Radiation imaging device, radiation imaging system, radiation image processing device, control method of radiation imaging device, image processing method and program

Abstract

To provide a radiation imaging device for acquiring offset information corresponding to many radiation imaging modes in a shorter time.SOLUTION: A radiation imaging device includes: an image data acquisition unit for acquiring a radiographic image relating to an imaging mode selected from a plurality of imaging modes; an offset correction data acquisition unit for acquiring an offset image corresponding to each of the plurality of imaging modes; an offset correction unit for correcting the radiographic image using the acquired offset correction data; a determination unit for determining a group of imaging modes for which common offset correction data can be used, in the plurality of imaging modes, and selecting an offset image to be used for offset correction from offset images corresponding to each of the imaging modes in the group; and an update unit for updating the selected offset image to a corresponding offset image for the offset correction of the imaging modes in the group.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a radiation imaging apparatus, a radiation imaging system, a radiation image processing apparatus, a control method for a radiation imaging apparatus, an image processing method, and a program. [Background technology]

[0002] Radiation imaging devices and systems that irradiate a subject with radiation from a radiation generating device and obtain a radiation image from the intensity distribution of the radiation that has passed through the subject have been commercialized. These radiation imaging devices and systems digitize the intensity distribution of the radiation and perform image processing on the digitized radiation image to obtain a clear radiation image.

[0003] Here, a radiation image generated by a radiation imaging device includes not only a component corresponding to the incident radiation but also a component corresponding to the dark charge. In order to obtain a suitable radiation image, it is necessary to remove the component corresponding to the dark charge. As a method for removing the component, a technique (offset correction) is known in which an image acquired when the radiation imaging device is not irradiated with radiation (a so-called offset image) is subtracted from the radiation image. The amount of dark charge generated depends on the internal temperature of the radiation imaging device. Therefore, if there is a difference in temperature distribution within the radiation imaging device between when the offset image is acquired and when the radiation image is acquired, the offset component may not be correctly removed. For this reason, when acquiring a radiation image, it is necessary to appropriately acquire or update an offset image used for subtraction.

[0004] Various proposals have been made regarding the acquisition of such offset images or the updating of the offset images. For example, Patent Document 1 describes that when a new offset image is acquired in any one of a plurality of radiation imaging modes, offset information for the other modes is calculated and updated based on the acquired offset image. Patent Document 2 describes that offset images are acquired according to an order and frequency set based on the imaging conditions of a plurality of radiation imaging modes. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2003-190126 A [Patent Document 2] JP 2017-6331 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the method disclosed in Patent Document 1, when there are a large number of multiple radiation imaging modes, it takes time to calculate all offset information of other modes based on the acquired offset image. Therefore, depending on the number of radiation imaging modes, there is a possibility that the period during which imaging cannot be performed due to updating the offset information of all radiation imaging modes may be long. In addition, in the method disclosed in Patent Document 2, the order of acquiring offset images is determined. Therefore, when there are a large number of multiple radiation imaging modes, the offset image of the radiation imaging mode acquired later in the acquisition order is acquired and updated less frequently. As a result, when the time required to acquire offset images is limited, appropriate offset correction may not be performed depending on the radiation imaging mode used, which may significantly affect image quality.

[0007] The present disclosure has been made in consideration of the above circumstances, and has as one object to provide a radiation imaging apparatus that can acquire offset information corresponding to a large number of radiation imaging modes in a shorter time. [Means for solving the problem]

[0008] In order to solve the above problem, a radiation imaging apparatus according to an aspect of the present disclosure includes: an image data acquisition unit that acquires radiation image data according to an imaging mode selected from a plurality of imaging modes for acquiring a plurality of types of radiation images; an offset correction data acquisition unit that acquires offset correction data corresponding to each of the plurality of shooting modes; an offset correction unit that corrects the radiation image data using the acquired offset correction data; a determination unit that determines an imaging mode in which common offset correction data can be used among the plurality of imaging modes, and selects offset correction data that the offset correction unit uses for correction of the determined imaging mode from among the offset correction data corresponding to each of the determined imaging modes; an updating unit that causes the offset correction data acquiring unit to acquire offset correction data corresponding to the selected offset correction data in order to update offset correction data used in the shooting mode in which it is determined that the common offset correction data can be used; Equipped with. Effect of the Invention

[0009] In a radiation imaging device according to an aspect of the present disclosure, offset information corresponding to a large number of radiation imaging modes can be acquired in a shorter time. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a radiation imaging system. [Diagram 2] 2 is a diagram illustrating an example of the configuration of a radiation detection unit in a radiation imaging apparatus. [Diagram 3] 11 is a flowchart for determining offset correction data of a radiation imaging apparatus. [Figure 4] FIG. 4 is a diagram showing imaging mode information of the radiation imaging apparatus. [Diagram 5] 13 is a flowchart of an update process of an offset image of the radiation imaging apparatus. [Figure 6] FIG. 13 is a diagram illustrating an example of the configuration of a radiation image processing device according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, exemplary embodiments for carrying out the present disclosure will be described in detail with reference to the accompanying drawings as examples. However, the dimensions, materials, and relative positions of components described in the following examples are arbitrary and can be changed according to the configuration or various conditions to which the present disclosure is applied. In addition, the same reference numerals are used between the drawings to indicate elements that are identical or functionally similar.

