Radiation image imaging system and control method thereof and program

Abstract

To provide a technology capable of appropriately correcting an imaged radiation image even when radiation cannot be emitted to the entire surface of a radiation image imaging unit.SOLUTION: A radiation image imaging system includes: a radiation image imaging unit 1030 that images a radiation image on the basis of an incident radiation ray R; a first radiation irradiation range acquisition unit 1061 or a second radiation irradiation range acquisition unit 1062 that acquires a radiation irradiation range for imaging being an irradiation range of the radiation ray R when the radiation image is imaged in the radiation image imaging unit 1030; and a display unit 1170 that selectively displays at least one correction image from among a plurality of correction images having different irradiation conditions of the radiation ray R on the basis of the radiation irradiation range for imaging.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a radiation imaging system, a control method thereof, and a program.

Background Art

[0002] As a radiation imaging device (radiation imaging unit) used for medical image diagnosis and non-destructive inspection by radiation such as X-rays, a device in which pixels including a switching element such as a TFT and a conversion element such as a photoelectric conversion element using a semiconductor are arranged in a two-dimensional matrix has been put into practical use. In a radiation imaging device (radiation imaging unit) using a semiconductor, image processing such as gain correction processing and gradation processing is performed on the radiation image obtained by imaging, and image display is possible within several seconds after irradiation with radiation for imaging. In the product lineup of radiation imaging devices (radiation imaging units) using a semiconductor, sizes standardized by conventional films, CRs, etc. have been used. As the largest size among the standardized sizes of radiation imaging devices (radiation imaging units), for example, the full-size (about 17 inches × about 17 inches), the half-size (about 14 inches × about 17 inches), etc. can be mentioned. And when a radiation imaging device (radiation imaging unit) of a larger size is required, the conventional standardized size is devised and used. For example, as described in Patent Document 1, there is a method of overlapping a plurality of radiation imaging devices for imaging and performing image correction processing on the overlapping region. Thus, in recent years, there has been a need for an increase in the size of radiation imaging devices (radiation imaging units).

[0003] On the other hand, a radiation generating device (radiation generating unit) that generates radiation used for radiation imaging is attached with a radiation movable diaphragm (radiation diaphragm) so that radiation is irradiated only in the minimum necessary range and other ranges are shielded from radiation. There is a limit to the maximum irradiation field due to this radiation movable diaphragm (such as "JIS Z 4712:1998 Guide"), and it is restricted so that radiation is not irradiated in an area larger than the above-described standardized size depending on the arrangement during imaging.

Prior Art Documents

Patent Document

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Thus, even though the irradiation range of radiation by a radiation generating device is restricted by a radiation movable aperture, when the radiation imaging device is enlarged, there are cases where radiation cannot be irradiated over the entire surface of the radiation imaging device (radiation imaging unit) at a site such as a medical facility. In this case, there has been a problem that it is difficult to appropriately correct a radiation image taken by the radiation imaging device (radiation imaging unit) based on the incident radiation.

[0006] The present disclosure has been made in view of such problems, and an object thereof is to provide a technique capable of appropriately correcting a taken radiation image even when radiation cannot be irradiated over the entire surface of the radiation imaging unit.

Means for Solving the Problems

[0007] The radiation imaging system of the present disclosure includes a radiation imaging unit that takes a radiation image based on incident radiation, an acquisition unit that acquires a radiation irradiation range for imaging, which is the irradiation range of the radiation when the radiation image is taken in the radiation imaging unit, and a display unit that can selectively display at least one correction image from a plurality of correction images having different radiation irradiation conditions based on the radiation irradiation range for imaging.

Effects of the Invention

[0008] According to the present disclosure, even when radiation cannot be irradiated over the entire surface of the radiation imaging unit, it becomes possible to appropriately correct the taken radiation image.

Brief Description of the Drawings

[0009]

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Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments (embodiments) for carrying out the present disclosure will be described with reference to the drawings. In this specification, as the radiation according to the present disclosure, it is preferable to use X-rays, but it is not limited to this X-ray, and includes α-rays, β-rays, γ-rays, etc.

[0011] (First Embodiment) First, the first embodiment will be described.

[0012] FIG. 1 is a diagram showing an example of a schematic configuration of a radiation image imaging system 1000 according to the first embodiment. The radiation image imaging system 1000 of the present embodiment can be mainly used for medical purposes.

