Breast computed tomography apparatus

Abstract

The present invention relates to a breast computed tomography apparatus comprising a gantry capable of self-shielding and moving. The breast computed tomography apparatus, according to the present invention, generates ultralow-dose X-rays and is freely installed and moved by using self-X-ray shielding. In particular, the breast computed tomography apparatus enables examinations without physical and clinical limitations by using perfect three-dimensional images without pressing breasts and does not require additional examinations, such as MRI or ultrasound, and thus is comfortable and accurate and can be used for various clinical tests with minimal face-to-face visits and contact, and captured images can provide actual change information, thereby maximizing the usability of the breast computed tomography apparatus in conjunction with AI.

Description

Breast CT Scanner

[0001] The present invention relates to a breast tomography device, and more particularly, to a breast tomography device having a self-shielding and movable gantry.

[0002] Typically, mammography devices use X-rays to diagnose breast cancer early. That is, a certain amount of X-rays are passed through the breasts of the subject, and the transmitted X-rays can be converted into digital, two-dimensional images using photosensitive film or an electrical image sensor. Mammography devices have a structure in which a pressure member, which compresses the subject, including the breast, is positioned between the X-ray generator and the X-ray detector to improve image quality and reduce the required dose.

[0003] However, since the mammography device has a structure that applies compression to the breast using a pressurized member to reduce radiation exposure while improving image quality, the person being examined often feels pain in the breast area and the image often becomes distorted.

[0004] Additionally, there are many restrictions on taking pictures of breasts that have undergone plastic surgery, and there are side effects such as increased X-ray dose and rupture of the implant.

[0005] Additionally, there is concern that postoperative monitoring of lesions may be difficult because the breast cannot be compressed after breast surgery.

[0006] In particular, conventional technologies have fundamentally inadequate performance and functions, such as difficulty in accurately measuring the volume of lesions, making it difficult to monitor neoadjuvant chemotherapy, which requires accurate measurement of volume changes, and difficulty in determining the extent of disease (EOD) (breast imaging-reporting and data system, BIRADS), as well as having to diagnose a three-dimensional specimen by viewing it in two dimensions.

[0007] In addition, dense breasts, where the lower structures are not visible because they are covered by the upper structures, have the inconvenience of a higher probability of false negatives and false positives.

[0008] In contrast, breast computed tomography (BCT) is designed to eliminate breast compression, eliminating side effects like pain and allowing for comfortable examinations regardless of surgery or plastic surgery. Its complete three-dimensional view allows for accurate examinations regardless of breast density. Furthermore, BCT facilitates postoperative monitoring and neoadjuvant chemotherapy monitoring, and facilitates determination of the extent of disease (BIRADS).

[0009] Additionally, BCT has the advantage of having no clinical limitations due to its own physical characteristics (for example, ultrasound or magnetic resonance imaging (MRI) have difficulty detecting microcalcifications, which are indicators of early breast cancer), and minimizing face-to-face and contact by not requiring supplementary examination of dense breasts.

[0010] In BCT, positioning is based solely on gravity, and observation is easy up to the lymph nodes without any limitations on the diagnostic area from the nipple to the chest wall, making it easy to check for metastasis.

[0011] In particular, BCT has the advantage of being able to easily utilize a permanent and perfect artificial intelligence platform (AI Platform) without clinical or physical limitations for AI diagnosis, which is expected to be applied to all diagnoses in the future.

[0012] However, even with the above-mentioned advantages, BCT currently requires a higher X-ray dose than mammography devices, and has the inconvenience of having to shield all six sides of the facility. That is, in general, the boundaries between floors in a room with a BCT are constructed with thick concrete, so that the upper and lower floors sometimes omit shielding, and the four sides of the room on the front, back, left, and right are shielded, and in some cases, all six sides including the top and bottom are shielded. Therefore, conventional BCTs must be installed only in shielded rooms, and their installation area and shielding issues are not easy, so space utilization is limited, and it is difficult to avoid excessive installation time, installation cost, excessive radiation exposure, and environmental pollution.

[0013] In addition, BCT can be used very usefully in radiology departments, screening centers, breast surgery departments, cancer centers, and operating rooms compared to mammography devices, but mobility is required when necessary, and BCT with a fixed structure is inconvenient to move and it is not easy to reduce space utilization and installation costs.

[0014] The purpose of the present invention is to provide a breast tomography device that has many advantages in breast diagnosis, can be miniaturized, generates a small amount of X-rays, and completely shields X-rays to prevent leakage of X-rays to the outside.

[0015] The purpose of the present invention is to provide a breast tomography device that can be freely installed and moved and maximizes space utilization.

[0016] The present invention aims to provide a breast tomography device that can reduce energy consumption and increase economic efficiency by being lightweight and miniaturized.

[0017] The purpose of the present invention is to provide a breast tomography device that can quickly process signals from captured images to obtain rapid results.

[0018] The present invention is not limited to the above-mentioned purposes, and other purposes and advantages of the present invention that are not mentioned can be understood by the following description, and will be more clearly understood by the embodiments of the present invention.

[0019] According to one embodiment of the present invention, there is provided an apparatus comprising: a frame having a box shape with a space formed therein; a rotating gear rotatably coupled to the interior of the frame; an X-ray tube coupled to one side of the rotating gear and configured to generate X-rays; an X-ray detector coupled to the other side of the rotating gear and configured to rotate about a rotational center axis and be driven to move back and forth with respect to a subject, the detector receiving X-rays generated from the X-ray tube and passing through the subject and converting the X-rays into electrical signals; a shielding unit formed over the entire inner surface of the frame except for an opening in one side of the frame through which the subject is inserted, the shielding unit preventing X-rays generated from the X-ray tube from leaking out of the frame; an image reconstruction unit reconstructing an image formed by a signal converted by the X-ray detector; and an image display unit displaying the image reconstructed by the image reconstruction unit, wherein the image reconstruction unit calculates a change in pixel value by digitally subtracting a same pixel between the two images by shifting a previous image of the photographing date by a pixel of the photographing date, and reconstructs an image in which the calculated change is reflected for each pixel.

