Cooling container, X-ray apparatus, and X-ray image processing method

Abstract

To provide a cooling container capable of easily obtaining an X-ray image of a sample having a size larger at temperature lower than room temperature, and also facilitating incorporation into an X-ray imaging apparatus.SOLUTION: A cooling container includes: a hollow container; and a heat insulation container for storing the hollow container. The hollow container includes a pipe and a bottom plate. A sample is soaked in a cooling liquid and is supported by at least one of the pipe and the bottom plate. The pipe and the heat insulation container are formed of a low-density material. A first opening communicating with a storage space is arranged at a second end of the pipe. A through-hole communicating with the first opening is arranged in the heat insulation container.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a cooling container, an X-ray apparatus, an X-ray image processing apparatus, and an X-ray image processing method.

Background Art

[0002] Toshiaki Takeya, Development of Low-Temperature Phase-Contrast X-ray CT Technology, AIST TODAY, issued on November 1, 2006, Vol. 6, No. 11, p. 22-23 (Non-Patent Document 1) discloses a low-temperature sample container used in a low-temperature phase-contrast X-ray computed tomography (CT) measurement method. This low-temperature sample container includes a metal cooling container body and a metal liquid container.

[0003] The cooling container body houses a refrigerant and a liquid container. The liquid container houses a liquid and a sample immersed in the liquid. A heater for controlling the temperature of the liquid is provided in the liquid container. The heater is connected to a temperature regulator outside the low-temperature sample container through electrical wiring. A thermocouple is connected to the temperature regulator. The thermocouple is in contact with the liquid. The sample is suspended from a rotating shaft. X-ray transmission windows are provided in the cooling container body and the liquid container. While rotating the rotating shaft to rotate the sample, X-rays passing through the X-ray transmission windows of the cooling container body and the liquid container are irradiated onto the sample. The X-rays that have passed through the sample are detected.

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the low-temperature sample container of Non-Patent Document 1, the sample is suspended from a rotating shaft. Since it is difficult to suspend a sample having a large size from the rotating shaft, it is difficult to obtain an X-ray image of a sample having a large size. Further, the low-temperature sample container of Non-Patent Document 1 is provided with a heater and a thermocouple in order to control the temperature of the liquid. Therefore, as the size of the low-temperature sample container increases, it is necessary to provide electrical wiring to the low-temperature sample container. It is difficult to incorporate the low-temperature sample container into the X-ray imaging apparatus without modifying the X-ray imaging apparatus.

[0006] The present disclosure has been made in view of the above problems, and an object of the first aspect of the present disclosure is to more easily obtain an X-ray image of a sample having a larger size at a low temperature lower than room temperature, and to provide a cooling container that can be easily incorporated into an X-ray imaging apparatus. An object of the second aspect of the present disclosure is to provide an X-ray apparatus that can more easily obtain an X-ray image of a sample having a larger size at a low temperature lower than room temperature and can utilize an X-ray imaging apparatus. An object of the third aspect of the present disclosure is to provide an X-ray image processing apparatus and an X-ray image processing method suitable for the cooling container of the present disclosure.

Means for Solving the Problems

[0007] The cooling container of the present disclosure includes a hollow container and a heat insulating container that houses the hollow container. The hollow container includes a tube and a bottom plate. The tube includes a first end and a second end opposite to the first end. The bottom plate closes the first end of the tube. A sample and a coolant for cooling the sample are housed in a housing space defined by the tube and the bottom plate. The sample is immersed in the coolant and supported by at least one of the tube or the bottom plate. The tube and the heat insulating container are formed of a low-density material. A first opening communicating with the housing space is provided at the second end of the tube. A through hole communicating with the first opening is provided in the heat insulating container.

[0008] The X-ray apparatus of the present disclosure includes an X-ray imaging apparatus and the cooling container of the present disclosure. The X-ray imaging apparatus includes an X-ray source that emits X-rays, a stage that supports the cooling container, and an X-ray detector that detects the X-rays that have passed through the cooling container.

[0009] The X-ray image processing apparatus of the present disclosure includes an X-ray image reception unit that receives an X-ray image of a sample acquired by imaging the sample at a low temperature lower than room temperature for a first period of time, and an image processing unit. The image processing unit inputs the X-ray image of the sample into a neural network and generates a corrected X-ray image of the sample that is clearer than the X-ray image of the sample. The neural network is generated by learning using a learning dataset. The learning dataset includes a first reference X-ray image acquired by imaging a reference sample for a second period of time without cooling the reference sample, and a second reference X-ray image acquired by imaging the reference sample for a third period of time without cooling the reference sample. The second period of time is 0.5 times or more and 2.0 times or less the first period of time. The third period of time is longer than the first period of time and longer than the second period of time.

[0010] The X-ray image processing method of the present disclosure includes a step of acquiring an X-ray image of a sample by imaging the sample at a low temperature lower than room temperature for a first period of time using the X-ray apparatus of the present disclosure, and a step of inputting the X-ray image of the sample into a neural network and generating a corrected X-ray image of the sample that is clearer than the X-ray image of the sample. The neural network is generated by learning using a learning dataset. The learning dataset includes a first reference X-ray image acquired by imaging a reference sample for a second period of time without cooling the reference sample using the X-ray apparatus of the present disclosure, and a second reference X-ray image acquired by imaging the reference sample for a third period of time without cooling the reference sample using the X-ray apparatus of the present disclosure. The second period of time is 0.5 times or more and 2.0 times or less the first period of time. The third period of time is longer than the first period of time and longer than the second period of time.

Advantages of the Invention

[0011] According to the cooling container of the present disclosure, an X-ray image of a sample having a larger size at a low temperature lower than room temperature can be obtained more easily. The cooling container of the present disclosure can be easily incorporated into an X-ray imaging apparatus.

[0012] According to the X-ray apparatus of the present disclosure, an X-ray image of a sample having a larger size at a low temperature lower than room temperature can be obtained more easily, and an X-ray imaging apparatus can be used.

[0013] The X-ray image processing apparatus of the present disclosure is an X-ray image processing apparatus suitable for the cooling container of the present disclosure in which the X-ray imaging time at a low temperature lower than room temperature is shortened. The X-ray image processing method of the present disclosure is an X-ray image processing method suitable for the cooling container of the present disclosure in which the X-ray imaging time at a low temperature lower than room temperature is shortened.

Brief Description of Drawings

[0014]

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Embodiments for Carrying Out the Invention

[0015] [Description of Embodiments of the Present Disclosure] First, the embodiments of the present disclosure will be listed and described.

[0016] (1) The cooling container 5 of the present disclosure includes a hollow container 20 and a heat insulating container 35 that houses the hollow container 20. The hollow container 20 includes a tube 22 and a bottom plate 21. The tube 22 includes a first end 22a and a second end 22b opposite to the first end 22a. The bottom plate 21 closes the first end 22a of the tube 22. A sample 30 and a coolant 33 for cooling the sample 30 are housed in an accommodation space 22e defined by the tube 22 and the bottom plate 21. The sample 30 is immersed in the coolant 33 and supported by at least one of the tube 22 or the bottom plate 21. The tube 22 and the heat insulating container 35 are formed of a low-density material. A first opening 23 communicating with the accommodation space 22e is provided at the second end 22b of the tube 22. A through hole 39 communicating with the first opening 23 is provided in the heat insulating container 35.

[0017] Since the tube 22 and the heat insulating container 35 are formed of a low-density material, the tube 22 and the heat insulating container 35 can transmit X-rays 3a. The sample 30 is immersed in the coolant 33 and supported by at least one of the tube 22 or the bottom plate 21. Therefore, an X-ray image 60 of the sample 30 having a larger size at a temperature lower than room temperature can be obtained more easily.

[0018] In the cooling container 5 of the present disclosure, the first opening 23 is provided at the second end 22b of the tube 22, and the through hole 39 is provided in the heat insulating container 35. During imaging of the fluoroscopic X-ray image of the sample 30, the temperature of the sample 30 and the coolant 33 gradually rises, and even if a part of the coolant 33 changes into a gas, this gas is discharged to the outside of the cooling container 5 through the first opening 23 and the through hole 39. The cooling container 5 can be prevented from being damaged by this gas. Therefore, the temperature adjustment function can be omitted from the cooling container 5. The cooling container 5 of the present disclosure can be easily incorporated into the X-ray imaging apparatus 2 without modifying the X-ray imaging apparatus 2. The cost of the cooling container 5 can be reduced. The fact that the cooling container 5 does not have a temperature adjustment function in this specification means that an active temperature adjustment element (for example, a Peltier element or a heater) for actively adjusting the temperature of the coolant 33 and the temperature of the sample 30 is not provided in the cooling container 5.

