KR20240053755A - Dual-energy based tomosynthesis system - Google Patents

Abstract

Embodiments of the present invention include an X-ray generator that irradiates high-energy X-rays and low-energy X-rays to a subject to be photographed; an X-ray detector for generating a plurality of high-energy images and a plurality of low-energy images by detecting high-energy X-rays and low-energy a motion control unit that moves at least one of the X-ray generator and the and an X-ray level control unit that controls the X-ray generator to irradiate high-energy A dual energy-based tomosynthesis device can be provided.
According to embodiments of the present invention, the radiation exposure can be reduced by acquiring low-energy and high-energy tomosynthesis images with a small number of Since diagnostic images with highlighted areas can be provided, diagnostic capabilities can be improved.

Description

Dual energy based tomosynthesis device {DUAL-ENERGY BASED TOMOSYNTHESIS SYSTEM}

The present invention relates to a tomosynthesis device, and more specifically, to a dual energy-based tomosynthesis device that can reduce radiation exposure and improve diagnostic ability by acquiring low-energy and high-energy tomosynthesis images with a small number of X-ray irradiations and a small amount of X-ray irradiation. It's about.

Currently, in chest and breast diagnosis, devices are used that display 3D images and tomographic images using mathematical algorithms using 2D images taken multiple times from various angles.

CT (Computed Tomography) uses an algorithm to reconstruct hundreds of projection data of the target object obtained by rotating 360 degrees along a circular orbit by pairing an X-ray generator and an X-ray detector with the target object to be imaged as the center of rotation. It shows many depth information-based tomographic images.

However, CT not only requires a large space, is expensive, and takes a long time for imaging, but also has the disadvantage of poor image quality due to the large amount of X-ray radiation, high exposure to the subject being photographed, and the large pixel size of the X-ray detector.

A digital tomography device, or tomosynthesis, is a device in which an X-ray generator and an Using dozens of projection data acquired while moving, a cross-sectional image of the subject is reconstructed to provide a diagnostic image.

Tomosynthesis has the advantage of being able to accurately and precisely check patient conditions, diseases, lesions, etc. by checking tomography (slice) images in the depth direction of the human body, in addition to having a small number of shots, short shooting time, and low radiation exposure to the subject. .

Meanwhile, the energy level of X-rays for obtaining the desired diagnostic image varies depending on body tissue. For example, a low energy level is suitable for obtaining diagnostic images of soft tissues such as skin, and a high energy level is suitable for obtaining diagnostic images of hard tissues such as bones or teeth.

However, double imaging from multiple angles with a low energy level and a high energy level for each angle takes a long time and increases the exposure of the subject. Therefore, there is a need for a method that can reduce the amount of radiation exposure to the subject of imaging while obtaining high-quality diagnostic images.

Republic of Korea Patent Publication No. 10-2022-0129974 (published on September 29, 2022)

The present invention was created to solve the problems of the prior art as described above, and is a dual energy-based TOMO that can reduce radiation exposure and improve diagnostic ability by shooting low-energy images and high-energy images with a small number of X-ray irradiations and a small amount of X-ray irradiation. The purpose is to provide a synthesis device.

In addition, the detailed purpose of the present invention can be clearly understood and understood by experts or researchers in this technical field through the specific contents described below.

A dual energy-based tomosynthesis device according to embodiments of the present invention includes an X-ray generator that irradiates high-energy X-rays and low-energy X-rays to a subject to be photographed; an X-ray detector for generating a plurality of high-energy images and a plurality of low-energy images by detecting high-energy X-rays and low-energy a motion control unit that moves at least one of the X-ray generator and the and an X-ray level control unit that controls the X-ray generator to irradiate high-energy can do.

In the dual energy-based tomosynthesis device according to embodiments of the present invention, the X-ray level control unit controls the X-ray generator to alternately radiate high-energy X-rays and low-energy X-rays while traveling through the imaging range once. do.

In the dual energy-based tomosynthesis device according to embodiments of the present invention, the X-ray level control unit controls the X-ray generator to irradiate only one of high-energy X-rays and low-energy .

In the dual energy-based tomosynthesis device according to embodiments of the present invention, the X-ray detector includes a low-energy detection unit and a high-energy detection unit overlapping with each other.

In the dual energy-based tomosynthesis device according to embodiments of the present invention, the low-energy detection unit is disposed ahead of the high-energy detection unit in the direction of X-ray travel.

