-ray generator as in the past, thickness measurement is possible if it is a single / same material, but there is a problem that an error may occur in the thickness measurement if a foreign substance is present.

[0011] The problem to be solved by the present invention is to provide an X-ray photographing device capable of determining the type and thickness of a material and a control method thereof.

[0012] Another object of the present invention is to provide an X-ray photographing device capable of non-destructive testing based on multi-energy X-rays and a control method thereof.

[0013] An X-ray photographing device according to an embodiment of the present invention includes an X-ray generator including a plurality of X-ray sources that irradiate X-rays, an X-ray detector that detects X-rays irradiated from the X-ray generator and transmitted through a subject to generate projection data, and a processor that generates a tomographic image based on the projection data generated through the X-ray detector, wherein the processor controls the X-ray generator to irradiate X-rays having different energies, and measures a thickness of the subject based on the tomographic image generated using a plurality of projection data generated through X-rays irradiated with different energies.

[0014] In an embodiment, the processor is characterized in that it controls the X-ray generator so that the plurality of X-ray sources irradiate X-rays having a first energy, and controls the X-ray detector so that the plurality of first projection data in which the X-rays having the first energy pass through the subject are acquired.

[0015] In an embodiment, the processor is characterized in that, after irradiating an X-ray having the first energy, the X-ray generator is controlled so that the plurality of X-ray sources irradiate an X-ray having a second energy different from the first energy, and the X-ray detector is controlled so that the plurality of second projection data obtained by X-rays having the second energy transmitted through the subject are acquired.

[0016] In an embodiment, the processor is characterized in that it controls the X-ray generator so that the plurality of X-ray sources sequentially irradiate X-rays having the first energy.

[0017] In an embodiment, the processor is characterized in that it controls the X-ray generator so that the plurality of X-ray sources sequentially irradiate X-rays having the second energy.

[0018] In an embodiment, the plurality of X-ray sources are characterized by including at least one first X-ray source configured to irradiate X-rays having a first energy and at least one second X-ray source configured to irradiate X-rays having a second energy different from the first energy.

[0019] In an embodiment, the first X-ray source and the second X-ray source are characterized in that they are arranged alternately.

[0020] In an embodiment, the processor is characterized in that it controls the X-ray generator to irradiate the second X-ray source after irradiating the first X-ray source.

[0021] In an embodiment, the processor is characterized in that it generates a first tomographic image captured through X-rays having the first energy based on the plurality of first projection data, and generates a second tomographic image captured through X-rays having the second energy based on the plurality of second projection data.

[0022] In an embodiment, the subject includes a plurality of materials, and the plurality of materials have different X-ray absorption rates depending on the energy of the X-rays, and the processor is characterized in that it measures the types and thicknesses of the plurality of materials included in the subject by using a plurality of tomographic images obtained by irradiating the subject with X-rays having different energies.

[0023] In an embodiment, the processor is characterized in that it calculates a difference in intensity between the first tomographic image and the second tomographic image based on a first tomographic image obtained by irradiating the subject with X-rays having a first energy and a second tomographic image obtained by irradiating the subject with X-rays having a second energy different from the first energy, and measures the types and thicknesses of a plurality of materials included in the subject based on the difference in intensity.

[0024] In an embodiment, the processor is characterized in that it performs clustering by material region based on a first tomographic image obtained by irradiating the subject with X-rays having a first energy and a second tomographic image obtained by irradiating the subject with X-rays having a second energy different from the first energy.

[0025] In an embodiment, the processor is characterized in that it calculates an X-ray attenuation coefficient for each material using a clustered image.

[0026] In an embodiment, the processor is characterized in that it generates a thickness map for measuring the thickness of a plurality of materials included in the subject using a clustered image.

[0027] According to the present invention, the accuracy of thickness measurement for each layer can be improved by distinguishing materials using multi-energy X-rays.

[0028] The present invention can non-destructively determine the type of material based on the fact that the absorption rate of X-rays varies depending on the material using multi-energy X-rays.

[0029] The present invention can provide a signal processing processor for improving the low signal-to-noise ratio (SNR) of multi-energy X-ray images.