[0019] The cooling container 5 of the present disclosure includes a heat-insulating container 35. Therefore, even if the cooling container 5 does not have a temperature control function, it is possible to gently slow down the temperature rise of the sample 30 and the cooling liquid 33 during imaging of the X-ray image 60 of the sample 30. It is possible to extend the time for imaging the X-ray image 60 of the sample 30 at a low temperature lower than room temperature. It is possible to improve the sharpness of the X-ray image 60 of the sample 30 at a low temperature lower than room temperature.

[0020] (2) In the cooling container 5 of (1) above, the tube 22 has a cylindrical shape. The outer surface of the portion of the heat-insulating container 35 that covers the tube 22 has the shape of a cylindrical outer surface.

[0021] Therefore, the cooling container 5 can be arranged closer to the X-ray source 3 of the X-ray imaging apparatus 2. The magnification of the X-ray image 60 of the sample 30 can be increased.

[0022] (3) In the cooling container 5 of (1) or (2) above, the tube 22 is in contact with both the cooling liquid 33 and the heat-insulating container 35.

[0023] Therefore, the cooling container 5 has a simple configuration. The cooling container 5 can be easily incorporated into the X-ray imaging apparatus 2 without modifying the X-ray imaging apparatus 2. The cost of the cooling container 5 can be reduced.

[0024] (4) In any of the cooling containers 5 of (1) to (3) above, the heat-insulating container 35 covers all the outer surfaces 22c of the tube 22.

[0025] Therefore, it is possible to gently slow down the temperature rise of the sample 30 and the cooling liquid 33 during imaging of the X-ray image 60 of the sample 30. It is possible to extend the time for imaging the X-ray image 60 of the sample 30 at a low temperature lower than room temperature. It is possible to improve the sharpness of the X-ray image 60 of the sample 30 at a low temperature lower than room temperature.

[0026] (5) In any of the cooling containers 5 of (1) to (4) above, the heat-insulating container 35 covers all the outer surfaces of the hollow container 20.

[0027] Therefore, it is possible to gently increase the temperature of the sample 30 and the coolant 33 while imaging the X-ray image 60 of the sample 30. It is possible to extend the time for imaging the X-ray image 60 of the sample 30 at a low temperature lower than room temperature. It is possible to improve the sharpness of the X-ray image 60 of the sample 30 at a low temperature lower than room temperature.

[0028] (6) In any of the cooling containers 5 of (1) to (5) above, the heat insulating container 35 includes a first heat insulating member 36 in contact with the bottom plate 21 and a second heat insulating member 38 in contact with the pipe 22 and the first heat insulating member 36.

[0029] Therefore, the hollow container 20 can be easily accommodated in the heat insulating container 35. The cooling container 5 can be easily incorporated into the X-ray imaging apparatus 2 without modifying the X-ray imaging apparatus 2.

[0030] (7) In the cooling container 5 of (6) above, a recess 37 is formed in the first heat insulating member 36. The second heat insulating member 38 is fitted into the recess 37.

[0031] Therefore, the hollow container 20 can be easily accommodated in the heat insulating container 35. The cooling container 5 can be easily incorporated into the X-ray imaging apparatus 2 without modifying the X-ray imaging apparatus 2.

[0032] (8) In any of the cooling containers 5 of (1) to (7) above, the pipe 22 is formed of a fluororesin or a polyethylene resin.

[0033] Therefore, the pipe 22 is formed of a low-density material that does not embrittle even when cooled by the coolant 33. It is possible to more easily obtain the X-ray image 60 of the sample 30 having a larger size at a low temperature lower than room temperature.

[0034] (9) In the cooling container 5 of (8) above, the pipe 22 is formed of polytetrafluoroethylene or perfluoroalkoxyalkane.

[0035] Therefore, the tube 22 is made of a low-density material that does not embrittle even when cooled by the coolant 33. An X-ray image 60 of a sample 30 having a larger size at a low temperature lower than room temperature can be obtained more easily.

[0036] (10) In any of the cooling containers 5 according to (1) to (9) above, the heat-insulating container 35 is made of styrofoam.

[0037] The heat-insulating container 35 is made of an inexpensive material. The cost of the cooling container 5 can be reduced.

[0038] (11) In any of the cooling containers 5 according to (1) to (10) above, the coolant 33 is a mixture of dry ice and alcohol.

[0039] Using an inexpensive coolant 33, the sample 30 can be maintained at a low temperature lower than room temperature. An X-ray image 60 of a sample 30 having a larger size at a low temperature lower than room temperature can be obtained more easily.

[0040] (12) In any of the cooling containers 5 according to (1) to (11) above, the hollow container 20 further includes a fixing member 25. The sample 30 is supported with respect to the tube 22 via the fixing member 25. The fixing member 25 is provided with a second opening 27 that extends along the longitudinal direction of the tube 22 and penetrates the fixing member 25.

[0041] Therefore, the fixing member 25 enables a sample 30 having a larger size to be supported more stably. An X-ray image 60 of a sample 30 having a larger size at a low temperature lower than room temperature can be obtained more easily.

[0042] (13) The X-ray apparatus 1 of the present disclosure includes an X-ray imaging apparatus 2 and any of the cooling containers 5 according to (1) to (11) above. The X-ray imaging apparatus 2 includes an X-ray source 3 that emits X-rays, a stage 4 that supports the cooling container 5, and an X-ray detector 7 that detects X-rays that have passed through the cooling container 5.

[0043] In the X-ray apparatus 1 of the present disclosure, the sample 30 is cooled using the cooling container 5 of the present disclosure. Therefore, an X-ray image 60 of the sample 30 having a larger size at a low temperature lower than room temperature can be obtained more easily. The X-ray imaging apparatus 2 can be used without modifying the X-ray imaging apparatus 2.

[0044] (14) In the X-ray apparatus 1 of (13) above, the stage 4 is rotatable about the central axis 5c of the cooling container 5 extending along the longitudinal direction of the tube 22 and is movable along the longitudinal direction of the tube 22.

[0045] Therefore, the X-ray apparatus 1 can more easily obtain an X-ray CT image of the sample 30 having a larger size.

[0046] (15) The X-ray image processing apparatus (terminal apparatus 200) of the present disclosure includes an X-ray image reception unit 220 and an image processing unit 221. The X-ray image reception unit 220 receives an X-ray image 60 of the sample 30 acquired by imaging the sample 30 at a low temperature lower than room temperature for a first time. The image processing unit 221 inputs the X-ray image 60 of the sample 30 into a neural network (trained model 113) to generate a corrected X-ray image 66 of the sample 30 that is clearer than the X-ray image 60 of the sample 30. The neural network is generated by training using a training dataset 115. The training dataset 115 includes a first reference X-ray image 61 acquired by imaging the reference sample 31 for a second time without cooling the reference sample 31 and a second reference X-ray image 62 acquired by imaging the reference sample 31 for a third time without cooling the reference sample 31. The second time is 0.5 times or more and 2.0 times or less of the first time. The third time is longer than the first time and longer than the second time.

[0047] While imaging the X-ray image 60 of the sample 30, the temperatures of the sample 30 and the coolant 33 gradually increase. In order to image the X-ray image 60 of the sample 30 at a low temperature lower than room temperature, it is necessary to shorten the first time. When the first time is shortened, the X-ray image 60 of the sample 30 cooled to a low temperature lower than room temperature becomes unclear. The X-ray image processing apparatus of the present disclosure can make the X-ray image 60 of the sample 30 cooled to a low temperature lower than room temperature clearer. The X-ray image processing apparatus of the present disclosure is suitable for the cooling container 5 of the present disclosure in which the X-ray imaging time (the first time) at a low temperature lower than room temperature is shortened.