[0020] In the present invention, the image reconstruction unit groups voxels, which are 3D pixels, in the image, shifts the central voxel of the image formed by the voxel group to a voxel having a voxel value of 0 in the image, calculates a change in the voxel value through the digital subtraction, and then reconstructs an image in which the calculated change is reflected for each voxel.

[0021] In the present invention, the shielding member is composed of a lead plate.

[0022] In the present invention, the test subject includes a breast.

[0023] In the present invention, the frame is configured to be tiltable relative to a horizontal plane and to maintain the subject positioned in the opening in a state in which it faces downward due to its own weight.

[0024] In the present invention, a moving means including wheels on the lower side of the frame is included to enable the frame to move.

[0025] A breast computed tomography (BCT) device according to an embodiment of the present invention has the following effects.

[0026] According to the present invention, by comparing the pixel values ​​of an image captured by a breast tomography device with respect to two images taken on the same day and before the same day, and deriving the difference, an accurate examination result can be derived.

[0027] According to the present invention, in the process of comparing two images taken on the same day and before the same day, a quick inspection is possible by moving pixels or comparing pixel bundles of multiple pixels to each other to derive the difference in pixel values ​​of each bundle.

[0028] Figure 1 is a conceptual diagram of a breast tomography device according to an embodiment of the present invention.

[0029] Figure 2 is a configuration diagram of an X-ray detector constituting a breast tomography device according to an embodiment of the present invention.

[0030] Figure 3 is a schematic perspective view illustrating a breast tomography device according to an embodiment of the present invention.

[0031] Figure 4 is a configuration diagram of a support for supporting a breast tomography device according to an embodiment of the present invention.

[0032] FIGS. 5 to 7 are conceptual diagrams for explaining a process of finding out pixel values ​​of an image captured by a breast tomography device according to an embodiment of the present invention.

[0033] A breast tomography device (100) according to an embodiment of the present invention will be described in detail below with reference to FIGS. 1 to 6.

[0034] FIG. 1 is a conceptual diagram of a breast tomography device according to an embodiment of the present invention, FIG. 2 is a diagram of an X-ray detector constituting a breast tomography device according to an embodiment of the present invention, FIG. 3 is a schematic perspective view for explaining a breast tomography device according to an embodiment of the present invention, FIG. 4 is a diagram of a configuration of a support for supporting a breast tomography device according to an embodiment of the present invention, and FIGS. 5 to 7 are conceptual diagrams for explaining a process of finding out pixel values ​​of an image captured by a breast tomography device according to an embodiment of the present invention.

[0035] As illustrated in FIGS. 1 to 4, a breast tomography device (100) according to an embodiment of the present invention includes a gantry (200). The gantry (200) includes a frame (210) having a space formed therein, a rotary gear (220) rotatably coupled to the interior of the frame (210), an X-ray tube (230) coupled to one side of the rotary gear (220) to generate X-rays by an applied high voltage, an X-ray detector (240) coupled to the other side of the rotary gear (220) to receive X-rays generated from the X-ray tube (230) and passing through a subject and convert them into electrical signals, and a data collection unit (610) that stores data according to the electrical signals converted by the X-ray detector (240).

[0036] In addition, the breast tomography device (100) according to an embodiment of the present invention may include a configuration that supplies power to the gantry (200) in conjunction with the gantry (200) and processes images captured by the gantry (200). Specifically, this configuration may include an operation console (510) provided to enable an operator to input, a control unit (500) that controls an X-ray tube (230), an X-ray detector (240), and a data collection unit (610), an image display unit (620) that displays an image, an X-ray power supply unit (630) that generates a high voltage under the control of the control unit (500) and supplies it to the X-ray tube (230), and an image reconstruction unit (640) that calculates pixel values ​​of an image formed by data from the data collection unit (610) and transmits the calculated pixel values ​​to the image display unit (620).

[0037] In addition, the breast tomography device (100) according to an embodiment of the present invention may further include a supporter (300) and a moving means (400).

[0038] As shown in FIGS. 2 and 4, the gantry (200) includes a frame (210) to which an X-ray tube (230) and an X-ray detector (240) for acquiring medical images can be coupled, and the frame (210) can be adjusted in height or tilted at an angle by a tilting means (310) of a supporter (300).

[0039] Although the drawing and the above description describe that the X-ray tube (230), the X-ray detector (240), and the data collection unit (610) are arranged inside the frame (210) of the gantry (200), in another embodiment, at least one of the control unit (500) including the operation console (510), the image reconstruction unit (640), and the image display unit (620) may be installed in the gantry (200).

[0040] The rotary gear (220) is provided in a circular plate shape, and an X-ray tube (230), an X-ray detector (240), and the rotary gear (220) can be combined. The rotary gear (220) is provided in a circular plate shape and can rotate around a rotational center axis (see 'CL' in FIG. 2), and the rotational speed can be controlled by a motor (not shown) according to the control of the control unit (500).

[0041] A gantry (200) having a roughly square box shape is provided with an opening (213) into which the breast, which is the subject of the examination, can be inserted, and also has a sunken portion (215) so that the subject's arms, legs, etc. can be inserted.

[0042] The entire inner surface of the gantry (200) (more specifically, the frame (210) is provided with a shielding section (250) capable of shielding X-rays. The same applies hereinafter) is provided with a shielding section (250) capable of shielding X-rays.

[0043] The shielding unit (250) can completely shield X-rays generated by the X-ray tube (230) inside the frame (210) and radiated into the interior of the frame (210), thereby preventing the X-rays from leaking outside the frame (210). As a result, the shielding unit (250) can protect the subject, the operator operating the equipment nearby, and even other people near the gantry (200) from X-rays.

[0044] The shielding member (250) can be formed by bonding a lead plate to a plate surface inside the frame (210) or by coating or attaching barium or other alloys to the inner surface of the gantry (200).