[0030] Further scope of the applicability of the present invention will become apparent from the detailed description below. However, since various modifications and variations within the spirit and scope of the present invention will become apparent to those skilled in the art, it should be understood that the detailed description and specific examples, such as preferred embodiments of the present invention, are given by way of example only.

[0031] Figure 1 is a drawing for explaining an X-ray photographing device according to a conventional tomosynthesis system.

[0032] FIG. 2, FIG. 3 and FIG. 4 are conceptual diagrams for explaining an X-ray imaging device according to one embodiment of the present invention.

[0033] Figure 5 is a drawing illustrating a case where a conventional X-ray generator exists.

[0034] Figures 6 and 7 are conceptual diagrams for explaining a method of taking a tomographic image using multi-energy X-rays of the present invention.

[0035] FIGS. 8, 9, 10, 11, 12, and 13 are conceptual diagrams illustrating a method for generating a tomographic image and determining the thickness and type of a material using multi-energy X-rays according to an embodiment of the present invention.

[0036] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Regardless of the drawing numbers, identical or similar components will be given the same reference numbers and redundant descriptions thereof will be omitted. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably only for the convenience of writing the specification, and do not in themselves have distinct meanings or roles. In addition, when describing the embodiments disclosed in this specification, if it is determined that a specific description of a related known technology may obscure the gist of the embodiments disclosed in this specification, a detailed description thereof will be omitted. In addition, the attached drawings are only intended to facilitate easy understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and technical scope of the present invention.

[0037] Terms that include ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by these terms. These terms are used solely to distinguish one component from another.

[0038] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0039] Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0040] In this application, terms such as “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but should be understood not to exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0041] Figure 1 is a drawing for explaining an X-ray photographing device according to a conventional tomosynthesis system.

[0042] In a conventional tomosynthesis system (10), an X-ray generator (101) rotates about 20 to 50 degrees around a predetermined rotation axis while irradiating an X-ray to a photographing target (102). An X-ray detector (103) can generate an electrical signal corresponding to the dose of the X-ray transmitted.

[0043] Meanwhile, when the X-ray generator (101) rotates and irradiates the photographing target (102) with X-rays, the projected X-rays are detected by the X-ray detector (103), and a plurality of projection data (106, 107, 108) can be generated.

[0044] Meanwhile, based on the first plane (Plane 1) and the second plane (Plane 2) of the photographing target (102), each of the first point (104) and the second point (105) can be projected by the X-ray emitted by the X-ray generator (101) and mapped to each of the plurality of projection data (106, 107, 108).

[0045] In this case, the first point (104) and the second point (105) mapped to each of the plurality of projection data (106, 107, 108) may be mapped differently due to the change in the angle of incidence caused by the rotational movement of the X-ray generator (101). Therefore, an additional step of reconstructing a 2D or 3D X-ray tomographic image of the photographing target (102) based on the plurality of projection data (106, 107, 108) is required.

[0046] FIG. 2, FIG. 3 and FIG. 4 are conceptual diagrams for explaining an X-ray imaging device according to one embodiment of the present invention.

[0047] Referring to FIG. 2, the X-ray photographing device of the present invention, the X-ray photographing device (20) includes an X-ray generator (210) in which a plurality of X-ray sources (211, 212, 213, 214, 215) are arranged. The plurality of X-ray sources (211, 212, 213, 214, 215) are turned on or off to emit X-rays and irradiate X-rays to an object to be photographed (220).

[0048] The X-ray detector (230) can generate an electrical signal corresponding to the dose of X-rays transmitted. The X-ray source can also emit X-rays in an electric field manner.

[0049] Meanwhile, the X-ray photographing device (20) may have a horizontal movement method rather than the rotational movement of the conventional tomosynthesis system (10). For example, the X-ray photographing device (20) may be controlled to emit X-rays in the order of the first X-ray source (212), the second X-ray source (213), and the third X-ray source (214).

[0050] Meanwhile, based on the first plane (Plane 1) and the second plane (Plane 2) of the shooting target (220), each of the first point (240) and the second point (250) can be mapped to each of a plurality of projection data (260, 270, 280) and shot.

[0051] In this case, the first point (240) and the second point (250) can be mapped to each of the plurality of projection data (260, 270, 280) due to horizontal movement through turning on or off each of the plurality of X-ray sources (211, 212, 213, 214, 215) of the X-ray generator (210).