[0012] In the following embodiments, a radiation imaging system using X-rays as an example of radiation will be described, but the radiation imaging system according to the present disclosure may use other radiation. Here, the term radiation includes electromagnetic radiation such as X-rays and gamma rays, as well as particle radiation such as alpha rays, beta rays, particle beams, proton beams, heavy ion beams, and meson beams.

[0013] <Example> Hereinafter, a radiation imaging apparatus, a radiation imaging system, a radiation image processing device, a method for controlling a radiation imaging apparatus, and an image processing method according to the embodiments of the present disclosure will be described with reference to Figs. 1 to 5. Fig. 1 shows an example of a configuration of a radiation imaging system 1 according to the present embodiment. The radiation imaging system 1 includes a radiation imaging apparatus 100, a radiation generating apparatus 300, a radiation source 301, a control device 400, and an image control device 500. The radiation imaging apparatus 100 includes a radiation detection unit 200. The radiation generating apparatus 300 controls the radiation source 301 that irradiates radiation. The control device 400 includes a radiation imaging application 404 that controls the radiation imaging apparatus 100 and the radiation generating apparatus 300, and is capable of collecting and displaying captured images from the radiation imaging apparatus 100, receiving imaging orders, and registering imaging information. The image control device 500 outputs captured images output from the radiation imaging apparatus 100 to the control device 400.

[0014] The control device 400 is connected to an intra-hospital network 600, which is, for example, a local area network (LAN). A radiology information system 601, such as a RIS (Radiology Information System) or a hospital information system, such as a HIS (Hospital Information System), is also connected to the intra-hospital network 600. The control device 400 and the HIS / RIS 601 can communicate with each other, enabling the exchange of radiographic image capture orders, capture information including, for example, patient information, and captured image data itself.

[0015] The radiation imaging device 100 includes a radiation detection unit 200 that detects radiation and generates image data, a control unit 101 that controls imaging and communication operations, and a power source 115. The control unit 101 includes a drive control unit 102, an image processing unit 106, an offset image update control unit 108, a storage unit 109, a communication control unit 112, an internal clock 113, and a radiation generation device control unit 114. The drive control unit 102 controls driving of the radiation detection unit 200 and acquisition of radiation images and offset images. The image processing unit 106 performs image processing on the image acquired from the radiation detection unit 200. The offset image update control unit 108 controls the update timing of the offset image. The storage unit 109 stores the acquired image data. The communication control unit 112 controls communication with the control device 400 and communication with the radiation generation device 300. The internal clock 113 acquires the imaging time, elapsed time, and the like. The radiation generating device control unit 114 controls the radiation irradiation timing based on a radiation irradiation signal from the radiation generating device 300.

[0016] The control unit 101, for example, reads out a program or the like stored in the storage unit 109, and based on the program or the like, controls the entire radiation imaging apparatus 100. Note that the control of the radiation imaging apparatus 100 may be performed by a control signal generating circuit such as an ASIC, or may be realized by both the program and a control circuit.

[0017] The radiation generating apparatus 300 has an operation UI (User Interface) 302 for operating the radiation generating apparatus 300. By using the operation UI 302, a user can set radiation irradiation conditions and give instructions related to radiation irradiation. In this embodiment, the radiation generating apparatus 300 and the radiation imaging apparatus 100 are configured to be able to exchange information via a dedicated signal line. Using this dedicated signal line, synchronization signals related to notifications of the start and end of radiation irradiation, notifications of timing when radiation irradiation becomes possible, and the like are exchanged between the radiation generating apparatus 300 and the radiation imaging apparatus 100.

[0018] The control device 400 includes a communication control unit 401, a radiation imaging device control unit 402, a radiation generation device control unit 403, and a power supply 405. The communication control unit 401 controls communication with the radiation imaging device 100, with the radiation generation device 300, and with the hospital LAN. The radiation imaging device control unit 402 controls the image acquisition timing and image acquisition conditions of the radiation imaging device 100. The radiation generation device control unit 403 controls the radiation irradiation conditions of the radiation generation device 300. The power supply 405 functions as the main power supply for the control device 400.

[0019] The control device 400 also includes the above-mentioned radiation imaging application 404 that controls the radiation imaging device 100 and the radiation generation device 300, and is capable of acquiring and displaying captured images from the radiation imaging device 100, accepting imaging orders, and registering imaging information. A display unit 406 for displaying captured images and imaging information, and an operation UI (keyboard, mouse, etc.) 407 for operating the radiation imaging application 404 can be connected to the control device 400.

[0020] Here, information can be exchanged between the control device 400 and the radiation imaging device 100, and between the control device 400 and the radiation generating device 300. This information exchange can be achieved by any one or more of cable connection communication using standards such as RS232C, USB, and Ethernet, dedicated signal lines, and wireless communication. Control communication is performed between the control device 400 and the radiation imaging device 100, such as acquisition of image data, setting of image acquisition conditions, and acquisition of information related to the device status. Control communication is performed between the control device 400 and the radiation generating device 300, such as setting of radiation irradiation conditions, acquisition of information related to the device status, and acquisition of actual irradiation information.