[0045] The shielding part (250) can have a different thickness in response to the X-ray irradiation amount, taking into account the X-ray irradiation amount, etc.

[0046] The gantry (200) may be integrally provided with a chair-shaped support means (320) so that the breast can be inserted into the opening (213) and the legs, etc. can be positioned in the recessed part (215). Here, when the gantry (200) is tilted with respect to the floor while the subject sits on the support means (320) such as a chair (see 'θ' in FIG. 4), the subject's upper body may also tilt together with the gantry (200).

[0047] And, a moving means (400) including wheels is connected to the lower side of the supporter (300) so that the supporter (300) can move.

[0048] The fundamental principle of the present invention started from the prediction of Austrian mathematician Radon that if projection (transmission) data is obtained from various directions, a clear tomographic image can be reconstructed. Projection (transmission) data is data obtained by measuring the X-ray dose value transmitted through the human body by an X-ray detector (240) that detects the X-rays transmitted through the human body by irradiating them from various angles (e.g. 360 degrees) using X-rays transmitted through the human body and converting this into electrical intensity.

[0049] In order to convert the converted electrical intensity into each pixel value (i.e., a tomographic image), an arithmetic equation must be solved. This was realized only with the development of computers that made calculations possible in a short period of time, and is called a computed tomography system.

[0050] An X-ray tube (230) is a vacuum tube that generates and irradiates X-rays. The X-ray tube (230) applies a DC voltage of approximately 100,000 volts between the cathode and the anode, so that electrons generated at the cathode are attracted to the anode and collide with the anode, generating the kinetic energy of the electrons in another form, that is, in the form of X-rays.

[0051] By measuring the X-ray generated from the X-ray tube (230) and feeding back the X-ray dose to the X-ray power supply unit (630), accurate adjustment of the X-ray dose, automatic control of the dose, and protocol-based irradiation are possible, and such control is controlled through the control unit (500).

[0052] The X-ray tube (230) may include a new concept digital X-ray tube that is compact in size and has the highest efficiency in X-ray dose, can easily generate short and strong X-ray pulses, and can precisely control energy and dose.

[0053] For example, the X-ray tube (230) may include a digital X-ray tube of the nano cold-cathode field-emission type that can easily generate short and strong X-rays and precisely control energy and dose to provide excellent image quality while minimizing the required X-ray dose, and that does not require heating the cathode, so that a heating circuit is unnecessary and thus miniaturization is possible.

[0054] The X-ray detector (240) detects the X-rays that have passed through the subject in the X-ray tube (230), converts them into electrical intensity, and transmits data corresponding to the converted information to the data collection unit (610). That is, the X-rays emitted from the X-ray tube (230) reach the X-ray detector (240). Here, the X-ray detector (240) is arranged at a position opposite to the rotation center axis (CL) with respect to the X-ray tube (230), as shown in FIG. 3.

[0055] The X-rays generated from the X-ray tube (230) are irradiated by rotating the rotation gear (220) 360 degrees around the breast, and the amount of X-rays transmitted from each direction can be converted into electrical intensity in the X-ray detector (240). The X-ray detector (240) is composed of hundreds of semiconductors per column.

[0056] As illustrated in FIG. 3, the X-ray detector (240) may include a plurality of holes (241) and a plurality of detection units (242) configured to correspond to the plurality of holes (241), respectively. The holes (241) and the detection units (242) correspond one-to-one, respectively, and are formed in a grid shape. Each hole (241) may serve as a passage or guide tube that guides the X-rays emitted from the X-ray tube (230) and passing through the subject to the corresponding detection units (242). The detection units (242) may detect the X-rays received through each hole (241). At this time, the detection units (242) may be formed of hundreds of semiconductors per column as described above. The detection units (242) may correspond to each pixel of the image. That is, the size of the X-rays detected by each detection unit (242) may become the pixel value of each pixel of the image.

[0057] In order to generate X-rays with penetrating power, electrons are accelerated with a voltage of 100,000 volts and collided with the anode, so that the electrons are braked and their kinetic energy is converted into another form of energy, that is, X-rays. This is called braking radiation (more than 90% of the total X-rays generated). In addition, when electrons collide with each other, their energy levels are excited to different angles and then return to their original state, a small amount of characteristic radiation (generated in some specific frequency bands) is generated according to the energy difference. The braking radiation and characteristic radiation together are called generated X-rays. These X-rays are processed into a form that is as narrow and strong as possible (a form in which the average energy is increased) in a spectrum expressed with the frequency band as the x-axis and the dose as the y-axis.

[0058] In the present invention, the X-ray tube (230) can generate X-rays that are only helpful for image quality while minimizing exposure to the patient, and the X-ray detector (240) can measure the value of the amount of X-rays that has passed through the object and transmit the value to the data collection unit (610).

[0059] The data collection unit (610) collects and organizes values ​​received from each X-ray detector (240) in each direction and transmits them to the image reconstruction unit (640).

[0060] As previously explained, the X-ray tube (230) requires a strong and high DC high voltage.

[0061] The X-ray power supply unit (630) boosts commercial power to a high voltage, rectifies the high voltage to a DC voltage, and supplies the high voltage to an X-ray tube (230) that requires a DC voltage. The level of the high voltage DC voltage may vary depending on the amount of X-rays required for generation.

[0062] The X-ray power supply unit (630) can perform accurate dose control, automatic exposure control, automatic control according to a protocol, etc. based on feedback of the X-ray dose, and all of these controls or adjustments can be controlled by the control unit (500). In this way, the control unit (500) can control the overall operation of the breast tomography device (100) according to the present invention.

[0063] The image reconstruction unit (640) calculates the data received from the data collection unit (610) to determine the value of each pixel in the image. Here, the image reconstruction unit (640) reconstructs the image, and image reconstruction refers to a mathematical process of creating an image based on raw data, i.e., data transmitted from the data collection unit (610).