[0052] Therefore, an additional step is required to reconstruct a 2D or 3D X-ray tomographic image of the photographed object (220) based on multiple X-ray images (260, 270, 280).

[0053] In this case, unlike the conventional tomosynthesis system (10) of Fig. 1, a tomographic image must be generated by reconstructing multiple projection data by reflecting the characteristics of the X-ray sources operating horizontally on or off.

[0054] An X-ray photographing device (20) can take X-ray photographs of an object to be photographed in a horizontal movement manner in a first direction (u) by controlling the on or off of each of a plurality of X-ray sources included in an X-ray generator (210).

[0055] The X-ray generator (210) operates at least one X-ray source for a predetermined period of time (e.g., several msec to several hundred msec) while maintaining a gap between the X-ray sources that are turned on so that the X-ray distributions irradiated onto the X-ray detector (230) do not overlap. Meanwhile, the X-ray generator (210) can individually turn the X-ray sources on or off one by one when the X-ray distributions overlap.

[0056] The X-ray photographing device (20) can control only some of the X-ray sources to be turned on so that the X-rays emitted from the X-ray sources that are turned on do not repeatedly photograph the object to be photographed. For example, the X-ray photographing device (20) can photograph the object to be photographed by turning on a first X-ray source, a second X-ray source, and a third X-ray source having a predetermined interval among a plurality of X-ray sources included in the X-ray generator (210).

[0057] Thereafter, the X-ray photographing device (20) can sequentially turn on the fourth X-ray source, the fifth X-ray source, and the sixth X-ray source, which are located one space to the right of the first to third X-ray sources, to photograph the object to be photographed. In addition, the X-ray photographing device (20) can sequentially turn on the seventh X-ray source, the eighth X-ray source, and the ninth X-ray source, which are located one space to the right of the fourth to sixth X-ray sources, to photograph the object to be photographed.

[0058] Meanwhile, the X-ray photographing device (20) can simultaneously send a predetermined signal to the X-ray detector (230) when one or more X-ray sources are turned on, and can acquire and store projection data each time each X-ray source is turned on.

[0059] Meanwhile, as illustrated in FIG. 3, the X-ray generator (210) may have a plurality of X-ray sources (211) arranged in a two-dimensional array. The X-ray photographing device (20) may capture an X-ray image by controlling each of the plurality of X-ray sources (211) to be turned on or off in a first direction (u) or a second direction (v). Accordingly, the X-ray generator, in which the plurality of X-ray sources are arranged in a one-dimensional line shape, may capture an object to be captured with the same effect as capturing the object while moving horizontally.

[0060] The plurality of projection data may be an X-ray projection image in which each of the plurality of X-ray sources of the X-ray generator (210) is sequentially turned on or off in the first direction (u) or the X-ray generator (210) moves horizontally in the second direction (v) and the emitted X-rays are detected and projected by the X-ray detector (230).

[0061] The imaging device (20) can reconstruct a 2D or 3D X-ray image, which is a cross-sectional image of the object to be photographed, based on a plurality of projection data (700).

[0062] Referring to FIG. 4, the X-ray imaging device (20) may include an X-ray generator (210), an X-ray detector (820), a memory (250), and a processor (870).

[0063] The X-ray generator (210) may include a plurality of X-ray sources. The plurality of X-ray sources may be arranged in a one-dimensional line shape or in a two-dimensional array shape.

[0064] As another example, the X-ray generator (210) may include an X-ray source. The X-ray source may be configured to be movable along a plane parallel to the X-ray detector (230).

[0065] Meanwhile, the X-ray generator (210) may include a plurality of X-ray sources, as shown in FIGS. 2 and 6, and the plurality of X-ray sources may be arranged at regular intervals in a tube manner or an array manner.

[0066] The plurality of X-ray sources provided in the X-ray generator (210) of the present invention can be configured to irradiate X-rays having different energies.

[0067] A method for determining the type and thickness of a material of a subject by irradiating X-rays with multiple energies using multiple X-ray sources will be described in more detail later.

[0068] The X-ray detector (230) can generate an electrical signal corresponding to the dose of the X-rays transmitted. The X-ray detector (230) can generate projection data by generating the electrical signal.