[0048] (16) The X-ray image processing method of the present disclosure includes a step of acquiring an X-ray image 60 of a sample 30 by imaging the sample 30 for a first time at a low temperature lower than room temperature using the X-ray apparatus 1 of (13) or (14) above (for example, steps S1 to S6), and a step of inputting the X-ray image 60 of the sample 30 into a neural network (trained model 113) to generate a corrected X-ray image 66 of the sample 30 that is clearer than the X-ray image 60 of the sample 30 (step S22). The neural network is generated by learning using a learning dataset 115. The learning dataset 115 includes a first reference X-ray image 61 obtained by imaging the reference sample 31 for a second time using the X-ray apparatus 1 without cooling the reference sample 31, and a second reference X-ray image 62 obtained by imaging the reference sample 31 for a third time using the X-ray apparatus 1 without cooling the reference sample 31. The second time is 0.5 times or more and 2.0 times or less the first time. The third time is longer than the first time and longer than the second time.

[0049] While imaging the X-ray image 60 of the sample 30, the temperatures of the sample 30 and the coolant 33 gradually increase. In order to image the X-ray image 60 of the sample 30 at a low temperature lower than room temperature, it is necessary to shorten the first time. When the first time is shortened, the X-ray image 60 of the sample 30 cooled to a low temperature lower than room temperature becomes unclear. The X-ray image processing method of the present disclosure can make the X-ray image 60 of the sample 30 cooled to a low temperature lower than room temperature clearer. The X-ray image processing method of the present disclosure is suitable for the cooling container 5 of the present disclosure in which the X-ray imaging time (the first time) at a low temperature lower than room temperature is shortened.

[0050] [Details of Embodiments of the Present Disclosure] Next, details of embodiments of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated. At least a part of the configurations of the embodiments described below may be arbitrarily combined.

[0051] <X-ray apparatus 1> The X-ray apparatus 1 is, for example, an X-ray CT (Computed Tomography) apparatus. Referring to FIGS. 1 and 2, the X-ray apparatus 1 includes an X-ray imaging apparatus 2 and a cooling container 5.

[0052] The X-ray imaging apparatus 2 includes an X-ray source 3, a stage 4, and an X-ray detector 7. The X-ray imaging apparatus 2 may further include a stage driving device 6 and a computer 10.

[0053] The X-ray source 3 emits X-rays 3a toward the sample 30. The X-ray source 3 is, for example, an X-ray tube.

[0054] Stage 4 supports the cooling container 5. The cooling container 5 is placed on the sample placement surface 4a. Stage 4 is rotatable about the rotation axis 4r of stage 4. The rotation axis 4r of stage 4 is, for example, an axis extending along the normal line of the sample placement surface 4a. Stage 4 is movable along the normal line (rotation axis 4r of stage 4) of the sample placement surface 4a. When the cooling container 5 is placed on the sample placement surface 4a of stage 4, stage 4 is rotatable about the central axis 5c of the cooling container 5 extending along the longitudinal direction of the tube 22 of the cooling container 5 and is movable along the longitudinal direction (central axis 5c of the cooling container 5) of the tube 22 of the cooling container 5.

[0055] The stage drive device 6 includes a motor (not shown). The stage drive device 6 rotates stage 4 about the rotation axis 4r of stage 4. The stage drive device 6 moves stage 4 along the normal line (rotation axis 4r of stage 4) of the sample placement surface 4a. When the cooling container 5 is placed on the sample placement surface 4a of stage 4, the stage drive device 6 rotates the cooling container 5 about the central axis 5c of the cooling container 5 extending along the longitudinal direction of the tube 22 of the cooling container 5 and moves the cooling container 5 along the longitudinal direction (central axis 5c of the cooling container 5) of the tube 22 of the cooling container 5.

[0056] The X-ray detector 7 detects the X-ray 3a that has passed through the sample 30. When the sample 30 is contained in the cooling container 5, the X-ray detector 7 detects the X-ray 3a that has passed through the sample 30 and the cooling container 5. The X-ray detector 7 may include a plurality of X-ray detection elements 8. Each of the plurality of X-ray detection elements 8 may include a photodiode (not shown) and a scintillator (not shown) provided on the photodiode. The scintillator converts the X-ray 3a into light. The photodiode detects the light converted from the X-ray by the scintillator. By irradiating the sample 30 with the X-ray 3a while rotating the sample 30, an X-ray fluoroscopic image of the sample 30 from all circumferential directions of the sample 30 is captured by the X-ray detector 7.

[0057] The computer 10 includes a processor 11 and a storage 14. The processor 11 is a CPU (Central Processing Unit). The processor 11 realizes the functions of the control unit 12 and the image reconstruction unit 13 by executing a program stored in the storage 14. The control unit 12 controls the X-ray imaging apparatus 2. By the control unit 12 controlling the stage driving device 6, the stage 4 rotates around the rotation axis 4r of the stage 4 and moves along the normal line of the sample placement surface 4a of the stage 4 (the rotation axis 4r of the stage 4). The image reconstruction unit 13 reconstructs the X-ray fluoroscopic image of the sample 30 from all around directions of the sample 30 using a CT reconstruction algorithm such as the back-projection method or the successive approximation method, and generates an X-ray CT image of the sample 30 as the X-ray image 60 of the sample 30.

[0058] The storage 14 may be a non-volatile memory device such as a hard disk or an SSD (Solid State Drive), for example. The X-ray image 60 of the sample 30 is stored in the storage 14.

[0059] <Cooling container 5> Referring to FIGS. 1 to 3, the cooling container 5 is a container for cooling the sample 30. The cooling container 5 has a central axis 5c. When the cooling container 5 is placed on the sample placement surface 4a of the stage 4, the central axis 5c of the cooling container 5 is coaxial with the rotation axis 4r of the stage 4. The cooling container 5 may have an elongated shape in the direction in which the central axis 5c of the cooling container 5 extends. The longitudinal direction of the cooling container 5 may be the direction in which the central axis 5c of the cooling container 5 extends. The cooling container 5 includes a hollow container 20 and a heat insulating container 35.

[0060] The hollow container 20 includes a tube 22 and a bottom plate 21. The hollow container 20 may further include a fixing member 25.

[0061] The tube 22 is formed of a low-density material. In this specification, the low-density material means a material having the following density. The low-density material can transmit X-rays. The X-ray 3a passes through the tube 22. The low-density material has a density of 2.3 g / cm 3 The following density. The low-density material can transmit X-rays. The X-ray 3a passes through the tube 22. The low-density material has a density of 2.3 g / cm 3It may have the following densities. The low-density material may have a density of 0.9 g / cm 3 or more. The low-density material may have a density of 2.0 g / cm 3 or more. The low-density material may have a density of 0.9 g / cm 3 or more and 2.8 g / cm 3 or less. The low-density material may have a density of 2.0 g / cm 3 or more and 2.3 g / cm 3 or less. The tube 22 is formed of a material that does not embrittle even when cooled by the coolant 33. The tube 22 is formed of a material that does not embrittle, for example, at a temperature of -70°C or higher. The tube 22 may be formed of a material that does not embrittle at a temperature of -100°C or higher. The tube 22 is formed of, for example, a fluororesin such as polytetrafluoroethylene (PTFE) or perfluoroalkoxyalkane (PFA), or a polyethylene resin.

[0062] The tube 22 has a cylindrical shape. The tube 22 includes an outer surface 22c and an inner surface 22d on the side opposite to the outer surface 22c. The X-ray 3a passes through the outer surface 22c and the inner surface 22d. The tube 22 includes a first end 22a and a second end 22b on the side opposite to the first end 22a. The outer surface 22c and the inner surface 22d each extend from the first end 22a to the second end 22b. The outer surface 22c has, for example, the shape of a cylindrical outer surface. The inner surface 22d has, for example, the shape of a cylindrical inner surface.

[0063] The bottom plate 21 closes the first end 22a of the tube 22. The accommodation space 22e of the tube 22 is defined by the tube 22 and the bottom plate 21. The bottom plate 21 may be formed of a low-density material. The bottom plate 21 is formed of a material that does not embrittle even when cooled by the coolant 33. The bottom plate 21 is formed of a material that does not embrittle at a temperature of, for example, -70°C or higher. The bottom plate 21 may be formed of a material that does not embrittle at a temperature of -100°C or higher. The bottom plate 21 is formed of, for example, a fluororesin such as polytetrafluoroethylene (PTFE) or perfluoroalkoxy alkane (PFA), or a polyethylene resin. The bottom plate 21 may be formed of the same material as the tube 22. A first opening 23 communicating with the accommodation space 22e is provided at the second end 22b of the tube 22.