[0064] By obtaining the transmission value in each direction for each X-ray detector (240) (data collection) and calculating each pixel value in the form of a matrix based on this (image reconstruction), the cross-section itself or multiple cross-sections can be viewed in three dimensions.

[0065] As shown in the principle in Fig. 5, if we solve the horizontal sum a + b = 3 and c + d = 7 and the vertical sum a + c = 4 and b + d = 6 for each pixel of the image, we can obtain the values ​​a = 1, b = 2, c = 3, d = 4. In this way, we can find out the values ​​of each pixel by calculating from the data, but since we need to quickly calculate a large number of calculation equations to find out a large number of pixel values, we need a computer with a fast calculation speed.

[0066] The image reconstruction unit (640) can also be implemented as a function of the control unit (500), and performance can be improved by applying a better technology (e.g., an iterative reconstruction algorithm) than the conventional FBP (Filtered Back Projection) as an analysis technique. This algorithm is very excellent in converting the image electrical signal into each pixel value of a three-dimensional coordinate, so that noise can be compressed while obtaining excellent image quality, and thus the required X-ray dose can be additionally reduced.

[0067] The image display unit (620) displays the final single-layer image or the three-dimensional stereoscopic image obtained by combining single-layer images as a result derived from the image reconstruction unit (640).

[0068] The video display unit (620) can also monitor all captured images simultaneously. This allows multiple organically connected control elements to be displayed, facilitating control of the entire device.

[0069] The operation console (510) includes a touch panel, a keyboard, a mouse, and a track ball, and allows the user to input necessary information to control the image and gantry (200) in scan mode.

[0070] Communication between the data collection unit (610) and the operation console (510) can also be controlled by the control unit (500) to efficiently control the spiral rotation for improving the signal-to-noise ratio by utilizing the deviation of the data.

[0071] The operation process of a breast tomography device (100) having this configuration is described in detail as follows.

[0072] First, the examinee sits on the supporter (320) of the supporter (300) and positions the breast, which is the examinee, in the opening (213).

[0073] In the X-ray power supply unit (630), the voltage charged in the commercial power supply or battery is boosted and rectified, and the processed high voltage in a pulse format suitable for the X-ray generation conditions is applied to the X-ray tube (230). Accordingly, X-rays are irradiated in the X-ray tube (230).

[0074] The generated X-rays are irradiated to the breast while rotating 360 degrees with the breast as the target of the examination by the rotation of the rotating gear (220).

[0075] X-rays that have passed through the breast are received by the X-ray detector (240) and converted into electrical intensity according to the X-ray dose. The data collection unit (610) organizes the data converted into electrical intensity in each direction and each X-ray detector (240) and sends it to the image reconstruction unit (640), and the image reconstruction unit (640) calculates each pixel value by calculating this data to create a tomographic image.

[0076] The obtained single-layer image is displayed on the image display unit (620) and read immediately or transmitted to the workstation (710) and the hospital's image information processing system (720) and stored, so that it can be analyzed further and viewed by a doctor when necessary.

[0077] All of these processes are performed through the control unit (500), and are controlled by a doctor or authorized user inputting commands through the operation console (510).

[0078] Here, the imaging process begins with positioning the breast in the imaging position. When positioning the specimen in the imaging position solely by gravity, a characteristic of the breast computed tomography device (100), a very wide imaging area (coverage) that includes even the lymph nodes (Lymph Nodes) can be secured structurally (with the help of gravity), allowing for rapid detection of metastasis. Furthermore, it is possible to detect actual changes at the pixel level, or almost at the cell level, enabling precise diagnosis.

[0079] That is, the breast computed tomography device (100) can utilize 3D pixel (spatial pixel, volume pixel: Voxel) shift and digital subtraction software because it sets the shooting position only by relying on gravity in a certain direction regardless of time and space, in addition to its own advantages. Accordingly, it is possible to establish a system for early detection, diagnosis, and tracking, observation, and management of actual changes in the tissue cell unit of breast cancer, and to overcome the technical and scientific limitations of medical AI using this and operational limitations such as lack of infrastructure, thereby maximizing the function improvement and utilization of AI.

[0080] When taking a picture using a breast tomography device (100) according to the present invention for breast cancer diagnosis, only gravity, which is a constant force, is applied to the breast, which is the object of the picture, regardless of time and place, so a breast image of almost the same shape can be obtained each time the picture is taken.

[0081] Accordingly, by utilizing Voxel Shift software, it is easy to match all coordinates of each pixel, which is about the size of a tissue cell in each cross-section (which becomes a 3D image when collected), with those of the previous captured image.

[0082] In addition, by applying digital subtraction between each pixel of the same coordinates in the image before the shooting date and the image on the shooting date, the change in each pixel value can be obtained as an actual value in a consistent unit (a unit called 'Hounsfield unit' in terms of X-ray attenuation value).

[0083] Accordingly, very rapid detection and accurate diagnosis are possible from the actual changes in the breast at the early microscopic stage, and the progress of tissue changes can be tracked accordingly, enabling management of breast cancer at the tissue cell level.

[0084] This is a specialized application of technology for breast cancer diagnosis, rather than a general, schematic application of AI. It is expected to overcome the current scientific and technological limitations of breast cancer diagnosis AI, as well as the lack of infrastructure, and to be significantly utilized across the entire breast cancer field in the future.

[0085] In particular, it will be possible to maximize the use of AI, which will be more useful in mobile diagnostic breast computed tomography devices.

[0086] During the operation of the breast tomography device (100), the noise generated by motion artifacts (movement of the subject) is less as the rotational X-ray generation is shorter. In other words, the faster the rotational scan, the less movement there is, and thus a clearer image can be obtained.

[0087] The rotary gear (220) can move in the forward and backward directions during X-ray scanning. Specifically, the rotary gear (220) can move in the forward and backward directions based on the breast of the subject inserted into the opening (213). This is to obtain X-ray images of various parts of the breast through the forward and backward movement and rotation of the rotary gear (220) during X-ray scanning.