[0069] The memory (250) stores programs for each signal processing and control within the processor (270), and can store signal-processed images, voices, or data signals, etc. The memory (250) can store a plurality of projection data.

[0070] The processor (870) can control the movement of the X-ray generator (210) or the X-ray detector (230), or control the on or off of the X-ray source of the X-ray generator (210) when the X-ray source is positioned at a desired location.

[0071] Additionally, the processor (870) can store a plurality of projection data generated from the X-ray detector (230) in the memory (250).

[0072] Additionally, the processor (870) can reconstruct a plurality of projection data into a 2D or 3D X-ray image (tomographic image), which is a cross-sectional image of the photographing target. For example, the processor (870) can apply a predetermined reconstruction algorithm based on a plurality of projection data to generate a 2D or 3D X-ray tomographic image.

[0073] FIG. 5 is a drawing illustrating a case where a conventional single X-ray generator exists, and FIGS. 6 and 7 are conceptual diagrams for explaining a method of taking a tomographic image using multi-energy X-rays of the present invention.

[0074] The X-ray generator (210) included in the X-ray photographing device of the present invention may include a plurality of X-ray sources that irradiate X-rays.

[0075] The X-ray detector (230) can detect X-rays transmitted through a subject by the X-ray generator (210) and generate projection data.

[0076] The processor (870) can generate a tomographic image (X-ray image) based on projection data generated through the X-ray detector (230).

[0077] As previously discussed, the above projection data may be multiple.

[0078] The processor (870) of the X-ray imaging device of the present invention controls the X-ray generator to irradiate X-rays having different energies, and can measure the thickness of the subject based on a tomographic image generated using a plurality of projection data generated through the X-rays irradiated with the different energies.

[0079] Referring to FIG. 5, conventionally, a single X-ray generator was used to generate a cross-sectional image of a subject, and thus only X-rays having one energy were used.

[0080] Examination using a single X-ray generator can extract internal structural information without destroying the examination subject through the amount of X-ray absorbed.

[0081] However, since the resulting image only allows for the average value of the X-ray absorption characteristics of the material in the thickness direction to be confirmed, the location of foreign substances in different planes cannot be identified. In addition, although an examination using a single X-ray generator can measure the thickness of a single / identical material, there is a possibility of an error in the thickness measurement if a foreign substance is present.

[0082] Meanwhile, the present invention can provide a multi-energy X-ray imaging device that irradiates X-rays having different energies.

[0083] For example, referring to FIG. 6(a), the processor (870) can control the X-ray generator (210) to cause a plurality of X-ray sources (601, 602, 603, 604, 605) to irradiate X-rays having a first energy (e.g., 20 kVp).

[0084] The processor (870) can control the X-ray detector (230) to obtain a plurality of first projection data in which the X-ray of the first energy has passed through the subject (220).

[0085] Thereafter, as illustrated in FIG. 6(b), the processor (870) can control the X-ray generator so that, after irradiating an X-ray having a first energy, the plurality of X-ray sources irradiate an X-ray having a second energy (e.g., 50 kVp) different from the first energy.

[0086] The processor (870) can control the X-ray detector (230) to obtain a plurality of second projection data in which the X-ray of the second energy has passed through the subject.

[0087] The processor (870) can control the X-ray generator so that the plurality of X-ray sources (601, 602, 603, 604, 605) sequentially irradiate X-rays having the first energy.

[0088] Additionally, the processor (870) can control the X-ray generator to sequentially irradiate X-rays having the second energy after the plurality of X-ray sources (601, 602, 603, 604, 605) sequentially irradiate X-rays having the first energy.

[0089] Accordingly, the processor (870) can obtain the plurality of first projection data as X-rays having the first energy are sequentially irradiated from the plurality of X-ray sources, and can then obtain the plurality of second projection data as X-rays having the second energy are sequentially irradiated from the plurality of X-ray sources.

[0090] As another example, as illustrated in FIG. 7, the plurality of X-ray sources may include at least one first X-ray source (601, 603, 605) configured to irradiate X-rays having a first energy and at least one second X-ray source (602, 604) configured to irradiate X-rays having a second energy different from the first energy.