In the dual energy-based tomosynthesis device according to embodiments of the present invention, the X-ray level control unit controls the X-ray generator so that the irradiation amount of low-energy X-rays is smaller than the irradiation amount of high-energy X-rays.

In the dual energy-based tomosynthesis device according to embodiments of the present invention, the high-energy detection unit and the low-energy detection unit each absorb X-rays and convert the visible light generated from the scintillator layer into an electrical signal. It includes an image sensor layer that converts, and the low-energy detection unit is configured such that the scintillator layer is disposed in front of the image sensor layer in the X-ray direction, and the high-energy detection unit is configured to have the image sensor layer in front of the scintillator layer in the X-ray direction. It is characterized by being configured as possible.

According to one embodiment of the present invention, low-energy and high-energy tomosynthesis images are obtained with a small number of X-ray irradiations and a small amount of Therefore, the amount of radiation exposure can be reduced and diagnostic ability can be improved.

The accompanying drawings, which are included as part of the detailed description to aid understanding of the present invention, provide examples of the present invention and explain the technical idea of the present invention along with the detailed description.
1 is a schematic diagram of a dual energy-based tomosynthesis device according to an embodiment of the present invention.
Figure 2 is a diagram showing an example of an X-ray irradiation method of a dual energy-based tomosynthesis device according to an embodiment of the present invention.
3A and 3B are diagrams showing another example of an X-ray irradiation method of a dual energy-based tomosynthesis device according to an embodiment of the present invention.
Figure 4a is a cross-sectional view showing an example of an X-ray detector of a dual energy-based tomosynthesis device according to the present invention.
Figure 4b is a cross-sectional view showing another example of the X-ray detector of the dual energy-based tomosynthesis device according to the present invention.
Figure 5 is a diagram showing a method of implementing a diagnostic image using a dual energy-based tomosynthesis device according to an embodiment of the present invention.

The present invention can be modified in various ways and can have various embodiments. Hereinafter, specific embodiments will be described in detail based on the accompanying drawings.

The following examples are provided to provide a comprehensive understanding of the methods, devices and/or systems described herein. However, this is only an example and the present invention is not limited thereto.

In describing the embodiments of the present invention, if it is determined that a detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. In addition, the terms described below are terms defined in consideration of functions in the present invention, and may vary depending on the intention or custom of the user or operator. Therefore, the definition should be made based on the contents throughout this specification. The terminology used in the detailed description is only for describing embodiments of the present invention and should in no way be limiting. Unless explicitly stated otherwise, singular forms include plural meanings. In this description, expressions such as “comprising” or “including” are intended to indicate certain features, numbers, steps, operations, elements, parts or combinations thereof, and one or more than those described. It should not be construed to exclude the existence or possibility of any other characteristic, number, step, operation, element, or part or combination thereof.

In addition, terms such as first, second, etc. may be used to describe various components, but the components are not limited by the terms, and the terms are used for the purpose of distinguishing one component from another component. It is used only as

1 is a schematic diagram of a dual energy-based tomosynthesis device according to an embodiment of the present invention.

Referring to FIG. 1, the dual energy-based tomosynthesis device according to an embodiment of the present invention includes an X-ray generator 10 that irradiates high-energy X-rays and low-energy an X-ray detector 20 that detects and generates a plurality of high-energy images and a plurality of low-energy images, and at least one of the X-ray generator 10 and the A motion control unit 30 that moves within the imaging range, an X-ray generator to irradiate high-energy It may include an X-ray level control unit 40 that controls (10). In addition, the dual energy-based tomosynthesis device according to an embodiment of the present invention may further include an image reconstruction unit 60.

The X-ray generator 10 may generate high-energy band X-rays (high-energy X-rays) and low-energy band X-rays (low-energy X-rays), and may generate high-energy X-rays and One of the low-energy X-rays can be irradiated.

The X-ray generator 10 may adjust the dose of low-energy X-rays and high-energy X-rays in response to the second control signal from the X-ray level controller 40.

The dose of high-energy X-rays and the dose of low-energy X-rays irradiated from the X-ray generator 10 may be different from each other. By way of example, the dose of low-energy X-rays may be less than that of high-energy X-rays, but is not limited thereto. The dose of low-energy X-rays and the dose of high-energy X-rays can be appropriately adjusted depending on the structure of the X-ray detector 20.

The X-ray generator 10 is mounted on an arm 50 that moves and rotates by driving a motor, and can rotate and move at various imaging angles around the X-ray detector 20.