[0064] The sample 30 and the coolant 33 are accommodated in the accommodation space 22e. The sample 30 is supported by at least one of the tube 22 and the bottom plate 21. The sample 30 may be supported by both the tube 22 and the bottom plate 21.

[0065] The sample 30 may be supported with respect to the tube 22 via the fixing member 25. The fixing member 25 is in contact with the inner surface 22d of the tube 22. The fixing member 25 may be fitted into the tube 22. A through hole 26 is provided in the fixing member 25. The sample 30 may be fitted into the through hole 26. A second opening 27 is provided in the fixing member 25. The second opening 27 extends along the longitudinal direction of the tube 22 and penetrates the fixing member 25. The fixing member 25 is formed of a low-density material. The fixing member 25 is formed of a material that does not embrittle even when cooled by the coolant 33. The fixing member 25 is formed of a material that does not embrittle at a temperature of, for example, -70°C or higher. The fixing member 25 may be formed of a material that does not embrittle at a temperature of -100°C or higher. The fixing member 25 is formed of, for example, expanded polystyrene. The sample 30 may be supported with respect to the tube 22 via a plurality of fixing members 25. The plurality of fixing members 25 may support, for example, the upper part and the lower part of the sample 30. Therefore, even if the size of the sample 30 is large, the sample 30 is stably supported by the plurality of fixing members 25.

[0066] The sample 30 is immersed in the coolant 33. Specifically, a part of the sample 30 may be immersed in the coolant 33, or the entire sample 30 may be immersed in the coolant 33. The coolant 33 cools the sample 30 to a low temperature lower than room temperature. In this specification, room temperature means a temperature of 15°C or higher and 30°C or lower. The low temperature may be, for example, a temperature lower than 0°C, a temperature lower than -10°C, a temperature lower than -20°C, a temperature lower than -30°C, or a temperature lower than -40°C. The coolant 33 contacts the inner surface 22d of the tube 22. The coolant 33 is, for example, a mixture of dry ice and alcohol (for example, ethanol).

[0067] The heat-insulating container 35 houses the hollow container 20. The heat-insulating container 35c contacts the outer surface 22c of the tube 22. The heat-insulating container 35 may cover all of the outer surface 22c of the tube 22. The heat-insulating container 35 may cover all of the outer surfaces of the hollow container 20. The heat-insulating container 35 may include a first heat-insulating member 36 and a second heat-insulating member 38. The first heat-insulating member 36 contacts the bottom plate 21. A recess 37 may be formed in the first heat-insulating member 36. Specifically, the first heat-insulating member 36 may include a base portion 36a and an annular protruding portion 36b protruding from the base portion 36a. The recess 37 is the inner space of the annular protruding portion 36b. The second heat-insulating member 38 contacts the tube 22 (outer surface 22c) and the first heat-insulating member 36. The second heat-insulating member 38 is fitted into the recess 37.

[0068] The heat-insulating container 35 is formed of a low-density material. Therefore, the heat-insulating container 35 can transmit the X-ray 3a. The X-ray 3a passes through the heat-insulating container 35. The heat-insulating container 35 may be formed of a material that does not embrittle even when cooled by the coolant 33. The heat-insulating container 35 may be formed of a material that does not embrittle at a temperature of -70°C or higher. The heat-insulating container 35 may be formed of a material that does not embrittle at a temperature of -100°C or higher. The heat-insulating container 35 is formed of, for example, styrofoam. The heat-insulating container 35 includes an outer surface 35s. The X-ray 3a passes through a portion of the outer surface 35s that covers the tube 22 (for example, the outer surface of the second heat-insulating member 38). The portion of the outer surface 35s that covers the tube 22 has the shape of a cylindrical outer surface. A through-hole 39 communicating with the first opening 23 is provided in the heat-insulating container 35. The through-hole 39 is provided in, for example, the second heat-insulating member 38.

[0069] The cooling container 5 may not have a temperature adjustment function. Therefore, while the X-ray fluoroscopic image of the sample 30 is being taken, the temperatures of the sample 30 and the coolant 33 gradually rise. A part of the coolant 33 changes into a gas. This gas is discharged to the outside of the cooling container 5 through the second opening 27 of the fixing member 25, the first opening 23 of the tube 22, and the through-hole 39 of the heat-insulating container 35. The second opening 27 of the fixing member 25, the first opening 23 of the tube 22, and the through-hole 39 of the heat-insulating container 35 function as gas vent holes for this gas and prevent the cooling container 5 from being broken by this gas.

[0070] <Method for obtaining the X-ray image 60 of the sample 30> With reference to FIGS. 1 to 4, an example of a method for obtaining the X-ray image 60 of the sample 30 cooled to a low temperature lower than room temperature using the X-ray apparatus 1 will be described. When the X-ray apparatus 1 is an X-ray CT apparatus, the X-ray image 60 of the sample 30 is an X-ray CT image of the sample 30.

[0071] The method for acquiring the X-ray image 60 of the sample 30 according to this embodiment includes putting the sample 30 and the coolant 33 into the cooling container 5 (step S1). The sample 30 is supported by at least one of the tube 22 and the bottom plate 21. The sample 30 may be supported by both the tube 22 and the bottom plate 21. The sample 30 may be supported with respect to the tube 22 via the fixing member 25. The coolant 33 cools the sample 30 to a temperature lower than room temperature.

[0072] The method for acquiring the X-ray image 60 of the sample 30 according to this embodiment includes placing the cooling container 5 on the stage 4 (step S2). Specifically, the cooling container 5 is placed on the sample placement surface 4a of the stage 4. The central axis 5c of the cooling container 5 is coaxial with the rotation axis 4r of the stage 4.

[0073] The method for acquiring the X-ray image 60 of the sample 30 according to this embodiment includes moving the cooling container 5 in the longitudinal direction of the tube 22 (step S3). Specifically, the control unit 12 controls the stage driving device 6. The stage 4 moves along the longitudinal direction of the tube 22. In this way, the part of the sample 30 for which an X-ray fluoroscopic image is desired is positioned on the path of the X-ray 3a.

[0074] The method for acquiring the X-ray image 60 of the sample 30 according to this embodiment includes imaging the X-ray fluoroscopic image of the sample 30 while rotating the cooling container 5 (step S4). Specifically, the control unit 12 controls the stage driving device 6. The stage 4 rotates around the rotation axis 4r of the stage 4 (the central axis 5c of the cooling container 5). The cooling container 5 placed on the sample placement surface 4a of the stage 4 rotates around the central axis 5c of the cooling container 5 (the rotation axis 4r of the stage 4). The sample 30 included in the cooling container 5 rotates around the central axis 5c of the cooling container 5 (the rotation axis 4r of the stage 4). By irradiating the sample 30 with the X-ray 3a while rotating the sample 30, the X-ray fluoroscopic image of the sample 30 from all circumferential directions of the sample 30 is imaged by the X-ray detector 7. The X-ray fluoroscopic image of the sample 30 is stored in the storage 14.

[0075] The method for acquiring the X-ray image 60 of the sample 30 according to this embodiment includes determining whether the imaging of the X-ray fluoroscopic images of all the parts of the sample 30 for which X-ray fluoroscopic images are desired has been completed (step S5). For example, the control unit 12 executes step S5. When the imaging of the X-ray fluoroscopic images of some of all the parts of the sample 30 for which X-ray fluoroscopic images are desired has not been completed (NO in step S5), steps S3 and S4 are performed. In this way, steps S3 and S4 are repeated until the X-ray fluoroscopic images of all the parts of the sample 30 for which X-ray fluoroscopic images are desired are obtained.

[0076] When the imaging of the X-ray fluoroscopic images of all the parts of the sample 30 for which X-ray fluoroscopic images are desired has been completed (YES in step S5), the X-ray fluoroscopic images of the sample 30 are reconstructed to generate an X-ray CT image of the sample 30 as the X-ray image 60 of the sample 30 (step S6). Specifically, the image reconstruction unit 13 reconstructs the X-ray fluoroscopic images of the sample 30 from all around the sample 30 using a CT reconstruction algorithm such as the back-projection method or the successive approximation method to generate an X-ray CT image of the sample 30. The X-ray image 60 of the sample 30 is stored in the storage 14.

