WO2018004085A1

WO2018004085A1 - Non-rotating oblique-type ct device and method for restoring three-dimensional internal shape image of subject using same

Info

Publication number: WO2018004085A1
Application number: PCT/KR2016/014338
Authority: WO
Inventors: 진경찬; 이성호
Original assignee: 한국생산기술연구원
Priority date: 2016-06-29
Filing date: 2016-12-07
Publication date: 2018-01-04
Also published as: KR20180002956A; KR101818639B1

Abstract

The present invention relates to a non-rotating oblique-type CT device comprising: a stage; an incident radiation forming portion for forming incident radiation to be emitted to a subject; a projection data detecting portion installed opposite the incident radiation generating portion with reference to the position of the subject so as to acquire a projection data set generated as the incident radiation is projected onto the subject; and a three-dimensional image processing portion for processing the projection data set and thereby restoring the three-dimensional internal shape image of the examined area, wherein the incident radiation is formed as a pattern that is proximate to the subject and is radiated from a radiating source positioned at a location spaced from the center position of the examined area toward the outer periphery, and the projection data set is acquired all at once. The present invention is advantageous in that neither the radiation source nor the subject rotates, and the detector acquires angle-specific projection data all at once and parallel-processes the same, thereby shortening the overall examination rate.

Description

Non-rotating oblique type CT device and 3D internal shape image restoration method

The present invention relates to a non-rotational oblique type CT device and a method for restoring a three-dimensional internal shape image of an inspected object using the same. More particularly, the radiation source and the inspected object do not rotate, and the detector is projected by angle. A non-rotating oblique type CT device having an advantage of shortening the overall inspection speed by acquiring data at once and parallel processing thereof, and a method of restoring a three-dimensional internal shape image of a subject using the same.

The CT (Computed Tomography) device rotates the output source of radiation such as X-rays and the receiving portion of the radiation that has passed through the subject, and processes the collected data to produce two- and three-dimensional images of the subject. Acquisition device.

The amount of radiation transmitted to the subject depends on the material and the distance of the subject placed on the path of radiation, and the graph shows the amount of radiation in terms of the angle of rotation, resulting in a sinogram. In addition, the sinogram can be subjected to a specific operation to obtain a three-dimensional image of the object under test.

Although such a CT device is widely used in the medical field, it can also be utilized in fields such as quality inspection of precise electronic parts. In particular, in recent years, a three-dimensional packaging technology in which a plurality of chips are vertically mounted in one package is widely used, and it is possible to inspect whether a plurality of chips are electrically connected using a CT device.

In Korean Patent Registration No. 10-1146883 (hereinafter referred to as Reference 1), a non-rotating CT system is implemented by using a plurality of X-ray generators and detectors, and in particular, X-ray images of various objects can be obtained at an arbitrary viewpoint. After obtaining every moment, using a minimum number of two-dimensional X-ray images and image interpolation techniques to provide a non-rotating CT system that can build a CT image for every point of the object.

Although the technique of Citation 1 implements a non-rotating CT system using a large number of X-ray generators, the X-ray generator and the detector are positioned around the object, so that a tomographic image with high resolution can be obtained. The first problem that cannot be obtained, and the second problem that the configuration of the equipment is complicated in that a number of X-ray generators and detectors must be provided in order to construct an accurate tomographic image.

The present invention has been made in order to achieve the above technical problem, an oblique type CT device for restoring a three-dimensional internal shape image of the inspection target area of the subject, the stage 20, the subject is placed on the subject An incident radiation forming unit forming an incident radiation to be irradiated to the projection unit, a projection data detection unit and a projection installed on the opposite side of the radiation generating unit on the basis of the position of the inspected object, and obtaining a projection data set generated by passing the incident radiation through the inspected object A three-dimensional image processing unit for processing the data set to restore a three-dimensional internal shape image of the inspected region, wherein the incident radiation is located at a point proximate to the inspected object and spaced outward from the center position of the inspected region; It is formed as a pattern radiated from a located radiation source, and the projection data set proposes a configuration that can be acquired at a time. The non-rotational oblique type CT device having such a configuration and a method of restoring a three-dimensional internal shape image of the inspected object by using the same method do not rotate both the source and the inspected object, and acquire projection data on the inspected area at once. Parallel processing can be performed on the obtained plurality of projection data, which can significantly shorten the total time required to restore the 3D tomographic image for the inspected region than in the conventional CT apparatus.

The present invention can prevent the rotation of both the source and the inspected object, obtain projection data for the inspected area at a time, and perform parallel processing on the obtained plurality of projection data, thereby providing a conventional CT device configuration. The second effect is that the total time required to reconstruct the 3D tomography image for the inspection area can be significantly shortened, and the second effect that the tomographic image can be obtained at high resolution through the configuration of an oblique type CT device. Have

1 is a schematic diagram of a non-rotating oblique type CT apparatus according to an embodiment of the present invention.