[0088] In this way, by moving the rotating gear (220) back and forth during X-ray scanning, image data with deviation can be obtained and superimposed. That is, in scan mode, the deviation signal can be superimposed by scanning multiple times as quickly as possible with an adjustable scan interval (Scan Pitch), so that an image with superior quality and a better signal-to-noise ratio (S / N ratio) can be obtained, which has the effect of further reducing the required dose.

[0089] As the rotating gear (220) rotates 360 degrees, X-rays are irradiated onto the breast, penetrating the lesion area at all angles of the breast to obtain an image.

[0090] Therefore, basically, by rotating the rotation gear (220) once, an image of the lesion area at a 360-degree angle of the breast can be obtained, but this operation can be repeated several times to obtain the clearest image.

[0091] At this time, the generated X-rays are propagated in a radial direction, and all X-rays other than those reaching the X-ray detector (240) are unnecessary and harmful to the human body. These X-rays are radiation harmful to the human body. Therefore, considering only the safety for the human body, the less the amount of used and leaked X-rays, the better. Even excluding the subject, it is desirable to reduce the exposure amount of these X-rays to the operator of the device, etc. Therefore, it is important to shield them so that they are not transmitted to the outside. This shielding is achieved by the shielding unit (250) described above, and specifically, it is desirable that the amount of leakage X-rays be below the standard value (domestic standard: 2.58 C / kg or 100 mR per week). To this end, in the present invention, an X-ray shielding unit (250) formed on the inner surface of the frame (210) of the gantry (200) is provided, and has a structure capable of shielding X-rays leaking to the outside.

[0092] Meanwhile, the smaller the amount of X-rays generated and emitted from the X-ray tube (230), the smaller the amount of X-rays reaching the X-ray detector (240), and the lower the possibility of obtaining a clear image. Therefore, in order to obtain a clear image, it is necessary to generate a high voltage from the X-ray power supply unit (630) to apply a higher voltage to the X-ray tube (230) to generate a large amount of X-rays. In addition, although the amount of X-ray exposure can be reduced while improving the quality of the image by processing (filtering) the X-rays, the amount of X-rays leaking to the outside still remains large, which may be harmful to the human body.

[0093] To solve these problems, the present invention applies new technology (active shielding) to reduce the required X-ray dose and forms an X-ray shielding section (250) on the inner surface of the frame (210) (passive shielding) to ensure the safety of the human body.

[0094] By shielding the X-rays internally in this way, there is no need to install X-ray shielding on the entire outer wall of the room where the breast tomography device (100) is installed, and restrictions on the installation location can be minimized.

[0095] In addition, in the present invention, a high-sensitivity X-ray detector (240) is used, so that a high-resolution image can be obtained using a small amount of X-rays (active shielding). This can be achieved by using a perovskite-type X-ray detector or an X-ray detector with equivalent performance, which has a sensitivity that is far superior to that of conventional general X-ray detectors, thereby significantly reducing the required dose.

[0096] This perovskite-type X-ray detector (240) has a sensitivity 20 times higher than that of a conventional detector, and requires less than 1 / 10 of the X-ray dose, so it is highly desirable for protecting the human body of patients and people around them.

[0097] The frame (210) of the present invention uses a high-sensitivity X-ray detector (240), so that a small-capacity X-ray tube can be made into a cold cathode type, and thus the entire device can be made light and small while reducing the amount of energy required.

[0098] By forming the X-ray shield (250) on the inner surface of the frame (210), the risk of harm to the human body is reduced. By combining a moving means (400) including wheels with the gantry (200), mobility can be improved and installation can be facilitated. By using the gantry (200) for mobile purposes, patients who have difficulty coming to hospitals, such as in island regions, can be directly visited and photographed.

[0099] According to the present invention, all dose reduction elements are combined to significantly reduce the dose and the radiation exposure or risk of radiation exposure to patients and people nearby is also significantly reduced by passive shielding inside the frame (210) with heavy metal of a thickness of less than 1 / 10 of the X-ray dose, and the energy consumption requirement can be minimized, and the portability can be easily achieved and the range of use can be maximized.

[0100] Meanwhile, AI diagnosis is being utilized to supplement the errors that can occur in diagnosis based on human vision, but in the current diagnosis situation where it is based on two-dimensional images, or even three-dimensional, it relies on devices with physical and clinical limitations, or relies only on inconsistent diagnostic information without sufficient clinical research, there may be clinical, technological, scientific, and operational limitations.

[0101] Accordingly, a general and chronic lack of clinical research, technological and scientific limitations, and a lack of infrastructure are key factors that make it difficult to apply AI technology to the medical field.

[0102] In addition, the variability of medical data used for AI learning is also a problem. Since the data varies depending on the patient's gender and age, data generation conditions, treatment environment, and time, it is difficult for AI to generalize it. Therefore, it is difficult to consistently standardize self-learning data. Ultimately, further development is still needed to create AI that can be introduced into the medical field.

[0103] To this end, if specialized, real-world data for each diagnosis could be provided, clinical data with consistent evaluation metrics would facilitate more active and generalized expert review. Furthermore, providing real-world, critical information unaffected by random variables would facilitate consistent generalization, making it easier to build the necessary infrastructure and enabling consistent evaluation and management of continuously evolving AI.

[0104] In addition, there are currently few methods that can make a perfect diagnosis at once, and moreover, there are currently few suitable methods to track, observe, or manage cancer tissue detected through visual diagnosis using all methods at the tissue cell level. However, if it becomes possible to immediately detect changes in each tissue cell in the future, all of the above will become possible.

[0105] However, the reason why it is difficult to detect changes in tissue cells at present is that almost all breast cancer diagnostic equipment that can look inside the breast has physical and clinical limitations, even though there is a technology called digital subtraction that can detect changes.

[0106] In addition, it is very difficult to align (align or register) each pixel value of the images before and after shooting, that is, all pixel coordinates of each tissue cell, so it is impossible to compare pixels with the same coordinates.