[0091] The first X-ray source and the second X-ray source may be arranged alternately. In addition, since the energy of the X-ray source output by the first X-ray source and the second X-ray source may be determined by the control of the processor (870), the positions of the first X-ray source and the second X-ray source may be changed depending on the size of the energy to be output.

[0092] The processor (870) can control a plurality of X-ray sources so that a first X-ray source irradiated with X-rays having the first energy and a second X-ray source irradiated with X-rays having the second energy are arranged alternately.

[0093] The processor (870) can sequentially irradiate the first X-ray source and the second X-ray source. For example, the processor (870) can control the X-ray generator to irradiate the second X-ray source after irradiating the first X-ray source.

[0094] The processor (870) can acquire first projection data by irradiating the first X-ray source (601), and then acquire second projection data by irradiating the second X-ray source (602). Next, the processor (870) can sequentially acquire first projection data captured at a different angle by irradiating the first X-ray source (603), and then acquire second projection data captured at a different angle by irradiating the second X-ray source (604).

[0095] The processor (870) can generate a first tomographic image captured through X-rays having the first energy based on the plurality of first projection data, and can generate a second tomographic image captured through X-rays having the second energy based on the plurality of second projection data.

[0096] The subject (220) may include multiple substances.

[0097] Here, multiple substances may have different X-ray absorption rates (or X-ray transmittances) depending on the energy of the X-rays.

[0098] The processor (870) can measure the types and thicknesses of multiple materials included in the subject by using multiple tomographic images (a first tomographic image obtained by irradiating the subject with X-rays of a first energy and a second tomographic image obtained by irradiating the subject with X-rays of a second energy) obtained by irradiating the subject with X-rays of different energies.

[0099] The processor (870) can calculate the difference in intensity between the first tomographic image and the second tomographic image based on a first tomographic image obtained by irradiating the subject with X-rays having a first energy and a second tomographic image obtained by irradiating the subject with X-rays having a second energy different from the first energy.

[0100] As previously discussed, the absorption rate (or transmittance, attenuation coefficient, etc.) of X-rays contained in a subject may vary depending on the energy of the X-rays. Accordingly, when X-rays having different energies are irradiated, the intensity (or brightness) in the cross-sectional image generated for each energy may vary depending on the material.

[0101] The processor (870) calculates the intensity difference between a first tomographic image obtained by irradiating X-rays having a first energy and a second tomographic image obtained by irradiating X-rays having a second energy, and can measure the types and thicknesses of multiple materials included in the subject based on the difference in intensity.

[0102] The X-ray photographing device of the present invention can obtain a cross-sectional image for each location using two or more X-ray sources (or two or more X-ray generators), and then obtain information in the depth direction within the inspection target (subject) through image reconstruction.

[0103] In this case, the X-ray photographing device of the present invention can accurately measure the type and size of a substance contained in a subject by utilizing the difference in X-ray absorption characteristics according to the energy of the substance by using two different energies.

[0104] In particular, according to the present invention, the X-ray photographing device of the present invention can accurately measure the thickness of a target material to be measured by excluding foreign substances when foreign substances are present, thereby maximizing the efficiency of the inspection.

[0105] As examined in Fig. 7, the X-ray imaging device of the present invention can obtain a multi-energy tomographic image by alternately arranging X-ray sources having two or more energies.

[0106] In this case, the tomographic image acquired using high energy does not contain the information of the tomographic image acquired when shooting with low energy, and the same problem occurs in the opposite case.

[0107] To solve this, the X-ray imaging device of the present invention can supplement insufficient information by generating an image acquired using a second energy (high energy) from an image acquired using a first energy (low energy), and vice versa.

[0108] Through this, the present invention can reduce the shooting time and reduce the size of the system.

[0109] FIGS. 8, 9, 10, 11, 12, and 13 are conceptual diagrams illustrating a method for generating a tomographic image and determining the thickness and type of a material using multi-energy X-rays according to an embodiment of the present invention.

[0110] Figures 9 and 10 are conceptual diagrams showing a case where a conventional single X-ray source is used.

[0111] Referring to Fig. 10, in the case of a conventional technique using a single X-ray source, an X-ray image (tomogram) is obtained by irradiating X-rays having a single energy (S1010), and the thickness of the subject is calculated using the difference in intensity (S1020).

[0112] When using single-energy X-rays, the intensity of the tomographic image is determined by the thickness of the entire material.