[0077] The X-ray image 60 of the sample 30 is acquired by imaging the sample 30 at a low temperature lower than room temperature for a first period of time. In this embodiment, the cooling container 5 does not have a temperature adjustment function. Therefore, during the imaging of the X-ray image 60 of the sample 30, the temperatures of the sample 30 and the cooling liquid 33 gradually increase. In order to image the X-ray image 60 of the sample 30 at a low temperature lower than room temperature, it is necessary to shorten the first period of time. The first period of time is defined by an allowable temperature change ΔT for X-ray imaging of the sample 30 at a low temperature lower than room temperature. The allowable temperature change ΔT may be, for example, 10°C or less, 8°C or less, 5°C or less, 3°C or less, or 1°C or less. When the first period of time becomes shorter, the X-ray image 60 of the sample 30 cooled to a low temperature lower than room temperature becomes unclear.

[0078] Referring to FIG. 5, an example of an X-ray image 60 of the sample 30 is shown. In FIG. 5, the sample 30 is an optical fiber cable including a plurality of optical fibers and a sheath covering the plurality of optical fibers. The X-ray image 60 of the sample 30 is an X-ray CT image of the optical fiber cable obtained by irradiating X-rays over a first period of time at a low temperature of -30°C to -40°C. In the X-ray image 60 of the sample 30 shown in FIG. 5, the white regions are the plurality of optical fibers, and the black background region in the X-ray image 60 of the sample 30 shown in FIG. 5 is the sheath.

[0079] (Modification Example of the Method for Obtaining the X-ray Image 60 of the X-ray Apparatus 1 and the Sample 30) The X-ray apparatus 1 is, for example, an X-ray fluoroscopic imaging apparatus in which the image reconstruction unit 13 is omitted, and the X-ray image 60 may be, for example, an X-ray fluoroscopic image. When obtaining an X-ray fluoroscopic image using the X-ray fluoroscopic imaging apparatus, rotating the cooling container 5 in step S4 and step S6 are omitted from the method for obtaining the X-ray image 60 of the sample 30 shown in FIG. 4.

[0080] (Method for Obtaining a Plurality of First Reference X-ray Images 61 and a Plurality of Second Reference X-ray Images 62) Referring to FIGS. 1, 6, and 7, a plurality of first reference X-ray images 61 are obtained by imaging a plurality of parts of the reference sample 31 over a second time period using the X-ray apparatus 1 without cooling the reference sample 31. Imaging the reference sample 31 using the X-ray apparatus 1 without cooling the reference sample 31 means, for example, imaging an X-ray image of the reference sample 31 in the cooling container 5 without putting the coolant 33 in the cooling container 5 (see FIG. 6), or placing the reference sample 31 on the sample placement surface 4a of the stage 4 without using the cooling container 5 and imaging an X-ray image of the reference sample 31. The second time period is approximately the same as the first time period which is the imaging time of the X-ray image 60 of the sample 30 at a low temperature lower than room temperature. The second time period is, for example, 0.5 times or more and 2.0 times or less the first time period. The plurality of first reference X-ray images 61 may be obtained, for example, by irradiating the reference sample 31 with X-rays 3a over the same second time period as the first time period at room temperature using the X-ray apparatus 1. The reference sample 31 may be different from or the same as the sample 30. The plurality of first reference X-ray images 61 are stored in the storage 14.

[0081] Referring to FIG. 7, an example of the first reference X-ray image 61 is shown. In FIG. 7, the reference sample 31 is an optical fiber cable including a plurality of optical fibers and a sheath covering the plurality of optical fibers. The first reference X-ray image 61 is an X-ray CT image of the optical fiber cable obtained by irradiating X-rays over the same second time period as the first time period at room temperature. Since the second time period is approximately the same as the first time period, the first reference X-ray image 61 is unclear.

[0082] Referring to FIGS. 1, 6, and 8, a plurality of second reference X-ray images 62 are obtained by imaging a plurality of parts of the reference sample 31 over a third time period using the X-ray apparatus 1 without cooling the reference sample 31. The plurality of second reference X-ray images 62 may be obtained, for example, by irradiating the reference sample 31 with X-rays 3a over the third time period at room temperature using the X-ray apparatus 1. The plurality of second reference X-ray images 62 are stored in the storage 14.

[0083] The imaging conditions of the first reference X-ray image 61 and the imaging conditions of the second reference X-ray image 62 mainly differ in the imaging time (the irradiation time of the X-ray 3a on the reference sample 31). That is, the third time, which is the imaging time of the second reference X-ray image 62, is longer than the second time, which is the imaging time of the first reference X-ray image 61. The third time may be, for example, 2 times or more the second time, 2.5 times or more the second time, 4 times or more the second time, 5 times or more the second time, 8 times or more the second time, or 10 times or more the second time. Since the third time is longer than the second time, the second reference X-ray image 62 is clearer than the first reference X-ray image 61.

[0084] Also, the third time, which is the imaging time of the second reference X-ray image 62, is longer than the first time, which is the imaging time of the X-ray image 60 of the sample 30. The third time may be, for example, 4 times or more the first time, 5 times or more the first time, 8 times or more the first time, or 10 times or more the first time.

[0085] Referring to FIG. 8, an example of the second reference X-ray image 62 is shown. In FIG. 8, the reference sample 31 is the optical fiber cable described above. The second reference X-ray image 62 is an X-ray CT image of the optical fiber cable obtained by irradiating X-rays for the third time at room temperature. Since the third time is longer than the second time, the second reference X-ray image 62 is clearer than the first reference X-ray image 61.

[0086] When imaging the second reference X-ray image 62, the temperature of the reference sample 31 is preferably equal to the temperature of the reference sample 31 when imaging the first reference X-ray image 61. However, the temperature of the reference sample 31 when imaging the second reference X-ray image 62 may be different from the temperature of the reference sample 31 when imaging the first reference X-ray image 61. When the temperature of the reference sample 31 when imaging the second reference X-ray image 62 is different from the temperature of the reference sample 31 when imaging the first reference X-ray image 61, the difference between the temperature of the reference sample 31 when imaging a plurality of second reference X-ray images 62 and the temperature of the reference sample 31 when imaging a plurality of first reference X-ray images 61 is smaller than the difference between the temperature of the reference sample 31 when imaging a plurality of first reference X-ray images 61 and the temperature (low temperature) of the sample 30 when imaging the X-ray image 60 of the sample 30. The difference between the temperature of the reference sample 31 when imaging a plurality of second reference X-ray images 62 and the temperature of the reference sample 31 when imaging a plurality of first reference X-ray images 61 may be equal to or less than half, one-third, or one-fourth of the difference between the temperature of the reference sample 31 when imaging a plurality of first reference X-ray images 61 and the temperature (low temperature) of the sample 30 when imaging the X-ray image 60 of the sample 30.

[0087] The difference between the temperature of the reference sample 31 when imaging a plurality of second reference X-ray images 62 and the temperature of the reference sample 31 when imaging a plurality of first reference X-ray images 61 may be, for example, 5°C or less, 3°C or less, or 1°C or less. The difference between the temperature of the reference sample 31 when imaging a plurality of first reference X-ray images 61 and the temperature (low temperature) of the sample 30 when imaging the X-ray image 60 of the sample 30 may be, for example, 10°C or more, 20°C or more, 30°C or more, or 40°C or more.

[0088] The reference image ID (not shown) assigned according to each part of the reference sample 31 is stored in the storage 14 together with the first reference X-ray image 61 and the second reference X-ray image 62 corresponding to each part of the reference sample 31.

[0089] <Image processing system 90> As described above, while the X-ray image 60 of the sample 30 is being captured, the temperatures of the sample 30 and the cooling liquid 33 gradually increase. In order to capture the X-ray image 60 of the sample 30 at a low temperature lower than room temperature, it is necessary to shorten the first time for capturing the X-ray image 60 of the sample 30. Therefore, the X-ray image 60 of the sample 30 cooled to a low temperature lower than room temperature becomes unclear. Thus, image processing for clarifying the X-ray image 60 of the sample 30 cooled to a low temperature lower than room temperature is required. The image processing for clarifying the X-ray image 60 of the sample 30 is, for example, super-resolution processing for improving the resolution of the X-ray image 60 of the sample 30. Referring to FIG. 9, an image processing system 90 for clarifying the X-ray image 60 of the sample 30 cooled to a low temperature lower than room temperature will be described.

[0090] The image processing system 90 includes a server device 100 and a terminal device 200. The image processing system 90 is connected to the computer 10 of the X-ray apparatus 1 (see FIG. 1) via a communication network 50 such as the Internet.