[0107] Digital Breast Tomosynthesis (DBT), which is closest to three-dimensional imaging in the conventional technology and has relatively few clinical and physical limitations, also requires breast compression. However, since various factors such as the intensity, direction, reaction, elasticity, gravity, and overlap of the compression act simultaneously on each pixel, it is difficult for each pixel to always have a consistent coordinate every time it is captured. Therefore, it is not easy to match the coordinates of each pixel in the images before and on the day of capture, and it is difficult to identify changes in the tissue cell unit of each coordinate.

[0108] That is, all imaging diagnostic devices except for the breast tomography device (100) according to the present invention have clinical and physical limitations or it is structurally difficult to match the coordinates of each pixel of the pre- and post-images, making it difficult to obtain detailed changes in each pixel, i.e., tissue cells, as actual values, and thus, there are difficulties in early detection, accurate diagnosis, and follow-up observation and management.

[0109] In other words, in a healthcare environment where comprehensive diagnostic results are directly linked to life, high data reliability and the accuracy and specificity of the information provided are crucial. Furthermore, without the provision of precise and consistent, actionable data, free of clinical and physical limitations, the realization of essential functions such as early detection, accurate diagnosis, tracking, observation, and management becomes significantly more challenging. Furthermore, the use of AI to supplement these capabilities is limited. Therefore, the provision of reliable and robust data specifically for breast cancer is essential.

[0110] Accordingly, the breast tomography device (100) of the present invention can provide a perfect 3D image (Isotropic 3D Image) for breast diagnosis, and has a structure in which the shooting position of the breast can be set only by gravity, which is a constant force regardless of time and place, since no external force such as breast compression is applied. Accordingly, if the angle of the subject and the shooting conditions are the same, a breast image of almost the same shape can always be obtained, so that all coordinates of each pixel of the image before the shooting day and the image on the shooting day can be easily matched.

[0111] The present invention aims to realize and utilize information on changes in breast tissue cells without clinical or physical constraints for very rapid lesion detection, accurate early diagnosis, tracking and monitoring breast cancer progression, and establishing a management system. Furthermore, to address the problems and limitations of current AI, which exist due to the blanket application of AI to uncertain and inconsistent information or data and the learning of data that is significantly influenced by confounding variables, the present invention applies a technology specialized in breast cancer diagnosis to provide consistent, real-world change values ​​at the tissue cell level, thereby overcoming the clinical, scientific, and technological limitations of current AI, as well as insufficient infrastructure.

[0112] In the actual process in which the software generates information based on the computer controlling the aforementioned gantry and the entire device, the operation console (510) allows the operator to input and give instructions to the computer, the rotation gear (220) of the gantry (200) rotates; the X-rays that have passed through the subject are received by the X-ray detector (240) that rotates symmetrically with the X-ray tube (230); the data are collected by the data collection unit (610) and transmitted to the image reconstruction unit (630); and the three-dimensional pixel value, i.e., the voxel value, of each image is calculated based on the received data and transmitted to the image display unit (620) to be displayed as an image.

[0113] Accordingly, the breast tomography device (100) that performs this process can obtain the same or substantially identical breast images between the images before the shooting day and the images on the shooting day, as long as the same imaging conditions (KV, mA, Sec) are applied to the same angle of the gantry (200) because the same constant gravity is applied regardless of time and place during the mammography.

[0114] In fact, since the breast tomography device (100) of the present invention positions the subject, i.e., the breast of the subject, within the opening (213) due to its own weight, it is possible to obtain breast images that are almost identical between the images before and on the shooting day, regardless of time and place, as long as the angle of the gantry (200) does not change or the shooting conditions (KV, mA, Sec) do not change.

[0115] Accordingly, the tomographic images of almost the same shape before the shooting date and the tomographic images of the shooting date obtained from the breast tomography device (100) of the present invention are called up from H / W (e.g., Work Station), and the preset voxel shift software is applied to compare the pixel values ​​(X-ray attenuation value: 'Hounsfield' unit) of the image before the shooting date with the pixel values ​​of the image on the shooting date, and each pixel is moved so that the same values ​​match. After digital subtraction between pixels at the same location with reference to the image on the shooting date, the coordinates of the pixels match, and the unchanged pixel values ​​become "0" (or close to "0"), and the changed pixel values ​​(values ​​other than "0") can be visually displayed in color to emphasize them or provide specific actual values.

[0116] Figure 6 is a drawing that briefly explains this principle, and Figure 6(a) is an image on the shooting day, Figure 6(b) is an image before the shooting day, and Figure 6(c) is a drawing that shows the change in pixel value by digitally subtracting the pixel value at each pixel by pixel shifting the image on the shooting day to the image before the shooting day.

[0117] As can be seen in Fig. 6(c), if the pixel value of each pixel in the image before the shooting date and the image on the shooting date are the same, the number '0' is displayed, and if they are different, an integer other than '0' (including a decimal value if necessary) is displayed. The number displayed in each pixel means that the pixel value in the same pixel has changed, and this change in pixel value indicates an abnormality in the subject. In other words, if a change in pixel value is detected in the same pixel in the two images, it can be determined that an abnormality has occurred in the subject. The image reconstruction unit reconstructs the image reflecting the change in pixel value in this way.

[0118] That is, Fig. 6 is an explanation of the principle of finding out the change in pixel value through digital subtraction after matching the coordinates of each pixel of the images before and after the shooting date by pixel shifting the images of the same person before the shooting date, which are called up from the image information processing system (PACS, not shown), based on the images of the shooting date transmitted from the image display unit (620) in H / W (e.g., Work Station).