[0113] The thickness of a material can be calculated using the intensity of the image.

[0114] If it is a single / same material, thickness measurement is possible, but if multiple materials are mixed, it becomes difficult to measure the overall thickness and the thickness of each material depending on the characteristics of each material (thickness, density, etc.).

[0115] FIG. 11 and FIG. 12 are drawings for explaining a non-destructive inspection method using multi-energy X-rays of the present invention.

[0116] Referring to Figure 11, a difference in image quality according to X-ray energy occurs depending on the physical characteristics (thickness, density, etc.) of the photographing target (subject).

[0117] When a subject contains multiple materials (multiple substances), the processor (870) can calculate thickness information of each material by using images obtained using X-rays of different energies and intensity differences.

[0118] Additionally, the processor (870) can obtain the absorption difference according to the thickness difference of each material in the overlapping photographing target in the form of an image.

[0119] Referring to FIG. 12, the processor (870) can obtain a first tomographic image through a first energy (low energy) X-ray (S1210) and obtain a second tomographic image through a second energy (high energy) X-ray (S1220).

[0120] Afterwards, the processor (870) can calculate the difference in intensity of each energy image (S1230).

[0121] The processor (870) can calculate the information on each material (type of material, Ni, Al, etc.) and thickness included in the subject by applying an analysis algorithm (S1240, S1250).

[0122] Referring to FIG. 13, the processor (870) can perform clustering by material region based on a first tomographic image (1300) obtained by irradiating an X-ray having a first energy (e.g., 20 kVp) to a subject and a second tomographic image (1310) obtained by irradiating an X-ray having a second energy (e.g., 50 kVp) different from the first energy.

[0123] The processor (870) can perform dual energy image processing using the first tomographic image (1300) and the second tomographic image (1310). In the dual energy image processing, the image domain can be transformed, and the material discrimination ability can be improved through dynamic range adjustment.

[0124] The processor (870) can perform image domain transformation that applies an attenuation coefficient to intensity and improve the ability to distinguish between objects through dynamic range adjustment.

[0125] Thereafter, the processor (870) can perform a noise reduction process. Specifically, the processor (870) can remove quantum noise and perform anti-scattering.

[0126] Thereafter, the processor (870) may perform clustering by material region (by substance). Here, clustering may refer to a method of classifying data into several groups based on concepts such as similarity. In an X-ray imaging device, clustering may be performed by material (by material region) in a tomographic image based on at least one of an attenuation coefficient and the intensity of the transmitted X-ray (or intensity information or brightness information in a tomographic image).

[0127] The processor (870) can calculate an X-ray attenuation coefficient for each material using the clustered image (1320). For example, the processor (870) can analyze cluster intensity using the clustered image and calculate and correct the X-ray attenuation coefficient.

[0128] The processor (870) can perform clustering on substances whose attenuation coefficients fall within a predetermined range, and can classify (determine) substances falling within the predetermined range as a single substance. In this way, the processor (870) can classify multiple substances falling within a predetermined range through a clustering operation, and can determine the type of each substance based on the attenuation coefficient.

[0129] Additionally, the processor (870) can generate a thickness map (1330) for measuring the thickness of multiple materials included in the subject using the clustered image.

[0130] Thereafter, the processor (870) can measure the thickness of each material through the thickness map. The processor (870) can calculate the thickness for a desired line by applying an LPF (Low Pass Filter).

[0131] In this way, the X-ray photographing device of the present invention can perform thickness measurement of a material using a multi-energy X-ray generator by applying a thickness measurement algorithm for each coating material through an X-ray generator and an X-ray detector that generate two or more different energies.

[0132] As previously discussed, the present invention may include an X-ray generator that generates two or more different energies, and the X-ray generator may sequentially generate high-energy and low-energy X-rays, respectively, or may be implemented in the form of an array generator that generates high-energy and low-energy X-rays, respectively.

[0133] Additionally, the X-ray generator may have multiple X-ray sources arranged in a cross-section to alternately generate high-energy and low-energy X-rays, and may alternately generate high-energy and low-energy X-rays.

[0134] The arrangement of two or more X-ray sources included in the X-ray generator may include a straight line shape, a partial arch shape, or the like.