2 is a schematic diagram illustrating parameters applied to sub-incident radiation and sub-incident radiation according to an embodiment of the present invention.

3 is a schematic diagram for explaining a method of forming a first overlapped region that may be formed by first incident radiation from a first radiation station according to an embodiment of the present invention.

4 is a schematic diagram for explaining a method of forming a second overlapped region that can be formed by second incident radiation from a second radiation station according to an embodiment of the present invention.

5 is a schematic diagram showing an embodiment of the incident radiation forming unit of the present invention.

Fig. 6 is a block diagram illustrating a process for reconstructing a tomographic image by parallel processing a plurality of projection data for a region to be inspected temporarily acquired by the CT apparatus of the present invention.

The present invention devised to solve the above problems is an oblique type CT device for restoring a three-dimensional internal shape image of an inspection subject area, the stage 20 on which the subject is placed, on the subject. An incident radiation forming unit forming an incident radiation to be irradiated, a projection data detecting unit and projection data which are installed opposite to the radiation generating unit on the basis of the position of the inspected object and obtain a projection data set generated by passing the incident radiation through the inspected object A three-dimensional image processing unit for processing the set to restore a three-dimensional internal shape image of the inspected region, wherein the incident radiation is located at a point proximate to the inspected object and spaced outwardly from the center position of the inspected region; It is formed as a pattern radiated from a radiation source, and the projection data set proposes a configuration that can be obtained at a time.

In addition, the projection data set is a set of a plurality of projection data obtained by dividing a single whole projection data detected at a time on the projection data detection unit, wherein each of the plurality of projection data, the incident radiation is virtual The incident angle of each of the plurality of sub-incident radiations divided and set to the inspection region may be reflected.

In addition, the radiation source may be two or more radiation sources.

The radiation source may be two radiation sources (a first radiation station and a second radiation station), and the incident radiation may correspond to the first radiation station and the second radiation station, respectively. The second incident radiation may be a second incident radiation, and the plurality of subincident radiations may be a first subincident radiation set and a second subincident radiation set corresponding to each of the first incident radiation and the second incident radiation.

The incident radiation forming unit may include a radiation source unit and a radiation flux adjusting unit configured to form the incident radiation incident on the test object by adjusting a radiation flux from the radiation source unit.

Further, the radiation flux adjusting portion may be made of a radiation shielding material, has an opening, and the radiation passing through the opening may function as the incident radiation.

In addition, the radiation source portion may comprise a single radiation source.

The projection data detection unit may be shaped to cover an upper portion of the inspected object.

The present invention comprises the steps of: (1) dividing the incident radiation to set the plurality of subincident radiations, and wherein each of the plurality of subincident radiations is given information on an incident angle to the subject under test, (2) Measuring the subject penetration region for each of the plurality of subincident radiations, and (3) determining a region (overlapping region) in which all of the subject penetration regions with respect to each of the plurality of subincident radiations overlap each other. And (4) a method for setting a region to be inspected of a non-rotating oblique type CT device, including determining the overlapped region as the region to be inspected.

In addition, the present invention, (a) dividing the single total projection data 70, deriving sub-projection data corresponding to each of the plurality of sub-incident radiation, (b) each of the plurality of sub-incident radiation Extracting, from the sub-projection data for, the portions actually transmitted and detected in the inspected region, and (c) designating the portions extracted in the (b) as the plurality of projection data for the inspected region. It provides a method of obtaining a plurality of projection data for the inspected area comprising the step of.

In addition, the present invention (1) by dividing the first incident radiation and the second incident radiation to set the first sub-radiation radiation set and the second sub-incidence radiation set, the first sub-radiation radiation set Receiving a plurality of sub-incident radiations constituting the plurality of sub-incident radiations and the second sub-incident radiation set, each of which is provided with information on an incident angle to the subject, (2) forming the first sub-incident radiation set Measuring the subject penetration region for each of the plurality of sub-incident radiations constituting the plurality of sub-incident radiations and the plurality of sub-incident radiation sets, (3) the plurality of sub-incident radiation sets A plurality of regions (first overlapping regions) for overlapping each of the inspected object transmission regions with respect to each of the incident radiations, and constituting the second sub-incident radiation set; Determining a region (second overlapping region) in which all of the subject penetrating regions of the sub-incident radiation of each overlap each other (4) examining the overlapping region of the first overlapping region and the second overlapping region Provided is a method for setting a region to be inspected for a non-rotating oblique type CT device including determining the region.