[0021] The image control device 500 performs image processing on the image transferred from the radiation imaging device 100, and transfers the processed image to the control device 400. A display unit 501 is further connected to the image control device 500, and the display unit 501 is used to display the image output from the radiation imaging device 100, for example, when the control device 400 goes down.

[0022] Although the control device 400 and the image control device 500 are illustrated as separate devices, they can be configured as one unit, and each can be configured as a computer provided with a processor and a memory. Moreover, these control devices 400 and 500 can be configured as a general computer, or as a computer dedicated to the radiation imaging system. Furthermore, these control devices 400 and 500 can be integrated with the display unit 406 and the operation UI 407 to form a single PC (Personal Computer).

[0023] Next, the radiation detection unit 200 will be described. Fig. 2 shows an example of the configuration of the radiation detection unit 200. The radiation detection unit 200 has a sensor array 204 consisting of a plurality of pixels arranged in a two-dimensional array to form a plurality of rows and a plurality of columns. Each pixel 207 on the sensor array 204 is composed of a switch element 208, such as a TFT, and a photoelectric conversion element 209. In addition, for example, a phosphor is provided on each pixel 207. Radiation incident on the radiation detection unit 200 is converted into visible light by the phosphor, and the converted visible light is incident on the photoelectric conversion element 209 of each pixel, and an electric charge corresponding to the visible light is generated in each photoelectric conversion element 209.

[0024] In this embodiment, the radiation detection unit 200 is configured as a so-called indirect conversion type in which incident radiation is converted into electric charge by the above-mentioned phosphor and photoelectric conversion element. However, the radiation detection unit 200 may be configured as a so-called direct conversion type in which incident radiation is directly converted into electric charge without providing a phosphor. In the radiation detection unit 200, charge accumulation and readout are carried out by switching the switch element 208 between ON and OFF, thereby making it possible to obtain a radiological image.

[0025] The pixels 207 in each row on the two-dimensional sensor array 204 of the radiation detection unit 200 are connected to a drive circuit 201 via drive lines 211 that are arranged corresponding to each row and connected to each of the pixels 207 in each row. When a TFT ON voltage is applied to the drive line 211 by the drive circuit 201, the switch elements 208 of each pixel 207 in a row are turned ON. As a result, the charges accumulated in the pixels 207 are held in the sample hold circuit 202 through the respective signal lines 210. The held pixel output charges are then sequentially read out via the multiplexer 203, amplified by the amplifier 205, and converted into digital image data by the A / D converter 206.

[0026] Further, for each pixel 207 in a row where charge reading has been completed, a TFT OFF voltage is applied to the corresponding drive line 211 by the drive circuit 201, and the switch element 208 of each pixel 207 in the row is turned OFF. As a result, each pixel 207 in the row to which a bias voltage has been applied by the power supply 212 returns to a state in which it can accumulate charge. In this manner, the drive circuit 201 sequentially drives and scans each row on the sensor array 204, and finally the charges as the output of all the pixels 207 are converted into digital values. This makes it possible to read out radiation image data. The drive and readout operations of these detection units are controlled by the drive control unit 102. The image data converted into digital values ​​is stored in the memory unit 109 in FIG. 1.

[0027] Next, referring to FIG. 1 again, one aspect of the drive control unit 102 in this embodiment will be described. The drive control unit 102 includes an imaging preparation drive control unit 103, a radiation image acquisition control unit 104, an offset image acquisition control unit 105, and a determination unit 120. The imaging preparation drive control unit 103 causes the radiation detection unit 200 to perform preparations so that radiation imaging by the radiation imaging device 100 is possible. The radiation image acquisition control unit 104 causes the radiation detection unit 200 to acquire image data used for generating a radiation image. The offset image acquisition control unit 105 controls switching of the offset image to be acquired when acquiring an offset image. The offset image acquisition control unit 105 also includes a determination unit 120, which is configured to determine which offset image is appropriate to acquire and use in an offset correction process described later.

[0028] The imaging preparation drive control unit 103 applies the same voltage as during imaging to the radiation detection unit 200, periodically reads out charges, and resets the dark charges accumulated in each pixel. The charges read out at this time are not treated as image data, and need not be stored in the storage unit 109. The radiation image acquisition control unit 104 irradiates radiation to each pixel in a state where charges are accumulated, while performing drive control similar to that performed by the imaging preparation drive control unit 103 on the radiation detection unit 200. The radiation image acquisition control unit 104 reads out image data accumulated in the radiation detection unit 200 by radiation irradiation, and stores this as a radiation image in the radiation image storage unit 110 of the storage unit 109. Continuously performing drive control of the radiation detection unit 200 by the radiation image acquisition control unit 104 makes it possible to capture a radiation image as a moving image.

[0029] The offset image acquisition control unit 105 also reads image data from the radiation detection unit 200 without irradiating radiation while performing drive control similar to that performed by the imaging preparation drive control unit 103 on the radiation detection unit 200. The read image data is held in the offset image storage unit 111 of the storage unit 109 as an offset image.