[0091] (Server device 100) The server device 100 acquires a reference image ID (not shown), a plurality of first reference X-ray images 61, and a plurality of second reference X-ray images 62 from the computer 10 of the X-ray apparatus 1 (see FIG. 1) via the communication network 50.

[0092] The server device 100 generates a learned model 113 for performing image processing for clarifying the X-ray image 60 of the sample 30 by a learning process using the first reference X-ray image 61 and the second reference X-ray image 62. The generated learned model 113 is stored in a storage 110 (see FIG. 10) and transmitted (distributed) to the terminal device 200.

[0093] (Terminal device 200) The terminal device 200 acquires the learned model 113 from the server device 100 via the communication network 50. The learned model 113 is stored in the storage 210 (see FIG. 11). The terminal device 200 acquires the X-ray image 60 of the sample 30 from the computer 10 of the X-ray device 1. The X-ray image 60 of the sample 30 is stored in the storage 210. The terminal device 200 inputs the X-ray image 60 of the sample 30 into the learned model 113. The X-ray image 60 of the sample 30 is processed by the learned model 113. The learned model 113 outputs a corrected X-ray image 66 (see FIGS. 11 and 17) of the sample 30 that is clearer than the X-ray image 60 of the sample 30. The corrected X-ray image 66 of the sample 30 is stored in the storage 210 or displayed on the display 204 (see FIG. 11).

[0094] <Hardware Configuration> (Server Device 100) Referring to FIG. 10, the server device 100 includes an input device 101, a processor 102, a memory 103, a display 104, a network controller 106, a storage medium drive 107, and a storage 110.

[0095] The input device 101 accepts various input operations. The input device 101 is, for example, a keyboard, a mouse, or a touch panel.

[0096] The display 104 displays information necessary for processing in the server device 100. The display 104 may display, for example, a first reference X-ray image 61, a second reference X-ray image 62, and a provisional corrected X-ray image 65. The display 104 is, for example, an LCD (Liquid Crystal Display) or an organic EL (Electroluminescence) display.

[0097] The processor 102 executes the processes necessary for realizing the functions of the server device 100 by executing the programs described below. The processor 102 is composed of, for example, one or more CPUs or GPUs (Graphics Processing Units). A CPU or GPU having multiple cores may be used as the processor 102. In the server device 100, it is preferable to adopt a GPU or the like suitable for the learning process for generating the learned model 113.

[0098] The memory 103 provides a storage area for temporarily storing program codes or work memories when the processor 102 executes programs including the data preprocessing program 111 and the learning program 112. The memory 103 is a volatile memory device such as a DRAM (Dynamic Random Access Memory) or an SRAM (Static Random Access Memory), for example.

[0099] The network controller 106 transmits and receives programs or data to and from any device including the X-ray device 1 and the terminal device 200 via the communication network 50 (see FIG. 9). For example, the network controller 106 receives data such as a reference image ID (not shown), a plurality of first reference X-ray images 61, and a plurality of second reference X-ray images 62 from the X-ray device 1 via the communication network 50. The network controller 106 transmits the learned model 113 to the terminal device 200 via the communication network 50. The network controller 106 supports any communication method such as Ethernet (registered trademark), wireless LAN (Local Area Network), or Bluetooth (registered trademark), for example.

[0100] The memory medium drive 107 is a device that reads programs or data stored in the memory medium 108. The memory medium drive 107 may further be a device that writes programs or data to the memory medium 108. The memory medium 108 is a non-transitory memory medium and stores programs or data non-volatilely. The memory medium 108 is, for example, an optical memory medium such as an optical disk (e.g., CD-ROM or DVD-ROM), a semiconductor memory medium such as a flash memory or a USB (Universal Serial Bus) memory, a magnetic memory medium such as a hard disk, an FD (Flexible Disk) or a storage tape, or a magneto-optical memory medium such as an MO (Magneto-Optical) disk.

[0101] The storage 110 stores a program (including, for example, a data preprocessing program 111 and a learning program 112, etc.) executed in the processor 102, a reference image ID (not shown), a plurality of first reference X-ray images 61, a plurality of second reference X-ray images 62, a learned model 113, and a learning dataset 115. The data preprocessing program 111 is a program for generating the learning dataset 115. The learning program 112 is a program for generating the learned model 113 using the learning dataset 115. The storage 110 is, for example, a non-volatile memory device such as a hard disk or an SSD.

[0102] Programs for realizing the functions of the server device 100, including the data preprocessing program 111 and the learning program 112, etc., may be stored in a non-transitory memory medium, distributed, and installed in the storage 110. Programs for realizing the functions of the server device 100 may be downloaded to the server device 100 via the Internet or an intranet.

[0103] In this embodiment, an example is shown in which a general-purpose computer (processor 102) realizes the functions of the server device 100 by executing programs including a data preprocessing program 111, a learning program 112, and the like. However, the present invention is not limited to this, and all or part of the functions of the server device 100 may be realized using an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array).

[0104] (Terminal device 200) Referring to FIG. 11, the terminal device 200 includes an input device 201, a processor 202, a memory 203, a display 204, a network controller 206, a storage medium drive 207, and a storage 210.

[0105] The input device 201 receives various input operations. The input device 201 is, for example, a keyboard, a mouse, or a touch panel.

[0106] The display 204 displays information necessary for processing in the terminal device 200. The display 204 displays, for example, the corrected X-ray image 66 of the sample 30. The display 204 is, for example, an LCD (Liquid Crystal Display) or an organic EL (Electroluminescence) display.

[0107] The processor 202 executes processes necessary for realizing the functions of the terminal device 200 by executing programs described later. The processor 202 is composed of, for example, one or more CPUs or GPUs. A CPU or GPU having a plurality of cores may be used as the processor 202.

[0108] Memory 203 provides a storage area for temporarily storing program code, working memory, etc. when the processor 202 executes a program. Memory 203 is, for example, a volatile memory device such as DRAM or SRAM.

[0109] The network controller 206 transmits and receives programs or data to and from any device including the X-ray apparatus 1 and the server apparatus 100 via a communication network 50 (see FIG. 9). For example, the network controller 206 receives data such as an X-ray image 60 of the sample 30 from the X-ray apparatus 1 via the communication network 50. The network controller 206 receives the learned model 113 from the server apparatus 100 via the communication network 50. The network controller 206 is compatible with any communication method such as, for example, Ethernet (registered trademark), wireless LAN, or Bluetooth (registered trademark).

[0110] The storage medium drive 207 is a device that reads programs or data stored in the storage medium 208. The storage medium drive 207 may further be a device that writes programs or data to the storage medium 208. The storage medium 208 is a non-transitory storage medium that stores programs or data non-volatilely. The storage medium 208 is, for example, an optical storage medium such as an optical disk (e.g., CD-ROM or DVD-ROM), a semiconductor storage medium such as a flash memory or a USB memory, a magnetic storage medium such as a hard disk, an FD, or a storage tape, or a magneto-optical storage medium such as an MO disk.

[0111] Storage 210 stores a program (including, for example, image processing program 211, etc.) executed in processor 202, a learned model 113, an X-ray image 60 of sample 30, and a corrected X-ray image 66 of sample 30. Image processing program 211 is a program for inputting the X-ray image 60 of sample 30 into the learned model 113 to generate the corrected X-ray image 66 of sample 30. Storage 210 is, for example, a non-volatile memory device such as a hard disk or an SSD.

[0112] A program for realizing the functions of terminal device 200, including image processing program 211, etc., may be stored in a non-transitory storage medium for distribution and installed in storage 210. The program for realizing the functions of terminal device 200 may be downloaded to terminal device 200 via the Internet or an intranet.

[0113] In the present embodiment, an example is shown where a general-purpose computer (processor 202) realizes the functions of terminal device 200 by executing a program including image processing program 211, etc., but it is not limited thereto, and all or part of the functions of terminal device 200 may be realized using an integrated circuit such as an ASIC or an FPGA.

[0114] <Generation of Learned Model 113> With reference to FIGS. 9 and 12 to 16, the learning process (method for generating learned model 113) of the present embodiment will be described. The learning process of the present embodiment is executed, for example, by server device 100. Server device 100 functions as a learned model generation device.