In addition, the first overlapping region and the second overlapping region may be set to be the same.

In addition, the present invention, (i) mounting the subject to the stage 20, (ii) the incident radiation forming unit forms the incident radiation, the incident radiation is transmitted to the subject, (iii) the projection data detection unit 90 detects the single whole projection data 70 at a time, and (iv) the three-dimensional image processing unit processes the single whole projection data 70 to A method of restoring a three-dimensional internal shape image of an inspected object by using a non-rotating oblique type CT device, comprising: restoring a three-dimensional internal shape image of a region to be inspected.

Also, the step (iv) may include: (iv-1) the three-dimensional image processing unit processing the single whole projection data 70 to generate the plurality of projection data; and (iv-2) the three Performing filtering on each of the plurality of pieces of projection data by the dimensional image processing unit, (iv-3) performing geometric transformation on each of the plurality of filtered pieces of projection data by the three-dimensional image processing unit, and ( and iv-4) performing, by the three-dimensional image processing unit, rotation angle transformation on each of the plurality of pieces of projection data on which the geometric transformation has been performed. Each of the three projection data may be processed in parallel.

The method may further include storing the plurality of pieces of projection data in a memory between the step (iv-1) and the step (iv-2).

Hereinafter, with reference to the accompanying drawings will be described the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, coupled)" with another part, it is not only "directly connected" but also "indirectly connected" with another member in between. "Includes the case. In addition, when a part is said to "include" a certain component, this means that unless otherwise stated, it may further include other components rather than excluding the other components.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, the term 'comprises' or 'including' is intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and that one or more other features It should be understood that it does not exclude in advance the possibility of the presence or addition of numbers, steps, operations, components, parts or combinations thereof.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The oblique type CT apparatus of the present invention performs a function of restoring a three-dimensional internal shape image of an inspected region of the inspected object 10, and forms a stage 20 and an incident radiation forming unit 30 to form incident radiation. And a projection data detector 90 for obtaining a projection data set generated by transmission of incident radiation to the object 10 and a three-dimensional image for restoring a three-dimensional internal shape image of the object 10 by processing the projection data set. It has a processing unit as a main component. Since it is characterized in that a plurality of projection images of the inspected area of the inspected object 10 can be obtained at a time, once the plurality of projected images are obtained, the process is performed to process the three-dimensional image of the inspected object 10. The well-known structure can be applied to the detailed structure of the 3D image processing part which functions to restore | restore an internal shape image. However, since it is possible to acquire a plurality of projection images at a time, there is a characteristic that a tomographic image can be formed at a higher speed by processing them in parallel, which will be described separately.

The incident radiation is formed as a pattern emitted from a radiation source located at a point spaced apart from the center of the inspection target area, and the projection data set has a main feature of being acquired at a time. In particular, since the incident radiation is formed in a pattern radiated from a radiation source located at a point spaced apart from the center of the inspected region, the incident radiation is obliquely incident on the inspected region, which is the CT device of the present invention. Is the basis for being able to name the oblique type CT device.

The inspected object 10 may be a thin object such as a semiconductor device package, and when the present invention is used in the medical field, may be a human body or an animal.

The inspected region means a target region in which the restored three-dimensional image (image) can be obtained using the CT apparatus of the present invention. The inspected region may be the entire inspected object 10, but is limited to only a partial region of the inspected object 10.

An image is represented by a set of data consisting of pixels or voxels. The tomography image may be an image obtained by processing a projection data set by a specific algorithm.

Hereinafter, each component will be described in detail.

The projection data set is obtained by detecting the incident radiation to the object 10 and detecting the transmitted radiation by the projection data detection unit 90. The projection data set is composed of a plurality of projection data. A tomography image is obtained. The projection data set is a set of a plurality of projection data obtained by dividing a single whole projection data 70 detected at a time on the projection data detection unit 90, which will be described later.

The single whole projection data 70 is processed into a plurality of projection data and utilized. In the present invention, unlike the conventional CT apparatus, since the object and the incident radiation forming unit 30 do not perform any rotational behavior, the single whole projection data 70 is obtained at a time. Since the projection data set is obtained by processing the single whole projection data 70, it may be expressed that the projection data set is also acquired at a time. In other words, the temporary acquisition of the projection data set starts with acquiring a single whole projection data 70 detected at once on the projection data detection unit 90. Thereafter, the single whole projection data 70 is divided to form a plurality of projection data.