[0030] For the radiographic image acquired from the radiation detection unit 200 during imaging, an offset correction process is performed by the offset correction unit 107 of the image processing unit 106 using an offset image previously acquired during non-imaging. The radiographic image that has undergone the offset correction process is transferred to the image control device 500 via the communication control unit 112. Note that, although only the offset correction process has been described here, correction processes such as correction of defective pixels and gain correction for correcting gain variations of amplifiers in the radiation detection unit may also be performed.

[0031] Furthermore, these correction processes are not limited to being performed in the radiation imaging device 100. For example, the acquired radiation image and offset image may be transferred to the image control device 500 without correction, and the correction process may be performed within the image control device 500. Furthermore, the offset image used in the offset correction process may be an image that has been subjected to a process of reducing noise components by averaging a plurality of acquired offset images, for example.

[0032] In this embodiment, offset correction is performed on a radiographic image acquired under the control of the radiographic image acquisition control unit 104, using an offset image acquired by the offset image acquisition control unit 105. However, the target for offset correction is not limited to an image. For example, it may be digital data before image generation, or data obtained by subjecting the digital data to processing such as the gain correction described above. These data may be collectively referred to as image data and offset correction data.

[0033] As imaging modes used when capturing a radiation image, a plurality of imaging modes, for example, different frame rates, are prepared in advance. Usually, a plurality of offset images are acquired corresponding to each of the plurality of imaging modes, and offset correction processing is performed using the offset images corresponding to the imaging modes. In the present disclosure, for example, when the frame rates are relatively close, these are grouped into one image group, and the offset images used for offset correction processing for the images in the image group are made common. This reduces the number of offset images to be acquired before performing radiation imaging, making it possible to acquire the required number of offset images in a shorter time than before.

[0034] A process for selecting offset images that can be shared will be described below with reference to Fig. 3. Fig. 3 is a flow chart showing an example of a process for determining whether offset images acquired in individual imaging modes can be shared in common in the radiation imaging apparatus 100. The determination flow shown in Fig. 3 is executed, for example, when the radiation imaging apparatus 100 is started up or when radiation imaging is performed after a long period of non-use.

[0035] For example, when the radiation imaging apparatus 100 is started, a determination flow is started by the drive control unit 102. Note that the relationship between the imaging modes used in the following description and the frame rates in the imaging modes is shown in Fig. 4. However, the imaging conditions that can be changed for each imaging mode are not limited to the frame rate, and all imaging conditions set in the imaging modes used in normal radiation imaging can be targets.

[0036] When the determination flow starts, in step S301, the offset image update control unit 108 executes a process of acquiring offset images in all shooting modes shown in Fig. 4. Then, the acquired offset images are stored in the offset image storage unit 111 of the storage unit 109. That is, for all mode numbers shown in Fig. 4, acquisition and storage of offset images is started from mode number 1 in descending order of frame rate, and acquisition and storage of offset images is executed in the order of mode number 2, mode number 3, and up to mode number 11. When the process of acquiring offset images in all shooting modes ends, the drive control unit 102 transitions the flow to step S302.

[0037] In step S302, the determination unit 120 executes a process of determining which offset images can be shared. As a specific example of the determination process, the determination unit 120 calculates an average value of all pixels from the offset images for each mode stored in the offset image storage unit 111 in step S301. For example, if the difference between the average values ​​of all pixels for each mode is within ±3, the values ​​of each pixel in the offset images are close to each other, and it is considered that the same offset image can be used for offset correction processing even in different shooting modes. Therefore, it can be determined that the offset correction image to be used can be shared even in different shooting modes.

[0038] Here, when the frame rate is low, the accumulation time of each pixel becomes long, and the dark current component increases. When the frame rate is close, the accumulation time of each pixel is close, and the average value of each pixel becomes close. In view of this, the frame rate can also be used as a judgment criterion. In the example shown in FIG. 4, it is judged that the offset correction image can be shared for each of the three groups of shooting modes, mode numbers 1 to 4, mode numbers 5 to 8, and mode numbers 9 to 11. When the offset image that can be shared is judged, the drive control unit 102 moves the flow to step S303.

[0039] In step S303, the offset image update control unit 108 selects a shooting mode for the offset image to be acquired next. Specifically, one representative shooting mode is determined from the three groups determined to be common in step S302. In this case, for example, a shooting mode with the highest frame rate can be selected as the representative mode in order to shorten the acquisition time of the offset image. In this case, the shooting modes selected are mode numbers 1, 5, and 9. Therefore, the shooting conditions of mode numbers 1, 5, and 9 become the acquisition conditions of the offset image to be acquired next. When the acquisition conditions of the offset image to be acquired next are determined, the determination flow ends.

[0040] In this embodiment, in step S302, the shooting mode capable of commonalization of the offset images is determined based on the average value of all pixels of the offset images. However, the conditions for the determination are not limited to those in the embodiment, and the determination may be performed based on the average value of all pixels, the amount of noise, and the in-plane distribution. In this case, as an example of the amount of noise, if the difference in the amount of noise for each mode is small, it can be determined that the shooting mode is capable of commonalization of the offset images. Specifically, the standard deviation (σ) of the pixel values ​​of all pixels of the offset images in each shooting mode is calculated, and if the difference in σ is, for example, ±5 or less, it can be determined that the shooting mode is capable of commonalization. In addition, as an example of the in-plane distribution, the difference between the maximum and minimum pixel values ​​in the horizontal or vertical direction passing through the image center of the offset images in each shooting mode is used, and it can be determined that the shooting mode is capable of commonalization for the shooting modes in which this difference is small. Specifically, if the difference (Δ) between the maximum and minimum pixel values ​​in the vertical direction passing through the image center is, for example, ±15 or less in each mode, it can be determined that the shooting mode is capable of commonalization. Furthermore, these conditions for determination may be used individually or in combination.