[0135] The X-ray detector may include a direct detection method and an indirect detection method, and may have a linear or planar detection area. In addition, the X-ray detector may apply a detection method of an accumulation method and a photon counting method.

[0136] An X-ray detector using a direct detection method may include a material 1 for a direct detection method that forms ionizing radiation into electron-hole pairs, and the material 1 may include the following.

[0137] [Material 1] Amorphous Selenium, Perovskite, CdTe, CdZnTe

[0138] An X-ray detector using an indirect detection method may include a scintillator material 2 for an indirect detection method that converts ionizing radiation into the visible light and infrared regions, and the material 2 may include:

[0139] [Material 2] CsI:Tl, GOS, perovskite

[0140] The above perovskite material may include a perovskite compound represented by the following chemical formula 1.

[0141] [Chemical Formula 1] MAPbX3, FA-MA-CsPbX3 (X = I, Br, Cl)

[0142] The device for measuring the thickness of a material using the multi-energy X-ray generator of the present invention may include a method for improving the low signal-to-noise ratio characteristics of a multi-energy X-ray image.

[0143] The above coating material-specific thickness measurement algorithm can separately measure the thickness of each of two or more materials.

[0144] Meanwhile, referring to FIG. 8, the processor (870) of the present invention may include an X-ray generator and detector driving unit (910) and an image processing and calculation unit (920).

[0145] The above X-ray generator and detector driving unit (910) and image processing and calculation unit (920) may be hardware modules provided in the processor (870), or may be understood as blocks componentized in software.

[0146] The above X-ray generator and detector driving unit (910) may include an X-ray driving unit (xray generator 1, …, xray generator n), an X-ray driving unit control unit (xray generator controller), a main controller, an X-ray detector panel, and a signal read-out circuit.

[0147] The X-ray driving unit (x-ray generator 1, …, x-ray generator n) generates X-rays corresponding to different arbitrary tube voltages (kVp) and tube currents (mA) from one or more arbitrary number of X-ray generators. The tube voltage and tube current settings of the X-ray generator may vary depending on the type and characteristics of the material to be detected.

[0148] The X-ray generator controller changes the tube voltage and tube current settings of any number of X-ray generators or sequentially drives each X-ray generator and controls X-ray irradiation for any period of time.

[0149] An x-ray detector panel (x-ray detector) converts x-rays into visible light and then converts them into electrical signals, or converts x-rays directly into electrical signals.

[0150] A signal read-out circuit can read charge information formed and stored by X-rays from an X-ray detection panel and generate image data (projection data or tomographic image) of a subject.

[0151] The main controller controls and synchronizes the operations between each X-ray drive unit, detection panel, and signal output circuit.

[0152] The image processing and calculation unit (920) may include an image data pre-processing module, an image clustering module, an image analysis module, an attenuation factor correction module, a thickness map generation module, and a post processing module.

[0153] The image data preprocessing module performs preprocessing on images formed by each tube voltage and tube current. The image data preprocessing module removes image noise and improves image quality, thereby enhancing the accuracy of subsequent processing.

[0154] The image clustering module clusters images by region using image brightness information, etc. based on preprocessed images.

[0155] The image analysis module analyzes the ratio and characteristics of brightness information for images generated by X-ray generators of different energies for each clustered area to identify the type of material in each clustered area.

[0156] The attenuation factor correction module corrects the attenuation factor using the material-specific attenuation factor corresponding to each clustering area and the image analysis results.

[0157] The thickness map generation module calculates the thickness of the subject and creates a map using the calculated attenuation coefficient and image brightness information.

[0158] The post-processing module can improve thickness accuracy by removing noise components and adjusting scale, etc. through a post-processing process on the thickness map, and output thickness information.

[0159] According to the present invention, the accuracy of thickness measurement for each layer can be improved by distinguishing materials using multi-energy X-rays.

[0160] The present invention can non-destructively determine the type of material based on the fact that the absorption rate of X-rays varies depending on the material using multi-energy X-rays.

[0161] The present invention can provide a signal processing processor for improving the low signal-to-noise ratio (SNR) of multi-energy X-ray images.

[0162] Further scope of the applicability of the present invention will become apparent from the detailed description below. However, since various modifications and variations within the spirit and scope of the present invention will become apparent to those skilled in the art, it should be understood that the detailed description and specific examples, such as preferred embodiments of the present invention, are given by way of example only.