Further, each of the plurality of projection data reflects an angle of incidence of each of the inspected regions of the plurality of sub-incidence radiations in which the incidence radiations are virtually divided and set. Although the non-rotating oblique type CT apparatus of the present invention does not rotate both the radiation source and the inspected object 10, in order to obtain a three-dimensional tomographic image of the inspected region, a projection data set containing a kind of angle information is provided. Should get (In a typical CT device, projection data for rotational angles is obtained.) That is, the present invention should obtain projection images for each 'angle', and this 'angle' is a part of the non-rotating oblique type CT device of the present invention. It does not rotate, so that each of the plurality of sub-incidence radiations, which can be thought to be divided by the incident radiation, becomes 'an angle of incidence into the inspected region'.

The incident radiation is formed in a pattern radiating in all directions around the radiation source, and the plurality of sub-incident radiations are formed by virtually dividing the incident radiation. When the incident radiation is split and a plurality of subincident radiations are assumed to be virtual, the following two pieces of information should be considered. One is the angle of incidence of each of the plurality of sub-incidence radiations into the inspection region, and the other is the radiation angle width of each of the plurality of sub-incidence radiations. The former is angle information respectively given to a plurality of pieces of projection data (relative to the inspection subject area) obtained later, which is used as a parameter, and is information necessary for synthesizing a 3D tomography image for the inspection subject region. The latter is a concept similar to the center of radiation of radiation emitted in a cone form from a radiation source. The increment in the 'incidence angle into the inspection region of each of the plurality of subincident radiations' and the 'radiation angle width of each of the plurality of subincident radiations' may be set to be equal to each other, but may be set to be different. to be. In particular, when the radiation angle width is set larger than the increment, the subprojection data for each of the plurality of subincident radiations may overlap each other.

In the non-rotational oblique type CT apparatus of the present invention, a method of obtaining a plurality of projection data for a region to be inspected from a single whole projection data 70 is as follows. Only a plurality of projection data are determined by extraction).

First, by dividing a single whole projection data 70, subprojection data corresponding to each of the plurality of subincident radiations is derived. As described above, the plurality of subprojection data may overlap each other. In general, one sub-projection data (sub-radiation related) will be greater than or equal to one projection data (subject to inspection area), which is an area where the sub-incident radiation penetrates the object 10, This is because the projection data generated through the inspection target area is always included (or the same).

Second, among the sub-projection data for each of the plurality of sub-incident radiations, the portions actually transmitted and detected through the inspected region are extracted. It is because it is an object of the present invention to obtain a tomographic image of a region to be inspected, and thus data for a portion of the inspected object 10 that is not the region to be inspected is not necessary.

Third, the portions extracted in the second step are designated as a plurality of projection data for the inspected area. Each of the plurality of projection data has an angle of incidence into the inspected region of each of the plurality of subincident radiations as a parameter.

3 and 4, a description will be given of a method of presetting a region to be inspected for the inspected object 10, that is, a method of setting a plurality of pieces of projection data obtained so as to be for one inspected region. Shall be.

Such presetting may be performed by adjusting the spatial arrangement of the components of the present invention, such as the incident radiation forming unit 30 and the inspected object 10.

The general CT apparatus allows the radiation source 31a to rotate around the inspected object 10 or rotates the inspected object 10 about a predetermined rotation axis to secure projection data for each rotation angle. In both the object 10 and the radiation source do not rotate, nevertheless, projection data for each angle (incidence angle to the inspected region) (which is a plurality of projection data) must be obtained. Furthermore, even if a plurality of projection data for each incident angle is obtained, such a plurality of projection data should be obtained for one inspected area. Thus, the step of presetting should be preceded before acquiring a single whole projection data 70 so that the plurality of projection data obtained are for one inspected area.

Specifically, first, the incident radiation is divided so that a plurality of subincident radiations are set, so that each of the plurality of subincident radiations is given information on an incident angle with respect to the subject 10. In this case, the plurality of sub-incidence radiations are the same as those mentioned in the method for extracting the plurality of projection data from the single whole projection data 70 described above. 10) is given information on the angle of incidence.

Secondly, for each of the plurality of subincident radiations, the subject penetration region is measured. Each of the sub-incidence radiations is transmitted through the entire inspected object 10, because the actual need is limited to the projection data of the region to be inspected.

Third, a region (overlapping region) in which each of the subject penetrating regions for each of the plurality of sub-incident radiations overlaps is determined, and this overlapping region is determined as an inspection subject region. Thus, a plurality of projection data for the inspection target area are ready to be obtained.

Specifically, referring to FIG. 5, the radiation source is composed of two radiation sources (the first radiation station 41 and the second radiation station 42), and the incident radiation is the first radiation station 41 and the second radiation station. Corresponding to each of the small 42, the first incident radiation 50a and the second incident radiation are provided, and the plurality of sub-incident radiations corresponds to the first incident radiation 50a and the second incident radiation, respectively. In an embodiment in which the sub-incident radiation set and the second sub-incident radiation set are set, the method for setting the inspected area is as follows. Reference is now made to FIGS. 3 and 4.