[0041] In this embodiment, in step S303, the imaging mode with the highest frame rate is selected as the representative mode. However, the method of selecting the representative mode is not limited to the embodiment. For example, the imaging mode with the least amount of noise can be selected as the representative mode, or the imaging mode with the frame rate closest to the median value in the group can be selected as the representative mode. In addition, if the minimum pixel value in the radiation image is smaller than the minimum pixel value in the offset image, the pixel value may become negative by subtraction in the offset correction process. In such a case, the mode with the smallest average value of all pixels may be selected as the representative mode.

[0042] Next, the update process of the offset image executed by the offset image update control unit 108 will be described with reference to Fig. 5. Fig. 5 is a flowchart showing the update process of the offset image according to this embodiment. For example, when a command to start capturing a radiographic image is input by the user via the operation UI 407, the update process of the offset image is started by the offset image update control unit 108, and the flow proceeds to step S501. At the same time, the imaging preparation drive control unit 103 executes a preparation operation of the radiation detection unit 200 to make the radiation imaging apparatus 100 ready for radiographic imaging.

[0043] In step S501, the internal clock 113 is used to obtain the elapsed time since the offset image update process was last executed. For example, if the offset image update process to be executed is the first process of the day, and no offset image update has been performed recently, the elapsed time is set to the maximum value. After obtaining the elapsed time, the offset image update control unit 108 causes the flow to proceed to step S502.

[0044] In step S502, the offset image update control unit 108 compares the elapsed time acquired in step S501 with a predetermined elapsed threshold time T. If it is determined that the elapsed time is greater than T, the flow proceeds to step S503, and if the elapsed time is equal to or less than T, the flow returns to step S501. In step S501, the preparation operation by the shooting preparation drive control unit 103 continues, and the process of acquiring the elapsed time is repeated. In this embodiment, T=5 minutes is used as an example of the elapsed threshold time.

[0045] In step S503, the offset image update control unit 108 checks whether the radiation imaging apparatus 100 is performing fluoroscopy or imaging processing. If it is confirmed that the radiation imaging apparatus 100 is not performing fluoroscopy or imaging processing, the flow proceeds to step S504, and if it is confirmed that the radiation imaging apparatus 100 is performing fluoroscopy or imaging processing, the flow returns to step S501. If the radiation imaging apparatus 100 is not performing fluoroscopy or imaging processing, the acquisition of the elapsed time is repeated in step S501.

[0046] In step S504, the preparation operation of the imaging preparation drive control unit 103 is switched to an offset image acquisition process by the offset image acquisition control unit 105, and an offset image update process is executed. Specifically, updates of the offset images of mode numbers 1, 5, and 9 selected in step S303 of Fig. 3 are executed sequentially. For images acquired by the radiographic image imaging process determined to be in progress in step S503, an offset correction process using the offset image updated in step S504 is enabled. After the offset image is updated, the flow moves further and the offset image update process is terminated.

[0047] The offset correction process of the radiographic image acquired from the radiation detection unit 200 will be specifically illustrated with reference to the example of Fig. 4. For example, it is assumed that mode numbers 4 and 1 in the imaging modes are included in an imaging mode group in which a common offset image can be used, and an offset image obtained under the conditions of mode number 1 can be used for offset correction. In this case, when imaging a radiographic image in mode number 4, the offset image of mode number 1 stored in the acquired offset image storage unit 111 is used for the offset correction process of the radiographic image acquired from the radiation detection unit 200. After the offset correction process is performed by the offset correction unit 107 of the image processing unit 106 using the offset image of mode number 1, the corrected radiographic image is transferred to the image control device 500 via the communication control unit 112.

[0048] As described above, in the embodiment according to the present disclosure, offset images that can be commonly used in a plurality of imaging modes are selected, and only the offset images for the minimum number of imaging modes that cannot be shared are updated. Then, for the radiographic images of the imaging modes that are determined to be shareable, only the selected offset images are updated, and offset correction processing is performed using the updated offset images. By performing the offset correction processing in this manner, the time required to update the offset images can be shortened compared to the time required for the conventional manner of updating offset images for all imaging modes. As a result, radiographic imaging using the latest offset information can be performed immediately.

[0049] Note that if the offset image is updated immediately after shooting, there is a possibility that an afterimage may be included in the offset image. For this reason, the time elapsed since the completion of shooting may be measured, and the offset image may be updated only when both the elapsed time from the completion of shooting and the elapsed time from the update process of the offset image are satisfied.