[0119] For example, in the example of Fig. 6(c), by pixel-shifting the image before the shooting date of Fig. 6(b) to the image on the shooting date of Fig. 6(a) (e.g., overlapping the two images), and calculating the difference in pixel values ​​at each pixel through digital subtraction, it can be seen that, except for pixel e among all pixels of the image, pixels a to i, there is no change in pixel value. That is, the result of the digital subtraction of the pixel value at each pixel is 0. However, in pixel e, the pixel value is 8 in the image before the shooting date, but 5 in the image on the shooting date, so the result of the digital subtraction is -3. This means that the pixel value of pixel e has changed in the image on the shooting date after the image before the shooting date.

[0120] In the breast tomography device (100) of the present invention, image analysis is possible according to such pixel shift, and an image diagnosis can be made through such image analysis.

[0121] Meanwhile, even with a brain-composite computed tomography (BCT) device that can position a subject using only a constant gravity regardless of time and place, it is not always easy to match the coordinates of each pixel due to horizontal movement, rotation, enlargement, contraction, and new tissue creation of each tissue cell. This is especially true in three-dimensional BCT. However, by performing a binding voxel shift, which moves the three-dimensional pixels, i.e. voxels, of the images before the shooting date to the images on the shooting date in the X and Y axes, the voxel values ​​can be matched more quickly and accurately (here, the tomographic image becomes two-dimensional in the X and Y axes, but when these tomographic images are used together, it becomes three-dimensional in the X, Y, and Z axes).

[0122] Shifting individual voxels takes a lot of processing time. However, as shown in Fig. 7, shifting multiple voxels in groups can process the coordinate matching of pixels more quickly. In this case, if the coordinates in which the direction and distance (vector) for shifting multiple voxel groups to the matched coordinates are the same (here, the value of the voxel group is the average value of the voxels, the position of the same value by adding all voxels, or the "0" position by simultaneous digital subtraction), the result can be obtained faster by applying the vector value to each voxel, and the result can be obtained even faster by performing voxel shifting and digital subtraction simultaneously.

[0123] If the range of error in coordinate alignment is excessively exceeded (misalignment or misregistration) due to excessive movement during shooting, plastic surgery, breastfeeding, or sudden obesity, it may take a considerable amount of time to align the coordinates. In such cases, it may be possible to adjust them visually or manually based on prior knowledge and experience.

[0124] As AI develops further in the future, it is expected that it will play an active role, encompassing not only the above functions but also information generation, rather than the current passive state of receiving information and making a diagnosis. Therefore, AI can independently generate consistent and specific real values, thereby overcoming scientific, technological, and operational limitations and providing much more efficient and accurate management maximized by AI. In addition, the attending physician can provide more active and accurate predictions and close prognostic management to the patient.

[0125] Figure 7 is a diagram illustrating a more realistic and faster-processing bundle of voxels, in addition to Figure 6. As previously explained, processing by bundling voxels significantly speeds up the process. However, bundling too many voxels may result in insufficient detail, so selecting an appropriate bundle of voxels is crucial.

[0126] In Fig. 7, each voxel bundle value can be used by adding or averaging the values ​​of all bundled voxels. In addition, voxel bundles with the same value can be voxel-shifted and then digitally subtracted for each voxel to determine the change value. Alternatively, voxel shifting and digital subtraction can be performed simultaneously to calculate the direction and value of movement toward the position that becomes "0" (or closest to "0"), i.e., a vector value, and then the same vector value can be applied to each voxel in the bundled voxels to more quickly process the coordinate matching of each voxel while also determining the change value.

[0127] To facilitate understanding, we will illustrate the simultaneous execution of voxel shifting and digital subtraction with reference to an example in Figure 7. In the image in Figure 7, numbers represent voxel values, and letters indicate voxel locations. To facilitate voxel shifting, it is desirable to select a voxel in the center of the image and shift it to a voxel with a voxel value of 0.

[0128] For example, in the example of Fig. 7, the middle m voxel is voxel-shifted to u voxel with voxel value 0. To do this, the voxel is shifted by -2 in the X-axis and -2 in the Y-axis. In other words, the direction and value of the voxel shift are -2 in the X-axis and -2 in the Y-axis, respectively.

[0129] In this way, the voxel value at each voxel changes by -4. This can be seen in other voxels as well. For example, if voxel e is also voxel-shifted by -2 in the X-axis and -2 in the Y-axis, it shifts by m pixels, resulting in a voxel value change of -4 (from 8 to 4). In addition, voxel c is also shifted by k voxels, resulting in a voxel value change of -4 (from 6 to 2). As in Fig. 7, the shift is made in the direction and value that becomes "0" at the center of the image, and all voxels included in the voxel bundle here are applied with the same vector value (X-2, Y-2).

[0130] In this way, the breast tomography device (100) of the present invention can produce quick results by simultaneously performing voxel shifting and digital subtraction, thereby reducing the time and cost required to shift all pixels. To this end, the image reconstruction unit (630) reconstructs an image reflecting the voxel values ​​of each voxel, and the image display unit (620) displays this, thereby allowing visual confirmation of abnormal areas.

[0131] At this time, all voxel shifts and digital subtractions are automatically handled by software, but can be done manually as there is no need to always view them in real time, and this is preferable for use when performing minor corrections.

[0132] The process of obtaining an image using a breast tomography device (100) according to the present invention and the process of obtaining the change value of each pixel are described in detail as follows.

[0133] First, the subject removes his / her upper garment and places his / her breasts into the breast opening (213). In this case, the gantry (200) is preferably tilted relative to the supporter (300), as illustrated in FIG. 4, and the subject is stably supported by the support means (320). At this time, the captured image becomes the image from the shooting date. Of course, there are images captured before the shooting date under the same conditions, and these images become the images from before the shooting date.

[0134] To this end, in order to obtain the same type of image of the same patient, the same gantry angle and the same shooting conditions (KV, mA, Sec, Pulse Rate) must be confirmed on the previous and current shooting days before starting shooting.

[0135] The device operator checks whether the breast, which is the subject of the examination, is correctly inserted into the breast opening (213) and instructs the start of the photographing through the operation console (510). In accordance with this instruction, the control unit (500) operates the X-ray power supply unit (630) to apply high voltage to the X-ray tube (230).