First, a plurality of sub-incident radiations and a plurality of sub-incident radiations constituting the first sub-radiation radiation set by dividing the first incident radiation 50a and the second incident radiation, setting the first sub-radiation radiation set and the second sub-incidence radiation set. Each of the plurality of sub-incidence radiations constituting the second sub-incidence radiation set is given information on the angle of incidence of the object under test.

Second, for each of the plurality of sub-incident radiations constituting the first sub-incident radiation set and each of the plurality of sub-incident radiations constituting the second sub-incidence radiation set, the object to be inspected is measured.

Third, a plurality of sub-incidents forming a second set of sub-incidence radiations are determined by determining a region (first overlapping area) in which all of the subject-transmitted regions for each of the plurality of sub-incidence radiations constituting the first sub-incidence radiation set overlap each other. An area (second overlapping area) in which each of the inspected object transmissive areas for each of the radiations overlaps is determined. For example, if the first overlapped region is related to projection data (eg, n projection data) obtained by the first sub-incident radiation set having an incident angle of 0 to 90 degrees with respect to the object 10, The two overlapping regions are associated with projection data (for example, n projection data) obtained by the second sub-incident radiation set having an incident angle of 90 degrees to 180 degrees with respect to the inspected object 10.

Fourth, the overlapping area of the first overlapping area and the second overlapping area is determined as the inspected area. In this case, the number of projection data for the inspection target area is n + n, and these 2n projection data become 'plural projection data' which constitute the projection data set in the present invention. Of course, if the first overlapped area and the second overlapped area are set to be completely the same from the beginning, it is clear that the inspected area will be the first overlapped area (second overlapped area) itself.

The stage 20 is a structure in which the inspected object 10 is located, and it is preferable that the stage 20 is made of a material with which radiation is transmitted. In a typical CT apparatus, unlike the embodiment in which the stage 20 rotates about a predetermined axis of rotation, the stage 20 of the present invention does not rotate but maintains a fixed position with respect to the external absolute coordinate system. .

The incident radiation forming unit 30 performs a function of forming incident radiation to be irradiated on the subject 10, where 'forming' includes generating and adjusting the generated radiation to suit the purpose. Unlike in the general CT device, such as an X-ray generator or the like, which rotates a revolving pattern or the like about the object 10, the incident radiation forming unit 30 of the present invention is fixed with respect to the absolute coordinate system. Maintain the correct position.

The radiation source, which can be called the logical center of radiation of incident radiation, can consist of two or more radiation sources.

The reason why it is not preferable to constitute the radiation source with only one radiation station is to achieve the object of the present invention as follows.

For example, when one station is located at the center of the inspected object 10, overlapping areas are formed on the left and right sides of the station 10, but for two overlapping areas thus formed, 0 degrees for one. Only the projection data in the 90 degree view (the view from the incident side) in (the lack of projection data in the 90 degree to 180 degree view), and for the other, only the projection data in the 90 degree to 180 degree view As a result (lack of projection data in the 0 degree to 90 degree view), for both overlapping regions, a valid tomographic image cannot be obtained.

For this reason, the radiation source should be composed of two or more radiation sources, and furthermore, by properly setting the positions of the radiation sources and the inspected object 10, effective tomographic images of the inspected region of the inspected object 10 can be obtained. If so, two radiation sources may be sufficient. That is, it is preferable to comprise a radiation source with two radiation sources (the 1st radiation station 41 and the 2nd radiation station 42).

In the embodiment where two radio stations (the first radio station 41 and the second radio station 42) are applied, the two radio stations are located on opposite sides with respect to the inspection target area of the inspected object 10. Can be set to Preferably, the first radioisotope 41 and the second radioisotope may be located at symmetrical positions with respect to the inspection target area. In this case, the first radio station 41 may be involved in the view from 0 degrees to 90 degrees, and the second radio station 42 may be involved in the views from 90 degrees to 180 degrees. At this time, if the overlapping regions (the first overlapping region and the second overlapping region) determined for each of the first radiation station 41 and the second radiation station 42 are set to coincide with each other (the first nesting area and the second nesting area) The area can be named as the inspection area, so that projection data having a view from 0 to 180 degrees can be obtained as a result of the inspection area. It will be possible to acquire tomographic images of the area. However, when the first overlapping region and the second overlapping region are not formed so that the first overlapping region and the second overlapping region are the same, the first overlapping region and the second overlapping region are overlapped with each other. It is not necessary to obtain the area again and to make it an area under test.