[0050] <Modification> In the above-described embodiment, the determination unit 120 is provided in the radiation imaging device 100. However, the embodiment of the present disclosure is not limited to the embodiment. For example, referring to the example of FIG. 4, when a radiation image is acquired under the condition of mode number 4 by the radiation imaging device 100 of the present disclosure, it is possible that the offset correction image of mode number 4 has not been updated and the most recent appropriate offset correction image has not been stored. In such a case, for example, the image processing unit 106 or the image control device 500 can perform the offset correction process using an offset image of mode number 1 that is not an offset image of mode number 4 but is allowed to be commonly used for both mode number 4 and the offset image. In such a case, the present disclosure can be configured as an image processing device.

[0051] Such an embodiment of the present disclosure will be described below as a modified example with reference to Fig. 6. Fig. 6 is a diagram showing an example of the configuration of a radiological image processing device 6 according to the modified example of the present disclosure. The radiological image processing device 6 shown in Fig. 6 includes a radiological image acquisition control unit 604, an offset image acquisition control unit 605, an offset correction unit 607, and a storage unit 609. The image processing device 6 is connected to a radiological image imaging device 100 or a storage unit 109 that stores an image captured by the radiological image imaging device 100.

[0052] The radiation image acquisition control unit 604 acquires a radiation image from the radiation imaging apparatus 100 or the storage unit 109. The offset image acquisition control unit 605 acquires an offset image from the radiation imaging apparatus 100 or the storage unit 109. The determination unit 620 included in the offset image acquisition control unit 605 can execute the process shown in FIG. 3 in the same manner as the determination unit 120 described in the embodiment. That is, the offset image acquisition control unit 605 determines the imaging modes in which a common offset image can be used for offset processing, and selects the offset image to be used in offset correction of these imaging modes. The offset correction unit 607 performs offset correction on the radiation image acquired by the radiation image acquisition control unit 604, using the offset image acquired by the offset image acquisition control unit 605. The storage unit 609 stores the imaging modes in which the common offset image can be used by the determination unit 620 in association with the selected offset correction image.

[0053] Here, if the most recent offset image corresponding to the acquired radiation image has been acquired, the offset correction unit 607 performs offset correction of the radiation image using this offset image. However, for example, when the offset image acquisition time or the radiation image capture is continuous, it may be impossible to acquire an offset image corresponding to the imaging mode to be acquired. Even in such a case, the selected offset image is updated in the radiation imaging device 100 described as the embodiment. The offset correction unit 607 performs offset correction of the imaging mode in which the common offset image is available, using the offset image updated according to the imaging mode when the selected offset image stored in the storage unit 609 was obtained. By performing such processing, the image processing device according to this modified example can perform offset correction of the acquired radiation image using an appropriate offset image even if there is no offset image corresponding to the imaging mode.

[0054] As described above, the radiation imaging device 100 according to an embodiment of the present disclosure includes an image data acquisition section (radiation image acquisition control section 104) and an offset data acquisition section (offset image acquisition control section 105). The radiation imaging device 100 further includes an offset correction section 107, a determination section 120, and an update section (offset image update control section 108). The radiation image acquisition control section 104 functions as an example of an image data acquisition section that acquires radiation image data (radiation image) related to an imaging mode selected from a plurality of imaging modes for acquiring a plurality of types of radiation images according to the imaging conditions of the selected imaging mode. The offset image acquisition control section 105 functions as an example of an offset data acquisition section that acquires offset correction data (offset image) obtained in the imaging mode in correspondence with each of the plurality of imaging modes. The offset correction section 107 functions as an example of an offset correction section that corrects a radiation image using the acquired offset image. The determination section 120 determines an imaging mode in which a common offset image can be used in the plurality of imaging modes. The determination unit 120 also functions as an example of a determination unit that selects one offset image to be used for correction of the determined imaging mode by the offset correction unit 107 from among the offset images corresponding to each determined imaging mode. The offset image update control unit 108 functions as an example of an update unit that updates one offset to be used for an imaging mode determined by the determination unit 120 to be able to use a common offset image. More specifically, the offset image acquisition control unit 105 is caused to acquire an offset image in the same imaging mode as the imaging mode in which the offset image was obtained so as to correspond to the offset image selected by the determination unit 120. This makes it possible to efficiently obtain the latest offset correction data in a short time, even when there are a large number of radiation imaging modes that can be used, and makes it possible to appropriately perform offset correction.

[0055] In the radiation imaging device 100 described above, the determination unit 120 can determine an imaging mode in which the common offset image can be used based on an average value of pixel values ​​of all pixels of the offset image, which is an average value of offset correction data. Alternatively, the determination unit 120 may determine an imaging mode in which the common offset image can be used based on the noise amount of all pixels of the offset image. Furthermore, the determination unit 120 may determine an imaging mode in which the common offset image can be used based on an in-plane distribution of pixel values ​​of all pixels, which is an in-plane distribution of the offset image.

[0056] The determination unit 120 can select an offset image corresponding to a shooting mode with the maximum frame rate from among the offset images used in the shooting modes determined to be able to use a common offset image. Alternatively, the determination unit 120 may select an offset image corresponding to a shooting mode with the smallest amount of noise from among the offset images used in the shooting modes determined to be able to use a common offset image. The determination unit 120 may also select an offset image corresponding to a shooting mode with the smallest average value of pixel values ​​of all pixels from among the offset images used in the shooting modes determined to be able to use a common offset image.