[0115] Referring to FIG. 12, the server device 100 includes a reference X-ray image reception unit 120, a data preprocessing unit 121, a learning unit 122, and an output unit 127. The learning unit 122 includes a learning model 123 and a learning program 125. The learning model 123 is composed of a neural network structure 123N and parameters 123P. The neural network structure 123N is a neural network structure classified as a deep neural network (DNN), and includes, for example, a convolutional neural network (CNN) structure. The neural network structure 123N may include a plurality of convolutional layers. The neural network structure 123N is pre-constructed and stored in the server device 100 (storage 110).

[0116] The reference X-ray image reception unit 120 receives a reference image ID, a plurality of first reference X-ray images 61, and a plurality of second reference X-ray images 62 from the X-ray device 1. The reference X-ray image reception unit 120 stores the reference image ID, the plurality of first reference X-ray images 61, and the plurality of second reference X-ray images 62 in the storage 110.

[0117] The data preprocessing unit 121 reads out the reference image ID, the plurality of first reference X-ray images 61, and the plurality of second reference X-ray images 62 from the storage 110. The data preprocessing unit 121 generates a learning dataset 115 by associating the reference image ID, the first reference X-ray image 61 corresponding to the reference image ID among the plurality of first reference X-ray images 61, and the second reference X-ray image 62 corresponding to the reference image ID among the plurality of second reference X-ray images 62 with each other. As shown in FIG. 13, the learning dataset 115 includes a plurality of data sets (learning data 116). Each of the plurality of data sets (each of the learning data 116) includes a reference image ID, a first reference X-ray image 61 corresponding to the reference image ID, and a second reference X-ray image 62 corresponding to the reference image ID. In order to improve the learning accuracy of the learning model 123, the data preprocessing unit 121 may upscale the plurality of first reference X-ray images 61 and the plurality of second reference X-ray images 62 to a desired size using, for example, bicubic interpolation.

[0118] Referring to FIGS. 12 and 14, the learning unit 122 generates a learned model 113. The learning unit 122 updates the values of the parameters 123P of the learning model 123 by machine learning using the learning dataset 115.

[0119] Specifically, the learning unit 122 updates the values of the parameters 123P by using the learning program 125. The learning program 125 inputs the first reference X-ray image 61 of the learning dataset 115 into the learning model 123. The learning model 123 outputs a provisional corrected X-ray image 65. Referring to FIG. 15, an example of the provisional corrected X-ray image 65 is shown. In FIG. 15, the reference sample 31 is the optical fiber cable described above. The learning program 125 repeatedly updates and optimizes the parameters 123P so as to minimize the error between the provisional corrected X-ray image 65 and the corresponding second reference X-ray image 62. Specifically, the parameters 123P of the learning model 123 are repeatedly updated and optimized so as to minimize the error between the provisional corrected X-ray image 65 obtained by inputting the first reference X-ray image 61 with the reference image ID of "1" into the learning model 123 and the second reference X-ray image 62 with the reference image ID of "1". Similarly for each of the other reference image IDs, the parameters 123P of the learning model 123 are repeatedly updated and optimized so as to minimize the error between the provisional corrected X-ray image 65 and the corresponding second reference X-ray image 62. When the learning of the learning model 123 is completed, the learned model 113 is generated.

[0120] Referring to FIG. 17, the learned model 113 has a neural network structure 113N and learned parameters 113P. The neural network structure 113N is a neural network structure classified as a deep neural network (DNN), and includes, for example, a convolutional neural network (CNN) structure. The neural network structure 113N may include a plurality of convolutional layers. The learned parameters 113P are the parameters 123P for which the update has been completed.

[0121] Referring to FIG. 12, the output unit 127 outputs the learned model 113. Specifically, the output unit 127 stores the learned model 113 in the storage 110. The output unit 127 transmits the learned model 113 stored in the storage 110 to the terminal device 200 through the network controller 206.

[0122] Referring to FIG. 16, the learning processing method of the present embodiment will be described. The learning processing method of the present embodiment is executed, for example, in the server device 100. Each step shown in FIG. 16 is realized, for example, by the processor 102 of the server device 100 executing a program including the data preprocessing program 111 (see FIG. 10) and the learning program 112 (see FIG. 10).

[0123] The learning processing method of the present embodiment includes receiving, from the X-ray apparatus 1, a reference image ID, a plurality of first reference X-ray images 61, and a plurality of second reference X-ray images 62 (step S11). The reference X-ray image receiving unit 120 (see FIG. 12) executes step S11. The reference X-ray image receiving unit 120 stores the reference image ID, the plurality of first reference X-ray images 61, and the plurality of second reference X-ray images 62 in the storage 110.

[0124] The learning processing method of the present embodiment includes generating a learning dataset 115 (step S12). The learning dataset 115 is generated by associating a reference image ID, a first reference X-ray image 61 corresponding to the reference image ID among a plurality of first reference X-ray images 61, and a second reference X-ray image 62 corresponding to the reference image ID among a plurality of second reference X-ray images 62 with each other. The data preprocessing unit 121 (see FIG. 12) reads out the reference image ID, the plurality of first reference X-ray images 61, and the plurality of second reference X-ray images 62 stored in the storage 110 and executes step S12. In order to improve the learning accuracy of the learning model 123, the data preprocessing unit 121 may upscale the plurality of first reference X-ray images 61 and the plurality of second reference X-ray images 62 to a desired size using, for example, bicubic interpolation. The data preprocessing unit 121 stores the learning dataset 115 in the storage 110.

[0125] The learning processing method of the present embodiment includes inputting the learning dataset 115 into the learning model 123 to generate a learned model 113 (step S13). The learning unit 122 (see FIG. 12) executes step S13. Specifically, step S13 includes step S14 and step S15. In step S14, the first reference X-ray image 61 included in the learning dataset 115 is input into the learning model 123 to generate a provisional corrected X-ray image 65. In step S14, the parameters 123P of the learning model 123 are repeatedly updated and optimized so as to minimize the error between the provisional corrected X-ray image 65 and the corresponding second reference X-ray image 62. For example, the parameters 123P of the learning model 123 are repeatedly updated and optimized so as to minimize the error between the provisional corrected X-ray image 65 obtained by inputting the first reference X-ray image 61 with the reference image ID of "1" into the learning model 123 and the second reference X-ray image 62 with the reference image ID of "1". Similarly for each of the other reference image IDs, the parameters 123P of the learning model 123 are repeatedly updated and optimized so as to minimize the error between the provisional corrected X-ray image 65 and the corresponding second reference X-ray image 62. In this way, the learned model 113 is generated from the learning model 123.

[0126] The learning processing method of this embodiment includes outputting the learned model 113 (step S16). The output unit 127 (see FIG. 12) executes step S16. Step S16 includes, for example, step S17 and step S18. In step S17, the output unit 127 stores the learned model 113 in the storage 210. In step S18, the output unit 127 transmits the learned model 113 to the terminal device 200. Specifically, the output unit 127 reads the learned model 113 from the storage 210 and transmits the learned model 113 to the terminal device 200 through the network controller 206. The learned model 113 is stored in the storage 210 (see FIG. 11). Thus, the learning processing method of this embodiment is completed.

[0127] <Image processing using the learned model 113> Referring to FIGS. 9 and 17 to 19, the image processing of this embodiment using the learned model 113 will be described. The image processing of this embodiment is executed, for example, by the terminal device 200. The terminal device 200 functions as an X-ray image processing device.

[0128] As shown in FIG. 17, the terminal device 200 includes an X-ray image reception unit 220, an image processing unit 221, and an output unit 227. The image processing unit 221 includes the learned model 113.

[0129] The X-ray image reception unit 220 receives the X-ray image 60 of the sample 30 from the X-ray device 1. The X-ray image reception unit 220 stores the X-ray image 60 of the sample 30 in the storage 210.

[0130] The image processing unit 221 inputs the X-ray image 60 of the sample 30 into the learned model 113 to generate a corrected X-ray image 66 of the sample 30. The learned model 113 is learned by a first reference X-ray image 61 captured over a second time period that is approximately the same length as the first time period, and a second reference X-ray image 62 captured over a third time period that is longer than the first and second time periods. Therefore, the sharpness of the corrected X-ray image 66 of the sample 30 is improved compared to the sharpness of the X-ray image 60 of the sample 30. For example, the corrected X-ray image 66 of the sample 30 has a sharpness comparable to that of the second reference X-ray image 62. The corrected X-ray image 66 of the sample 30 has a sharpness comparable to that of the X-ray image 60 of the sample 30 obtained by imaging the sample 30 over the third time period, which is the imaging time of the second reference X-ray image 62, at a low temperature lower than room temperature. Referring to FIG. 18, an example of the corrected X-ray image 66 is shown. In FIG. 18, the sample 30 is the above-described optical fiber cable.