Although this embodiment shows a case where the X-ray generator 10 is a rotating type and the X-ray detector 20 is a non-rotating type, the present embodiment is not limited to this. Unlike this embodiment, the X-ray generator 10 may be configured as a non-rotating type and the X-ray detector 20 may be configured as a rotating type, or both the X-ray generator 10 and the X-ray detector 20 may be configured as a rotating type. You may. If the X-ray generator 10 and the X-ray detector 20 have a structure in which the X-ray generator 10 and the X-ray detector 20 rotate relatively so that imaging can be performed at various angles, they can all be included in the scope of the present invention.

The X-ray detector 20 has a structure in which a low-energy detection unit for detecting low-energy X-rays and a high-energy detection unit for detecting high-energy All can be detected. Optionally, the height of the X-ray detector 20 may be adjustable depending on the location of the object to be photographed.

The motion control unit 30 may rotate and move at least one of the X-ray generator 10 and the X-ray detector 20 so that imaging is performed at various angles (A1 to A5). As an example, the motion control unit 30 may control the driving of a motor that rotates the arm 50 on which the X-ray generator 10 is mounted. The motor is driven under the control of the motion control unit 30, and as the arm 50 moves due to the driving of the motor, the X-ray generator 10 may rotate around the X-ray detector 20.

The X-ray level control unit 40 irradiates low-energy The X-ray generator 10 can be controlled as much as possible.

The X-ray level control unit 40 may control the X-ray generator 10 so that the dose of high-energy X-rays and the dose of low-energy X-rays irradiated by the X-ray generator 10 have different sizes. As an example, the X-ray level control unit 400 may control the X-ray generator 10 so that the low-energy X-ray irradiation amount is smaller than the high-energy X-ray irradiation amount.

The image reconstruction unit 60 may reconstruct images captured at multiple first angles to generate a low-energy tomosynthesis image, and may reconstruct images captured at multiple second angles to generate a high-energy tomosynthesis image.

The image reconstruction unit 60 designs the relationship between the high-energy image and the low-energy image using an artificial neural network using the previously implemented high-energy image and the low-energy image, and uses the designed artificial neural network to design the low-energy image captured from the first angle. A high-energy image may be obtained from , and a low-energy image may be obtained from the high-energy image taken from a second angle.

In this case, the image reconstruction unit 60 uses high-energy images taken at multiple second angles to reconstruct low-energy images obtained through an artificial neural network and low-energy images taken at multiple first angles to create a low-energy tomosynthesis image. can be created. In addition, a high-energy tomosynthesis image can be generated by reconstructing a high-energy image obtained through an artificial neural network and a high-energy image taken from a plurality of second angles using low-energy images taken from a plurality of first angles.

Additionally, the image reconstruction unit 60 may implement a difference image between a low-energy tomosynthesis image and a high-energy tomosynthesis image. At this time, a weight may be applied to at least one of the high-energy tomosynthesis image and the low-energy tomosynthesis image. The weights needed to acquire an image emphasizing soft tissue and the weights needed to obtain an image emphasizing hard tissue are different, and must be obtained separately depending on the purpose, but the method for obtaining the weights may be the same.

Figure 2 is a diagram showing an example of an X-ray irradiation method of a dual energy-based tomosynthesis device according to an embodiment of the present invention, and Figures 3A and 3B are diagrams showing an example of an These are drawings showing different examples of X-ray irradiation methods.

As shown in FIG. 2, the X-ray level control unit 40 may control the X-ray generator 10 to alternately irradiate low-energy X-rays and high-energy X-rays while traveling through the imaging range once. The X-ray generator 10 radiates low-energy X-rays from a plurality of first angles (A1, A3, A5) while traveling through the imaging range once, and generates a plurality of High-energy X-rays can be irradiated from the second angle (A2, A4).

Meanwhile, as shown in FIGS. 3A and 3B, the X-ray level controller 40 may control the X-ray generator 10 to irradiate only one of low-energy X-rays and high-energy X-rays while traveling through the imaging range once. During the first run, the X-ray generator 10 may radiate low-energy Also, during the second run, the X-ray generator 10 may irradiate high-energy

FIG. 4A is a cross-sectional view showing an example of an X-ray detector of a dual energy-based tomosynthesis device according to the present invention, and FIG. 4B is a cross-sectional view showing another example of an X-ray detector of a dual energy-based tomosynthesis device according to the present invention.

Referring to FIG. 4A, the X-ray detector 20 of the dual energy-based tomosynthesis device according to the present invention may include a low-energy detection unit 100 and a high-energy detection unit 200 that overlap each other along the X-ray direction.