[0057] The present disclosure can also be applied to a radiation imaging system 1. In this case, the radiation imaging system 1 includes a radiation generating device 300 that generates radiation, a control device 400 that controls the radiation generating device 300, and the radiation imaging device 100 described above.

[0058] The present disclosure can also configure an image processing device. In the image processing device, for example, for an image obtained in a certain imaging mode, an offset correction image that can be used in common for a group of imaging modes including the imaging mode exists, but offset correction can be performed even if there is no offset correction image for the imaging mode itself. Such an image processing device (image control device 500) can include an image data acquisition unit, an offset correction data acquisition unit, and an offset correction unit. The image data acquisition unit has, as an example, a function to acquire radiation image data obtained in each of a plurality of imaging modes, similar to the radiation image acquisition control unit 104. Also, the offset correction data acquisition unit has, as an example, a function to acquire offset correction data corresponding to each of a plurality of imaging modes, similar to the offset image acquisition control unit 105. The offset correction unit can use one offset correction data selected from the offset correction data corresponding to each of the imaging modes in which the common offset correction data can be used in the plurality of imaging modes. Then, the one offset correction data is used to offset correct the radiation image data obtained in each of the imaging modes in which the common offset correction data can be used.

[0059] (Other Examples) The present disclosure can also be realized by a process in which a program for implementing one or more functions of the above-described embodiments is provided to a system or device via a network or a storage medium, and one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) for implementing one or more functions. A computer may have one or more processors or circuits, and may include separate computers or a network of separate processors or circuits for reading and executing computer-executable instructions.

[0060] The processor or circuitry may include a central processing unit (CPU), a microprocessing unit (MPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), or a field programmable gateway (FPGA), and the processor or circuitry may include a digital signal processor (DSP), a data flow processor (DFP), or a neural processing unit (NPU).

[0061] The above disclosure includes the following configurations, methods, and programs. (Configuration 1) an image data acquisition unit that acquires radiation image data according to an imaging mode selected from a plurality of imaging modes for acquiring a plurality of types of radiation images; an offset correction data acquisition unit that acquires offset correction data corresponding to each of the plurality of shooting modes; an offset correction unit that corrects the radiation image data using the acquired offset correction data; a determination unit that determines an imaging mode in which common offset correction data can be used among the plurality of imaging modes, and selects offset correction data that the offset correction unit uses for correction of the determined imaging mode from among the offset correction data corresponding to each of the determined imaging modes; an updating unit that causes the offset correction data acquiring unit to acquire offset correction data corresponding to the selected offset correction data in order to update offset correction data used in the shooting mode in which it is determined that the common offset correction data can be used; A radiation imaging apparatus comprising: (Configuration 2) 2. The radiation imaging apparatus according to configuration 1, wherein the determination unit determines an imaging mode in which the common offset correction data can be used based on an average value of the offset correction data. (Configuration 3) 3. The radiation imaging apparatus according to configuration 1 or 2, wherein the determination unit determines an imaging mode in which the common offset correction data can be used, based on an amount of noise in the offset correction data. (Configuration 4) 4. The radiation imaging apparatus according to any one of configurations 1 to 3, wherein the determination unit determines an imaging mode in which the common offset correction data can be used, based on an in-plane distribution of the offset correction data. (Configuration 5) The radiation imaging device according to any one of configurations 1 to 4, wherein the determination unit selects offset correction data corresponding to the imaging mode having the maximum frame rate from among the offset correction data used for the imaging modes for which it has been determined that the common offset correction data can be used. (Configuration 6) The radiation imaging device according to any one of configurations 1 to 4, wherein the determination unit selects offset correction data corresponding to an imaging mode in which the noise amount of the offset correction data is the smallest from among the offset correction data used in the imaging modes in which it has been determined that the common offset correction data can be used. (Configuration 7) The radiation imaging device according to any one of configurations 1 to 4, wherein the determination unit selects offset correction data corresponding to the imaging mode having the smallest average value of the offset correction data from among the offset correction data used for the imaging modes for which it has been determined that the common offset correction data can be used. (Configuration 8) A radiation generating device that generates radiation; A control device for controlling the radiation generating device; A radiation imaging device according to any one of configurations 1 to 7; A radiation imaging system comprising: (Configuration 9) an image data acquisition unit that acquires radiation image data obtained in each of a plurality of imaging modes; an offset correction data acquisition unit that acquires offset correction data corresponding to each of the plurality of shooting modes; an offset correction unit that performs offset correction on radiation image data obtained in each of the imaging modes in which common offset correction data can be used, by using one offset correction data selected from among offset correction data corresponding to each of the imaging modes in which the common offset correction data can be used, in the plurality of imaging modes; A radiation image processing device comprising: (Method 1) acquiring radiation image data according to an imaging mode selected from a plurality of imaging modes for acquiring a plurality of types of radiation images; acquiring offset correction data corresponding to each of the plurality of imaging modes; correcting the radiation image data using the acquired offset correction data, determining an imaging mode in which common offset correction data can be used among the plurality of imaging modes, and selecting offset correction data to be used for correction of the determined imaging mode from among the offset correction data corresponding to the determined imaging mode; acquiring offset correction data corresponding to the selected offset correction data in order to update offset correction data used in the shooting mode in which it has been determined that the common offset correction data can be used; The method for controlling a radiation imaging apparatus further includes the steps of: (Method 2) acquiring radiation image data obtained in each of a plurality of imaging modes; acquiring offset correction data corresponding to each of the plurality of imaging modes; performing offset correction on radiation image data obtained in each of the imaging modes in which the common offset correction data can be used, using one offset correction data selected from among offset correction data corresponding to each of the imaging modes in which the common offset correction data can be used, in the plurality of imaging modes; An image processing method comprising: (Program 1) A program that, when executed by a processor, causes the processor to execute the control method for a radiation imaging apparatus according to the first method or the image processing method according to the second method.