However, with respect to the projection data that can be obtained, it is not always possible to obtain projection data having a view from 0 to 180 degrees as mentioned above. In the embodiment in which the first and

second radiation stations

41 and 2 are applied, the inspection target area is set as a narrower area inward than the installation positions of the first and

second radiation stations

41 and 42. The tomographic image obtained for the region to be inspected may be obtained by, for example, synthesizing projection data having a view from 30 degrees to 150 degrees. In this case, since there is no projection data having views of 0 degrees to 30 degrees and 150 degrees to 180 degrees, the accuracy of the tomographic image may be slightly deteriorated, but the inspected object 10 such as a circuit board is thin and narrow. In this case, it is considered that the degree of such a decrease is not large.

Furthermore, with respect to the installation positions of the radiation sources (the first radiation station 41 and the second radiation station 42) at the position of the inspected object 10, it may be considered to place the radiation source at the edge of the inspected object 10. When the radiation source is located inside the edge of the inspected object 10, the overlapping regions generated by the first radiation station 41 and the second radiation station 42 are hardly set to coincide. This is because the area must be narrowly formed. Accordingly, it may be considered to place each of the first and

second radiation sources

41 and 42 near both edges of the object 10. However, it is considered that the inspected region is generally limited to a part of the inner region of the inspected object 10.

The incident radiation forming unit performs a function of forming incident radiation (forming a radiation source).

The incident radiation forming unit 30 is positioned so that the incident radiation can be incident close to the test subject 10. The CT apparatus of the present invention can be regarded as an oblique type, in which the radiation source (radiation station) needs to be located in close proximity to the inspected object 10 (stage 20). This is because the incident radiation from the radiation source (radiation station) located close to the X-ray is incident at an angle to the inspected region of the inspected object 10 as a result.

In connection with the incident radiation and the radiation source (radiation station) described above, it is assumed that the incident radiation is emitted from the radiation source (radiation station).

As an example of the incident radiation forming unit 30, two or more radiation sources 31a may be directly installed at positions of two or more radiation sources. The radiation source 31a may be a point source, and it may be considered to shield a portion of the radiation from the point source that does not penetrate the inspected object 10. In an embodiment in which two or more radiation sources are positioned at the edges of the inspected object 10, among the radiations from the point source, the radiation that does not penetrate the inspected object 10 does not form projection data, and the projection data detection unit This is because 90 is detected as a kind of noise. However, it is considered that such a phenomenon can be minimized through post-processing such as noise removal on the obtained projection data set.

Considering that the invention relates to the oblique type CT, the incident radiation may be considered to be incident at an inclined angle with respect to the installation surface (the stage 20 surface) of the inspected object 10, but is not essential. That is, in an embodiment in which the radiation source (radiation station) is installed to be close to the non-test object (stage 20), and furthermore, is installed to be located at the edge of the inspected area, as a result, the incident radiation is inclined to the inspected area. This is because it is incident at a true angle.

Referring to FIG. 5, as another embodiment of the configuration of the incident radiation forming unit 30, the incident radiation forming unit 30 may be controlled by adjusting the radiation source 31 and the radiation flux from the radiation source unit 31. It may be to include a radiation flux control unit for forming the incident radiation incident on the test subject 10.

The radiation flux control unit 32 is a radiation shielding material 33, has an opening 34, and the radiation passing through the opening 34 can function as the incident radiation. For this embodiment, the opening 34 will be a radiation source, and it can be seen that incident radiation is emitted from the opening 34 as the radiation source. In particular, in the present invention, considering that the radiation source (spinning station) is located at two or more places, it will be reasonable that the opening 34 is also formed at two or more places. Radiation (incident radiation) passing through the opening 34 will function as a kind of point source, but it does not exclude that a line source or a partial region performs a function such as a shielded point source or line source.

The radiation source portion 31 may be a single radiation source 31a, but does not exclude the application of two or more radiation sources 31a.

The projection data detection unit 90 is provided on the opposite side of the radiation generating unit on the basis of the position of the inspected object 10, and acquires a projection data set generated by transmitting the incident radiation through the inspected object 10. Perform the function.

The projection data detection unit 90 may be shaped to cover the upper portion of the inspected object 10. In a typical CT apparatus, since the radiation source 31a and the detector are configured to rotate (or revolve together) relatively, it is sufficient that the detector also has a width sufficient to detect radiation from the radiation source 31a. However, since the projection data detection unit 90 of the present invention should acquire a projection data set which is located on the upper part of the inspected object 10 and is temporarily formed over a wide range, the radiation can be detected over a relatively large area. Its shape and installation location should be determined.

The three-dimensional image processing unit performs the function of restoring the three-dimensional internal shape image of the detection object by processing the projection data set, and of course, it can be configured by adopting a known configuration.