[0131] The output unit 227 outputs the corrected X-ray image 66 of the sample 30. For example, the output unit 227 stores the corrected X-ray image 66 of the sample 30 in the storage 210. The output unit 227 displays the corrected X-ray image 66 of the sample 30 on the display 204 (see FIG. 11).

[0132] Referring to FIG. 19, the X-ray image processing method of the present embodiment will be described. The X-ray image processing method of the present embodiment is executed, for example, in the terminal device 200. Each step shown in FIG. 19 is realized, for example, by the processor 202 of the terminal device 200 executing a program including the image processing program 211 (see FIG. 11).

[0133] The X-ray image processing method of the present embodiment includes receiving an X-ray image 60 of a sample 30 from the X-ray apparatus 1 (step S21). The X-ray image reception unit 220 executes step S21. The X-ray image reception unit 220 stores the X-ray image 60 of the sample 30 in the storage 210.

[0134] The X-ray image processing method of this embodiment includes inputting the X-ray image 60 of the sample 30 into the learned model 113 to generate a corrected X-ray image 66 (step S22). The image processing unit 221 executes step S22. The learned model 113 is learned by a first reference X-ray image 61 captured over a second time period that is approximately the same length as the first time period, and a second reference X-ray image 62 captured over a third time period that is longer than the first time period and the second time period. Therefore, the sharpness of the corrected X-ray image 66 of the sample 30 is improved compared to the sharpness of the X-ray image 60 of the sample 30.

[0135] The X-ray image processing method of this embodiment includes outputting a corrected X-ray image 66 (step S23). Step S23 includes, for example, storing the corrected X-ray image 66 in the storage 210 (step S24) and displaying the corrected X-ray image 66 on the display 204 (step S25). In this way, the X-ray image processing method of this embodiment is completed.

[0136] (Modification Examples of Image Processing System 90 and Image Processing Method) In the image processing system 90 of the first modification example, the server device 100 and the terminal device 200 do not necessarily need to be communicably connected to the X-ray device 1 via the communication network 50. In the image processing system 90 of the first modification example, the reference image ID, the plurality of first reference X-ray images 61, and the plurality of second reference X-ray images 62 may be transferred from the X-ray device 1 (storage 14) to the server device 100 (storage 110) using a non-volatile storage medium. In the image processing system 90 of the first modification example, the X-ray image 60 of the sample 30 obtained by imaging the sample 30 over a first time period at a low temperature lower than room temperature may be transferred from the X-ray device 1 (storage 14) to the terminal device 200 (storage 210) using a non-volatile storage medium.

[0137] The image processing system 90 of the second modification example includes the server device 100. In the server device 100, the learned model 113 is generated, and the image processing for generating the learned model 113 is performed. The image processing method of the second modification example is executed by the server device 100. The image processing system 90 of the third modification example includes the terminal device 200. In the terminal device 200, the learned model 113 is generated, and the image processing for generating the learned model 113 is performed. The image processing method of the third modification example is executed by the terminal device 200.

[0138] The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The scope of the present disclosure is shown not by the above-described embodiments but by the scope of claims, and it is intended that all meanings equivalent to the scope of claims and all modifications within the scope are included.

Description of Reference Numerals

[0139] 1 X-ray apparatus 2 X-ray imaging apparatus 3 X-ray source 3a X-ray 4 Stage 4a Specimen placement surface 4r Rotation axis 5 Cooling container 5c Central axis 6 Stage drive device 7 X-ray detector 8 X-ray detection element 10 Computer 11 Processor 12 Control unit 13 Image reconstruction unit 14 Storage 20 Hollow container 21 Bottom plate 22 Pipe 22a First end 22b Second end 22c Outer surface 22d Inner surface 22e Accommodation space 23 First opening 25 Fixing member 26 Through-hole 27 Second opening 30 Sample 31 Reference sample 33 Cooling liquid 35 Heat-insulating container 35s Outer surface 36 First heat-insulating member 36a Base part 36b Annular protrusion 37 Recess 38 Second heat-insulating member 39 Through-hole 50 Communication network 61 First reference X-ray image 62 Second reference X-ray image 60 X-ray image 65 Provisional corrected X-ray image 66 Corrected X-ray image 90 Image processing system 100 Server device 101 Input device 102 Processor 103 Memory 104 Display 106 Network controller 107 Memory medium drive 108 Memory medium 110 Storage 111 Pretreatment program 112,125 Learning program 113 Learned model 113N,123N Neural network structure 113P Learned parameters 115 Learning dataset 116 Learning data 120 Reference X-ray image reception part 121 Pretreatment part 122 Learning part 123 Learning model 123P Parameters 127,227 Output part 200 Terminal device 201 Input device 202 Processor 203 Memory 204 Display 206 Network Controller 207 Memory Media Drive 208 Memory Media 210 Storage 211 Image Processing Program 220 Reception Unit 221 Image Processing Unit

Claims

1. A cooling container, wherein the cooling container comprises: a hollow container including a tube having a first end and a second end opposite to the first end, and a bottom plate closing the first end; a heat-insulating container housing the hollow container; a sample and a coolant for cooling the sample are housed in a housing space defined by the tube and the bottom plate; the sample is immersed in the coolant and supported by at least one of the tube or the bottom plate; the tube and the heat-insulating container are formed of a material that can transmit X-rays and has a density of 2.8 g / cm3 or less; a first opening communicating with the housing space is provided at the second end; The heat-insulating container is provided with a through hole communicating with the first opening. A cooling container.

2. The tube has a cylindrical shape, The outer surface of the portion of the heat-insulating container covering the tube has the shape of a cylindrical outer surface. The cooling container according to claim 1.

3. The tube is in contact with both the coolant and the heat-insulating container. The cooling container according to claim 1 or claim 2.

4. The heat-insulating container covers all outer surfaces of the tube. The cooling container according to any one of claims 1 to 3.

5. The heat-insulating container covers all outer surfaces of the hollow container. The cooling container according to any one of claims 1 to 4.

6. The heat-insulating container includes a first heat-insulating member in contact with the bottom plate, and a second heat-insulating member in contact with the tube and the first heat-insulating member. The cooling container according to any one of claims 1 to 5.

7. A recess is formed in the first heat-insulating member, The second heat-insulating member is fitted into the recess. The cooling container according to claim 6.

8. The tube is formed of a fluororesin or a polyethylene resin. The cooling container according to any one of claims 1 to 7.

9. The tube is formed of polytetrafluoroethylene or perfluoroalkoxyalkane. The cooling container according to claim 8.

10. The heat-insulating container is formed of expanded polystyrene. The cooling container according to any one of claims 1 to 9.

11. The coolant is a mixture of dry ice and alcohol. The cooling container according to any one of claims 1 to 10.

12. The hollow container further includes a fixing member, The sample is supported with respect to the tube via the fixing member. The cooling container according to any one of claims 1 to 11, wherein the fixing member is provided with a second opening that extends along the longitudinal direction of the tube and penetrates the fixing member.

13. An X-ray imaging apparatus, and the cooling container according to any one of claims 1 to 11, wherein the X-ray imaging apparatus includes an X-ray source that emits X-rays, a stage that supports the cooling container, and an X-ray detector that detects the X-rays that have passed through the cooling container, the X-ray apparatus.

14. The X-ray apparatus according to claim 13, wherein the stage is rotatable about the central axis of the cooling container that extends along the longitudinal direction of the tube and is movable along the longitudinal direction of the tube.

15. A step of acquiring an X-ray image of the sample by imaging the sample at a low temperature lower than room temperature for a first time using the X-ray apparatus according to claim 13 or claim 14, and a step of inputting the X-ray image of the sample into a neural network to generate a corrected X-ray image of the sample that is clearer than the X-ray image of the sample, wherein the neural network is generated by learning using a learning dataset, the learning dataset includes a first reference X-ray image obtained by imaging the reference sample for a second time using the X-ray apparatus without cooling the reference sample, and a second reference X-ray image obtained by imaging the reference sample for a third time using the X-ray apparatus without cooling the reference sample, the second time is 0.5 times or more and 2.0 times or less of the first time, and the third time is longer than the first time and longer than the second time, the X-ray image processing method.

Images