[0062] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above embodiments. Inventions modified within the scope of the present disclosure and inventions equivalent to the present disclosure are also included in the present disclosure. In addition, the above-mentioned embodiments can be appropriately combined within the scope of the present disclosure. [Explanation of symbols]

[0063] 100: Radiation imaging device 101: Control unit 102: Drive control unit 103: Shooting preparation drive control unit 104: Radiation image acquisition control unit 105: Offset image acquisition control 106: Image processing unit 107: Offset correction section 108: Offset image update control unit 109: Storage section 112: Communication control unit 113: Internal clock 114: Radiation generating device control unit 120: Judgment Department 200: Radiation detection unit 300: Radiation Generator 301:Radiation source 400: Control device 500: Image control device 600:Hospital network

Claims

1. an image data acquisition unit that acquires radiation image data according to an imaging mode selected from a plurality of imaging modes for acquiring a plurality of types of radiation images; an offset correction data acquisition unit that acquires offset correction data corresponding to each of the plurality of shooting modes; an offset correction unit that corrects the radiation image data using the acquired offset correction data; a determination unit that determines an imaging mode in which common offset correction data can be used among the plurality of imaging modes, and selects offset correction data that the offset correction unit uses for correction of the determined imaging mode from among the offset correction data corresponding to each of the determined imaging modes; an updating unit that causes the offset correction data acquiring unit to acquire offset correction data corresponding to the selected offset correction data in order to update offset correction data used in the shooting mode in which it is determined that the common offset correction data can be used; A radiation imaging apparatus comprising:

2. The radiation imaging apparatus according to claim 1 , wherein the determining unit determines an imaging mode in which the common offset correction data can be used based on an average value of the offset correction data.

3. The radiation imaging apparatus according to claim 1 , wherein the determination unit determines an imaging mode in which the common offset correction data can be used based on an amount of noise in the offset correction data.

4. The radiation imaging apparatus according to claim 1 , wherein the determining unit determines an imaging mode in which the common offset correction data can be used based on an in-plane distribution of the offset correction data.

5. 2 . The radiation imaging apparatus according to claim 1 , wherein the determination unit selects offset correction data corresponding to an imaging mode having a maximum frame rate from among the offset correction data used in the imaging modes for which it has been determined that the common offset correction data can be used.

6. 2. The radiation imaging device according to claim 1, wherein the determination unit selects, from among the offset correction data used in the imaging modes for which it has been determined that the common offset correction data can be used, the offset correction data corresponding to the imaging mode in which the noise amount of the offset correction data is the smallest.

7. 2. The radiation imaging device according to claim 1, wherein the determination unit selects, from among the offset correction data used in the imaging modes for which it has been determined that the common offset correction data can be used, the offset correction data corresponding to the imaging mode having the smallest average value of the offset correction data.

8. A radiation generating device that generates radiation; A control device for controlling the radiation generating device; A radiation imaging apparatus according to any one of claims 1 to 7, A radiation imaging system comprising:

9. an image data acquisition unit that acquires radiation image data obtained in each of a plurality of imaging modes; an offset correction data acquisition unit that acquires offset correction data corresponding to each of the plurality of shooting modes; an offset correction unit that performs offset correction on radiation image data obtained in each of the imaging modes in which common offset correction data can be used, by using one offset correction data selected from among offset correction data corresponding to each of the imaging modes in which the common offset correction data can be used, in the plurality of imaging modes; A radiation image processing device comprising:

10. acquiring radiation image data according to an imaging mode selected from a plurality of imaging modes for acquiring a plurality of types of radiation images; acquiring offset correction data corresponding to each of the plurality of imaging modes; correcting the radiation image data using the acquired offset correction data; determining an imaging mode in which common offset correction data can be used among the plurality of imaging modes, and selecting offset correction data to be used for correction of the determined imaging mode from among the offset correction data corresponding to the determined imaging mode; acquiring offset correction data corresponding to the selected offset correction data in order to update offset correction data used in the shooting mode in which it has been determined that the common offset correction data can be used; A method for controlling a radiation imaging apparatus comprising:

11. acquiring radiation image data obtained in each of a plurality of imaging modes; acquiring offset correction data corresponding to each of the plurality of imaging modes; performing offset correction on radiation image data obtained in each of the imaging modes in which the common offset correction data can be used, using one offset correction data selected from among offset correction data corresponding to each of the imaging modes in which the common offset correction data can be used, in the plurality of imaging modes; An image processing method comprising:

12. A program that, when executed by a processor, causes the processor to execute the control method for a radiation imaging apparatus according to claim 10 or the image processing method according to claim 11.

Images