Since the function of the three-dimensional image processing unit is related to the method of restoring the three-dimensional internal shape image of the inspected object 10 using the non-rotational oblique type CT apparatus of the present invention, The description will be replaced by a method of restoring a three-dimensional internal shape image of the inspected object 10 using a non-rotating oblique type CT device.

With reference to FIG. 6, the method of restoring the 3D internal shape image of the to-be-tested object 10 using the non-rotational oblique type CT apparatus of this invention is demonstrated.

First, the test subject 10 is mounted on the stage 20.

Second, the incident radiation forming unit 30 forms the incident radiation. Incident radiation is emitted from a radiation source.

Third, incident radiation penetrates the object 10 and the projection data detection unit 90 acquires the single whole projection data 70 detected. This single whole projection data 70 is acquired at a time.

Fourthly, the three-dimensional image processing unit processes a single whole projection data 70 to restore the three-dimensional internal shape image of the inspected region. The method of restoring the 3D internal shape image using the plurality of projection data may be performed by applying a known technique such as a reverse projection algorithm. Hereinafter, the fourth step will be described in detail.

The three-dimensional image processing unit divides the single whole projection data 70 detected at one time to generate a plurality of projection data. In this regard, it has been described above.

Optionally, after storing the plurality of projection images subjected to the extraction process in the memory, the process may be performed later. Furthermore, in the step of storing in the memory, a plurality of projection data can be stored at the same time, which is possible because a plurality of projection images can be generated at the same time.

Thereafter, the 3D image processor performs filtering on each of the plurality of projection data. The filtering has a purpose to increase the resolution in synthesizing tomographic images, and a known technique can be applied.

Then, the geometric transformation and the rotation angle transformation are performed on each of the filtered plurality of projection data. This is a necessary step because the present invention relates to an oblique type CT apparatus, since each of the plurality of projection data is not based on the same rotation axis. Known techniques can be applied. At this time, each step of the geometric transformation and the rotation angle transformation is processed in parallel for each of the plurality of projection data, so that the processing speed can be increased. Furthermore, such parallel processing can simultaneously process each of the plurality of projection data, thereby making the processing speed even higher.

Although the present invention has been described with reference to the accompanying drawings, it is merely one example of various embodiments including the gist of the present invention, which can be easily implemented by those skilled in the art. It is clear that the present invention is not limited to the above-described embodiment only. Therefore, the protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent to the change, substitution, substitution, etc. within the scope not departing from the gist of the present invention shall be the right of the present invention. It will be included in the scope. In addition, some of the components of the drawings are intended to more clearly describe the configuration, and it is clear that the exaggerated or reduced size is provided.

[Description of the code]

10: subject

20: stage

30: incident radiation forming unit

31: radiation source unit

31a: radiation source

32: radiation flux control unit

33: radiation shielding material

34: opening

Radiation source

41: first station

42: second station

50: incident radiation

50a: first incident radiation

50b: second incident radiation

SUBk: Subincident Radiation

θk (k is a natural number): Incident angle of the subincident radiation (SUBk) on the subject

πk (k is a natural number): Radiation width angle of subincident radiation (SUBk)

60: Subject penetration area for subincident radiation

Pk (k is a natural number): Subject area for subincident radiation (SUBk)

61: first overlapping area

62: second overlapping area

70: single whole projection data

Sk to Ek (k is a natural number): Subprojection data (for k subincident radiation (SUBk))

90: projection data detection unit

M: Memory section

F: filtering unit

G: geometric transformation

R: rotation angle converter

Claims

In the oblique type CT device for restoring a three-dimensional internal shape image of a region to be inspected,

A stage in which the inspected object is located;

An incident radiation forming unit for forming an incident radiation to be irradiated on the inspected object;

A projection data detection unit provided on the opposite side of the incident radiation generating unit based on the position of the inspected object and obtaining a projection data set generated by transmitting the incident radiation through the inspected object; And

A three-dimensional image processing unit for processing the projection data set to restore a three-dimensional internal shape image of the inspected region;

Including,

The incident radiation is formed as a pattern radiating from a radiation source proximate to the object to be inspected and located at a point spaced outwardly from a central position of the region to be inspected,

And the projection data set is acquired at a time.
The method according to claim 1,

The projection data set is a set of a plurality of projection data obtained by dividing a single whole projection data detected at a time on the projection data detection unit,

And each of the plurality of projection data reflects an angle of incidence of each of the inspected regions of each of the plurality of sub-incidence radiations in which the incidence radiation is virtually divided and set.
The method according to claim 2,

The radiation source is a non-rotating oblique type CT device, characterized in that two or more radiation sources.
The method according to claim 3,

The radiation source consists of two radioactive sources (the first and the second).