Illustratively, the low-energy detection unit 100 may be placed in front of the high-energy detection unit 200 in the X-ray traveling direction. In this case, the X-rays incident on the Accordingly, the amount of X-ray radiation required for detection in the high-energy detection unit 200 is greater than the amount of X-ray radiation required for detection in the low-energy detection unit 100.

In the present disclosure, since low-energy X-rays and high-energy X-rays are detected separately, the X-ray radiation dose for low-energy

The low-energy detection unit 100 includes a first scintillator layer 110 that absorbs low-energy X-rays and generates visible light, and a first image sensor layer that converts the visible light generated by the first scintillator layer 110 into an electrical signal and outputs it. It is composed including (120).

The high-energy detection unit 200 includes a second scintillator layer 210 that generates visible light by absorbing high-energy It is configured to include a second image sensor layer 220 that converts and outputs an electrical signal. The second scintillator layer 210 has a greater thickness than the first scintillator layer 110.

The low energy detection unit 100 may have a front incident structure. That is, the first scintillator layer 110 of the low energy detection unit 100 may be disposed at the front of the first image sensor layer 120 in the X-ray traveling direction.

The first scintillator layer 110, which is thin and has few sites that generate visible light, is placed on the side where X-rays are incident, allowing the first scintillator layer 110 to absorb a larger amount of X-rays, thereby allowing the first scintillator layer 110 to absorb a larger amount of The amount of light generated from the scintillator layer 110 can be increased.

The high energy detection unit 200 may also have a front incident structure. That is, the second scintillator layer 210 of the high energy detection unit 200 may be disposed at the front of the second image sensor layer 220 in the X-ray traveling direction.

Meanwhile, as shown in FIG. 4B, the high energy detection unit 200 may have a rear incident structure. That is, the second scintillator layer 210 of the high energy detection unit 200 may be disposed behind the second image sensor layer 220 in the X-ray traveling direction.

X-rays incident on the high-energy detection unit 200 pass through the second image sensor layer 220 and are transmitted to the second scintillator layer 210, and most of the X-rays transmitted to the second scintillator layer 210 are transmitted to the second image sensor layer. It is absorbed into the second scintillator layer 210 near (220). Accordingly, a large amount of visible light is generated near the second image sensor layer 220 and the amount of light collected by the second image sensor layer 220 increases, so the second image sensor layer 220 can form a large image signal. You can. In addition, spatial resolution is also improved because visible light travels a short distance and scattering is reduced.

As described above, X-rays pass through the low-energy detection unit 100 and enter the high-energy detection unit 200 with a reduced amount of X-rays. If the high-energy detection unit 200 is configured with a rear incident structure, it is possible to obtain a sufficient detection effect by maximally absorbing X-rays with a reduced dose and reduce the amount of radiation exposure to the subject of imaging.

In the above, the case where the low-energy detection unit 100 is disposed in front of the high-energy detection unit 200 in the X-ray direction has been described, but the scope of the present invention is not limited to this. Conversely, the high-energy detection unit 200 may be placed in front of the low-energy detection unit 100 in the X-ray direction, and various dual-energy image qualities can be realized depending on the arrangement order.

The first and second scintillator layers 110 and 210 may be composed of a multi-layer scintillator that emits light at various wavelengths. Scintilents that emit light at various wavelengths include Gd ₂ O ₂ S:Eu, Gd ₂ O ₃ :Eu, Y ₂ O ₂ S:Eu, (Y,Gd) ₂ O ₃ :Eu, which emit red. , Gd ₂ O ₂ S:Tb, CsI:Tl, which is a scintillator that emits green light, and CaWO ₄ , a scintillator that emits blue light, BaFBr:Eu+CaWO ₄ , etc. Depending on the application field or to improve image quality, the type of scintillator material applied to the first and second scintillator layers 110 and 210 may be appropriately selected.

Meanwhile, one of the first and second scintillator layers 110 and 210 may have a double-layer structure with different scintillator particle scales. In this case, of the two layers included in each scintillator layer, the layer with a larger particle scale may be arranged on the image sensor layer.

As the particle scale increases, the amount of visible light generated from the scintillator particles increases. A layer with a large particle scale is placed on the image sensor layer to generate a large amount of visible light near the image sensor layer, thereby increasing the amount of light collected in the image sensor layer, so the image sensor layer can form a large image signal. In addition, spatial resolution is also improved because visible light travels a short distance and scattering is reduced.