[0013] The radiation image capturing system 1000 in FIG. 1 includes a radiation generation unit 1010, a radiation aperture 1020, a radiation image capturing unit 1030, a visible light camera 1040, a first gain correction data storage unit 1051, and a second gain correction data storage unit 1052. Further, the radiation image capturing system 1000 in FIG. 1 includes a first radiation irradiation range acquisition unit 1061, a second radiation irradiation range acquisition unit 1062, a radiation generation control unit 1070, a data collection unit 1080, an image correction unit 1090, and a storage unit 1100. Further, the radiation image capturing system 1000 in FIG. 1 includes a radiation irradiation range storage unit 1110, a gain correction data selection unit 1120, a gain correction determination unit 1130, a CPU 1140, a main memory 1150, an operation panel 1160, a display unit 1170, and a bus 1180.

[0014] Based on the control of the radiation generation control unit 1070, the radiation generation unit 1010 irradiates the subject H and the radiation image capturing unit 1030 with radiation R through the radiation aperture 1020. The radiation aperture 1020 restricts the irradiation range (radiation irradiation range or radiation irradiation field) of the radiation R emitted from the radiation generation unit 1010. This radiation aperture 1020 is provided with a light source that irradiates visible light inside, and by lighting this light source, medical staff can grasp the approximate radiation irradiation range from the irradiation range (light irradiation range or light irradiation field) of the visible light that has passed through the radiation aperture 1020. The radiation image capturing unit 1030 captures a radiation image based on the incident radiation R (including the radiation R that has passed through the subject H). This radiation image capturing unit 1030 is, for example, a large-sized capturing unit such as a long one, and in this embodiment, it is assumed that the entire incident surface where the radiation R enters may not be irradiated with the radiation R. The visible light camera 1040 is, for example, attached to the radiation aperture 1020 and is set to be able to capture the entire area of the radiation image capturing unit 1030.

[0015] The first gain correction data storage unit 1051 and the second gain correction data storage unit 1052 store gain correction data including a gain correction image for correcting the difference in gain of the radiation image capturing unit 1030. For example, the gain correction image is obtained by irradiating the radiation image capturing unit 1030 with gain correction radiation R in a state where the subject H does not exist. In the example shown in FIG. 1, two gain correction data storage units 1051 and 1052 are provided, but in this embodiment, only one gain correction data storage unit may be provided. Also, in this embodiment, the gain correction data storage unit stores a plurality of gain correction data including a plurality of correction images with different irradiation conditions of the radiation R.

[0016] The first radiation irradiation range acquisition unit 1061 and the second radiation irradiation range acquisition unit 1062 acquire a radiation irradiation range for imaging, which is the irradiation range of the radiation R when a radiation image is captured by the radiation image capturing unit 1030. In the example shown in FIG. 1, two radiation irradiation range acquisition units 1061 and 1062 are provided, but in this embodiment, only one radiation irradiation range acquisition unit may be provided.

[0017] The radiation generation control unit 1070 controls the irradiation of the radiation R from the radiation generation unit 1010, for example, based on the control of the CPU 1140. The data collection unit 1080 collects gain correction data from the first gain correction data storage unit 1051, collects data on the radiation irradiation range for imaging from the first radiation irradiation range acquisition unit 1061, and collects corrected image data from the image correction unit 1090. The image correction unit 1090 corrects the radiation image using a correction image selected from at least one correction image that can be selectively displayed by the display unit 1170. As shown in FIG. 1, this image correction unit 1090 includes a first preprocessing unit 1091, a second preprocessing unit 1092, and an image processing unit 1093. The storage unit 1100 stores various types of information (including data) obtained as a result of the CPU 1140 performing various controls and various processes, for example.

[0018] The radiation irradiation range storage unit 1110 stores a correction radiation irradiation range, which is the irradiation range of the radiation R when each gain correction image among a plurality of gain correction images is acquired in the radiation image capturing unit 1030. The gain correction data selection unit 1120 selects the gain correction data to be used from among a plurality of gain correction data including a plurality of gain correction images. The gain correction determination unit 1130 performs various determinations regarding the gain correction data including the gain correction images.