The incident radiation is a first incident radiation and a second incident radiation corresponding to each of the first radiation station and the second radiation station,

The non-rotating oblique type CT device is characterized in that the plurality of sub-incident radiation is a first sub-radiation radiation set and a second sub-radiation radiation set corresponding to each of the first incident radiation and the second incident radiation. .
The method according to claim 1,

The incident radiation forming unit,

Radiation source section, and

A radiation flux control unit for controlling the radiation flux from the radiation source unit to form the incident radiation incident on the object under test;

Non-rotating oblique type CT device comprising a.
The method according to claim 5,

The non-rotating oblique type CT device, wherein the radiation flux adjusting portion is a radiation shielding material, has an opening, and the radiation passing through the opening functions as the incident radiation.
The method according to claim 6,

The radiation source portion, non-rotating oblique type CT device, characterized in that it comprises a single radiation source.
The method according to claim 1,

And the projection data detection unit is shaped to cover an upper portion of the inspected object.
In the method for setting the inspection target area of the non-rotating oblique type CT apparatus of claim 2,

(1) dividing the incident radiation, setting the plurality of subincident radiations, and receiving each of the plurality of subincident radiations, the incidence angle of the object under test;

(2) measuring the subject penetration region for each of the plurality of subincident radiations;

(3) determining an area (overlapping area) in which each of the inspected object transmissive areas for each of the plurality of sub-incident radiations overlaps;

(4) determining the overlapped area as the inspected area;

Method of setting the inspection target area of the non-rotating oblique type CT device comprising a.
In a method for obtaining a plurality of projection data for a region to be inspected from a single total projection data for a non-rotational oblique type CT device is determined by the method of claim 9,

(a) dividing the single whole projection data to derive subprojection data corresponding to each of the plurality of subincident radiations;

(b) extracting portions of the sub-projection data for each of the plurality of sub-incident radiations that are actually transmitted and detected in the inspected region;

(c) designating the portions extracted in the step (b) as the plurality of projection data of the inspected region;

Method of obtaining a plurality of projection data for the inspected area including a.
In the method for setting the inspection target area of the non-rotating oblique type CT apparatus of claim 4,

(1) A plurality of sub-incidences which divide the first incident radiation and the second incident radiation, set the first subincident radiation set and the second subincident radiation set, and constitute the first subincident radiation set. Receiving each of a plurality of sub-incident radiations constituting the radiation and the second sub-incident radiation set, the angle of incidence of the object to be examined;

(2) measuring the inspected object penetrating area for each of the plurality of sub-incident radiations constituting the first sub-incident radiation set and each of the plurality of sub-incident radiations constituting the second sub-incident radiation set;

(3) A region (first overlapping region) in which each of the inspected subject transmission regions for each of the plurality of sub-incident radiations constituting the first sub-incident radiation set is overlapped is determined to form the second sub-incident radiation set. Determining an area (second overlapping area) in which each of the inspected object transmissive areas for each of a plurality of sub-incident radiations overlaps;

(4) determining an overlapping area between the first overlapping area and the second overlapping area as the inspected area;

Method of setting the inspection target area of the non-rotating oblique type CT device comprising a.
The method according to claim 11,

And the first overlapping area and the second overlapping area are set to be the same.
In the method of restoring the three-dimensional internal shape image of the subject under the non-rotating oblique type CT device of claim 2,

(i) placing the subject under test on the stage;

(ii) the incident radiation forming unit forming the incident radiation, and the incident radiation passing through the test object;

(iii) the projection data detection unit detecting the single whole projection data at once; And

(iv) the three-dimensional image processing unit processing the single whole projection data to restore a three-dimensional internal shape image of the inspected region;

3D internal shape image restoration method of the subject using a non-rotating oblique type CT device comprising a.
The method according to claim 13,

Step (iv),

(iv-1) generating the plurality of projection data by processing the single whole projection data by the three-dimensional image processing unit;

(iv-2) performing filtering on each of the plurality of pieces of projection data by the 3D image processing unit;

(iv-3) performing, by the three-dimensional image processing unit, geometric transformation on each of the filtered plurality of projection data, and

(iv-4) performing, by the three-dimensional image processing unit, rotation angle transformation on each of the plurality of pieces of projection data on which the geometric transformation has been performed;

Including,

The method after the step (iv-3) is performed in parallel with each of the plurality of pieces of projection data, wherein the three-dimensional internal shape image restoration method of the inspected object using a non-rotating oblique type CT device.
The method according to claim 13,

Between step (iv-1) and step (iv-2),

And storing each of the plurality of projection data in a memory, wherein the three-dimensional internal shape image restoration method of the inspected object using a non-rotating oblique type CT device.