The first and second image sensor layers 120 and 220 include a plurality of pixels arranged one-dimensionally or two-dimensionally on a substrate, and photodiodes formed in a one-dimensional or two-dimensional array to correspond to the plurality of pixels. It may include a circuit array for driving pixels.

In order to minimize the amount of X-rays absorbed by the first and second image sensor layers 120 and 220, a thin glass substrate or a plastic substrate may be used as a substrate for the first and second image sensor layers 120 and 220. An amorphous silicon photodiode that selectively absorbs the visible light spectrum can be used as the photodiode, and amorphous silicon and oxide-based TFT panel methods can be used as the circuit array.

Figure 5 is a diagram showing a method of implementing a diagnostic image using a dual energy-based tomosynthesis device according to an embodiment of the present invention.

Referring to FIG. 5, in order to implement a diagnostic image using a dual energy-based tomosynthesis device according to an embodiment of the present invention, an object to be imaged is first imaged with low-energy X-rays from a plurality of first angles, and a high-energy The subject is photographed with energy X-rays.

Next, the images taken at a plurality of first angles are reconstructed to generate a low-energy tomosynthesis image, and the images taken at a plurality of second angles are reconstructed to generate a high-energy tomosynthesis image.

Afterwards, a difference image is implemented between the low-energy tomosynthesis image and the high-energy tomosynthesis image. At this time, weighting may be applied to at least one of the high-energy tomosynthesis image and the low-energy tomosynthesis image to emphasize soft tissue or hard tissue.

Accordingly, diagnostic images that visually show various anatomical information, such as images in which only hard tissues are emphasized, images in which only soft tissues are emphasized, and images in which all tissues are overlapped, can be provided to the user.

As above, according to the embodiments of the present invention, the radiation exposure can be reduced by acquiring low-energy and high-energy tomosynthesis images with a small number of X-ray irradiation and a small amount of Diagnostic capabilities can be improved by providing diagnostic images with specific body parts highlighted.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications and variations will be possible to those skilled in the art without departing from the essential characteristics of the present invention. Accordingly, the embodiments described in the present invention are for illustrative purposes rather than limiting the technical idea of the present invention, and are not limited to these embodiments. The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of rights of the present invention.

10: X-ray generator
20: X-ray detector
30: motion control unit
40: X-ray level control unit
50: arm
60: Image reconstruction unit
100: low energy detection unit
200: High energy detection unit
110,210: 1st and 2nd scintillator layers
120,220: 1st and 2nd image sensor layers
310,320: 1st and 2nd X-ray filters

Claims (7)

An X-ray generator that irradiates high-energy X-rays and low-energy X-rays to an object to be photographed;
an X-ray detector for generating a plurality of high-energy images and a plurality of low-energy images by detecting high-energy X-rays and low-energy
a motion control unit that moves at least one of the X-ray generator and the and
an X-ray level control unit that controls the X-ray generator to radiate high-energy X-rays from a plurality of first angles among the plurality of angles and to irradiate low-energy
A dual energy-based tomosynthesis device comprising a.
The dual energy-based tomosynthesis device of claim 1, wherein the X-ray level control unit controls the X-ray generator to alternately irradiate high-energy X-rays and low-energy X-rays while traveling through the imaging range once.
According to paragraph 1,
The X-ray level control unit controls the X-ray generator to irradiate only one of high-energy X-rays and low-energy X-rays while traveling through the imaging range once.
According to paragraph 1,
The X-ray detector is a dual energy-based tomosynthesis device, characterized in that it includes a low-energy detection unit and a high-energy detection unit overlapping each other.
According to clause 4,
A dual energy-based tomosynthesis device, wherein the low-energy detection unit is disposed ahead of the high-energy detection unit in the direction of X-ray travel.
According to clause 5,
The X-ray level control unit is a dual energy-based tomosynthesis device, characterized in that the X-ray generator is controlled so that the irradiation amount of low-energy X-rays is smaller than the irradiation amount of high-energy X-rays.
According to clause 5,
The high-energy detection unit and the low-energy detection unit each include a scintillator layer that absorbs X-rays to generate visible light and an image sensor layer that converts the visible light generated by the scintillator layer into an electrical signal,
The low-energy detection unit is configured such that the scintillator layer is disposed in front of the image sensor layer in the X-ray direction,
The high-energy detection unit is a dual energy-based tomosynthesis device, characterized in that the image sensor layer is arranged in front of the scintillation layer in the X-ray direction.

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