[0136] At the same time, the control unit (500) drives the motor of the rotation gear (220) to rotate the rotation gear (220). As a result, the X-ray tube (230) and the X-ray detector (240) can rotate while maintaining a point-symmetrical relative position.

[0137] The X-ray tube (230) to which a high voltage is applied rotates and emits X-rays. These X-rays are output in a radial direction as indicated by a thick arrow in Fig. 2. The output X-rays pass through the breast, which is the subject of examination, and reach the X-ray detector (240). The X-rays that reach the tube are converted into electrical signals in the X-ray detector (240), and are collected and processed in the data collection unit (610), transmitted externally, and reconstructed, thereby completing preparations for comparison with images from before the shooting date.

[0138] In the H / W (Work Station), the coordinates of the image on the shooting date are automatically or manually aligned with the image of the same patient stored in the hospital's Picture Archiving Information Processing System (PACS) using the preset Binding Voxel Shift software based on the image on the shooting date (mask). After the two images are aligned, digital subtraction is performed or, as in Fig. 7, digital subtraction and coordinate alignment are performed simultaneously to obtain the change value of each pixel. This change value can be visually emphasized (Coloring), or the actual change value can be provided as an X-ray attenuation value (unit: Hounsfield), or it can be provided to AI.

[0139] In this way, by providing information on tissue cell changes from the microscopic level, it is possible to detect lesions at the breast tissue cell level very quickly and to track and monitor the progression of breast cancer even at the microscopic level, even if it is not immediately apparent. Furthermore, it has the advantage of allowing monitoring to begin with only changes in tissue cells, rather than after breast cancer has developed. Furthermore, it allows for the establishment of a comprehensive management system for all patients' breast cancer progression, starting from the microscopic changes in tissue cells. This will allow AI, which is expected to be increasingly utilized in the future, to overcome the limitations of current technologies and maximize its scope of application.

[0140] The present invention described above is capable of various substitutions, modifications, and changes within the scope of the technical idea of ​​the present invention by a person having ordinary skill in the art to which the present invention pertains, and is not limited to the above-described embodiments and attached drawings.

[0141] Accordingly, it can also be used in similar principle devices such as simulation treatment CT device (BCT Simulator), tomotherapy device, veterinary CT, and extremity and small part CT.

[0142] In addition, it can be seen that the objects and advantages of the present invention can be easily realized by the means and combinations thereof shown in the patent claims.

[0143] The present invention is to provide a breast computed tomography (BCT) device having many advantages in breast diagnosis as described above, miniaturized to produce a lower X-ray dose than all X-ray diagnostic devices, and a self-shielding and movable gantry that is easy and convenient to shield the generated X-ray dose, and a breast computed tomography device having the same.

[0144] In addition, the purpose is to provide a self-shielding and movable gantry and a breast tomography device having the gantry, which can be freely installed or moved to maximize space utilization.

[0145] Furthermore, the purpose is to provide a self-shielding and movable gantry and a breast tomography device having the gantry, which can be made lightweight and miniaturized to reduce energy consumption and increase economic efficiency at the same time, and can be freely moved into space to increase space utilization.

Claims

1. A frame having a box shape with a space formed inside; A rotary gear rotatably coupled to the interior of the above frame; An X-ray tube coupled to one side of the above rotating gear and generating X-rays; An X-ray detector coupled to the other side of the above-mentioned rotating gear, capable of rotating around a rotational center axis and moving forward and backward with respect to the subject to be examined, which receives X-rays generated from the X-ray tube and passing through the subject to be examined and converts them into electrical signals; A shield formed over the entire inner surface of the frame except for an opening into which the test subject is inserted on one side of the frame, and shielding the X-rays generated from the X-ray tube from leaking out of the frame; An image reconstruction unit that reconstructs an image formed by a signal converted from the above X-ray detector; and Includes an image display unit that displays an image reconstructed by the image reconstruction unit, The above image reconstruction unit is a breast tomography device that calculates changes in pixel values ​​by digitally subtracting the same pixel between the two images by pixel-shifting the image of the previous day of the shooting to the image of the shooting day, and reconstructs an image in which the calculated changes are reflected for each pixel.

2. In claim 1, The above image reconstruction unit is a breast tomography device that, if the image is a three-dimensional stereoscopic image, groups voxels, which are three-dimensional pixels, into a plurality of bundles, shifts the central voxel of the image formed by the voxel bundles to a voxel with a voxel value of 0, calculates a change in the voxel value through the digital subtraction, and then reconstructs an image in which the calculated change is reflected for each voxel.

3. In claim 1, The X-ray detector includes a plurality of holes each guiding an X-ray that has passed through the subject and is emitted from the X-ray tube, and a plurality of detection units configured to correspond to each of the plurality of holes and detecting the X-rays received through each of the holes, wherein the detection units are made of a semiconductor, and the plurality of detection units correspond to each pixel of the image. A breast tomography device.

4. In claim 3, A breast tomography device in which the size of the X-rays detected by the plurality of detection units corresponds to the pixel value of each pixel of the image.

5. In claim 1 The above image reconstruction unit is a breast tomography device that highlights pixels with the change in the image in which the calculated change is reflected for each pixel by coloring them.

6. In claim 1, A breast computed tomography device in which the shielding part includes a lead plate formed over the entire inner surface of the frame.

7. In claim 1, A breast tomography device characterized in that the test object includes a breast.

8. In claim 1, A breast tomography device configured such that the frame is tiltable relative to a horizontal plane and the subject positioned in the opening is maintained in a state in which the subject is directed downward by gravity due to the tilting.

9. In claim 1, A breast tomography device comprising a moving means including wheels on the lower side of the frame to enable the frame to move.

10. In claim 1, The above X-ray detector is a breast tomography device that causes the rotating gear to move up and down during the X-ray scanning to scan multiple times at a set scan interval (scan pitch) to obtain image data with deviations by overlapping them.

Images