[0163] The present invention described above can be implemented as computer-readable code on a medium in which a program is recorded. Computer-readable media include all types of recording devices that store data that can be read by a computer system. Examples of computer-readable media include hard disk drives (HDDs), solid state disks (SSDs), silicon disk drives (SDDs), ROMs, RAMs, CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, etc., and also include media implemented in the form of carrier waves (e.g., transmission via the Internet). In addition, the computer may include a control unit (180) of a terminal. Therefore, the above detailed description should not be construed as limiting in all respects, but should be considered as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are intended to be included in the scope of the present invention.

Claims

1. An X-ray generator including a plurality of X-ray sources for irradiating X-rays; An X-ray detector that detects X-rays transmitted through a subject by the X-ray generator and generates projection data; and A processor for generating a tomographic image based on projection data generated through the X-ray detector is included. The above processor, An X-ray photographing apparatus characterized in that the X-ray generator is controlled to irradiate X-rays having different energies, and the thickness of the subject is measured based on a tomographic image generated using a plurality of projection data generated through the X-rays irradiated with the different energies.

2. In paragraph 1, The above processor, Controlling the X-ray generator so that the plurality of X-ray sources irradiate X-rays having a first energy, An X-ray photographing apparatus characterized in that the X-ray detector is controlled so that the X-ray of the first energy obtains a plurality of first projection data transmitted through the subject.

3. In paragraph 2, The above processor, After irradiating the X-ray having the first energy, the X-ray generator is controlled so that the plurality of X-ray sources irradiate the X-ray having a second energy different from the first energy, An X-ray photographing apparatus characterized in that the X-ray detector is controlled so that the X-ray of the second energy obtains a plurality of second projection data transmitted through the subject.

4. In paragraph 2, An X-ray imaging device, characterized in that the processor controls the X-ray generator so that the plurality of X-ray sources sequentially irradiate X-rays having the first energy.

5. In paragraph 3, An X-ray imaging device, characterized in that the processor controls the X-ray generator so that the plurality of X-ray sources sequentially irradiate X-rays having the second energy.

6. In paragraph 1, The above multiple X-ray sources are, At least one first X-ray source configured to irradiate X-rays having a first energy; and An X-ray imaging device characterized by comprising at least one second X-ray source configured to irradiate X-rays having a second energy different from the first energy.

7. In paragraph 6, An X-ray photographing device, characterized in that the first X-ray source and the second X-ray source are arranged alternately.

8. In paragraph 6, The above processor, An X-ray imaging device characterized in that the X-ray generator is controlled to irradiate the second X-ray source after irradiating the first X-ray source.

9. In paragraph 3, The above processor, Based on the plurality of first projection data, a first tomographic image is generated by taking an X-ray having the first energy, An X-ray photographing apparatus characterized in that it generates a second tomographic image captured by an X-ray having the second energy based on the plurality of second projection data.

10. In paragraph 1, The above subject contains multiple substances, The above multiple substances have different X-ray absorption rates depending on the energy of the X-ray. The above processor is an X-ray imaging device characterized in that it measures the types and thicknesses of multiple materials included in the subject by using multiple tomographic images acquired by irradiating the subject with X-rays having different energies.

11. In paragraph 1, The above processor, Based on a first tomographic image obtained by irradiating the subject with X-rays having a first energy and a second tomographic image obtained by irradiating the subject with X-rays having a second energy different from the first energy, the difference in intensity between the first tomographic image and the second tomographic image is calculated, An X-ray imaging device characterized by measuring the types and thicknesses of multiple substances contained in the subject based on the difference in intensity.

12. In paragraph 1, The above processor, An X-ray imaging device characterized in that clustering is performed by material based on a first tomographic image obtained by irradiating the subject with X-rays having a first energy and a second tomographic image obtained by irradiating the subject with X-rays having a second energy different from the first energy.

13. In paragraph 12, The above processor, An X-ray imaging device characterized by calculating an X-ray attenuation coefficient for each material using a clustered image.

14. In paragraph 12, The above processor, An X-ray imaging device characterized by generating a thickness map for measuring the thickness of multiple substances included in the subject using a clustered image.

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