[0019] The CPU 1140 comprehensively controls the overall radiation image capturing system 1000 and performs various processes. The main memory 1150 stores various information (including data) and programs necessary when the CPU 1140 performs various controls and various processes. Here, the various information (including data) and programs described as being stored in the main memory 1150 may be in a form stored in the storage unit 1100, for example. The operation panel 1160 is for a user such as a medical staff to perform operation inputs. Here, the information input by operation from the operation panel 1160 is input to and processed by the CPU 1140, for example. The display unit 1170 displays various information (including data) and various images based on the control of the CPU 1140, for example. The bus 1180 communicably connects the connected components.

[0020] When a user such as a medical professional receives a shooting order, they operate the operation panel 1160 to input and set the shooting conditions. Here, the shooting order includes inputs such as the shooting site, physique, age, and shooting purpose of the subject H. The set shooting conditions are set in the radiation generation unit 1010 and the radiation image shooting unit 1030 including radiation detection means having a plurality of pixels in a two-dimensional plane via the CPU 1140 and the bus 1180. Here, the shooting conditions to be set include the tube voltage and tube current of the radiation generation unit 1010, the irradiation time of the radiation R, the type of scatter radiation removal grid, the position of the subject H, and the like. A user such as a medical professional arranges the subject H and the radiation image shooting unit 1030. The radiation image shooting unit 1030 may be installed on an upright stand or may be installed inside the lying stand as shown in FIG. 1. In the case of a large radiation image shooting unit 1030, it is not essential to move the radiation image shooting unit 1030, and it is only necessary to move the radiation generation unit 1010 so that the shooting site of the subject H can be irradiated. The radiation R is restricted by the radiation aperture 1020 so that only the necessary range is irradiated with the radiation R. A visible light camera 1040 is attached to the radiation aperture 1020, and it is possible to grasp from the camera image displayed on the display unit 1170 the range (light irradiation range) in which the visible light irradiated from the light source of the radiation aperture 1020 is irradiated to the radiation image shooting unit 1030.

[0021] In addition, the display unit 1170 displays a plurality of correction images including the most recently acquired correction image, together with the acquisition result of the irradiation range (irradiation field) by image analysis using these correction images as inputs. A user such as a medical staff member compares the light irradiation range in the camera image captured by the visible light camera 1040 with the correction radiation irradiation range in the plurality of correction images via the display unit 1170 on which the camera image and the plurality of correction images are simultaneously displayed. Then, the user such as a medical staff member checks whether the light irradiation range in the camera image is included in the correction radiation irradiation range obtained in the correction image selected from the plurality of correction images. If it is not included, the radiation image capturing system 1000 performs navigation display on the display unit 1170 of information to that effect, together with information on the deviation amount with respect to the correction radiation irradiation range of the excess range, which is the portion of the light irradiation range not included in the correction radiation irradiation range. Then, the user such as a medical staff member moves the radiation generation unit 1010 or selects another correction image based on the information displayed on the display unit 1170, and finishes the preparation before irradiating the radiation R.

[0022] When using the large-sized radiation image capturing unit 1030, a gain correction image for correcting the difference in sensitivity of each pixel can be selected from the operation panel 1160. The position of the most recently acquired gain correction image is displayed on the display unit 1170 and selected on the operation panel 1160. Alternatively, selection is made on the operation panel 1160 based on the light irradiation field range in the camera image displayed on the display unit 1170.

[0023] The object H to be imaged is, for example, a human body. The radiographic imaging unit 1030 includes radiation detection means in which pixels each having a phosphor that converts incident radiation R into light and a photoelectric conversion element that converts the light generated by the phosphor into an electrical signal (image signal) are arranged in a two-dimensional plane. Here, the phosphor is formed within the effective pixel range (effective imaging region) of the radiographic imaging unit 1030. Also, in the radiographic imaging unit 1030, the electrical signal (image signal) obtained by the photoelectric conversion element is read out and driven in a drive circuit and a readout circuit, amplified after the readout drive, and converted from an analog signal into a digital signal to become image data. The image data obtained by the radiographic imaging unit 1030 is sent to the data collection unit 1080. The image data collected by the data collection unit 1080 is subjected to dark current correction processing, gain correction processing, defect correction processing, etc. in the first preprocessing unit 1091 and the second preprocessing unit 1092, and QA processing etc. is performed in the image processing unit 1093. Here, as the QA processing, tone processing, noise suppression processing, frequency processing, etc. are performed. The image processed by the image correction unit 1090 finally becomes a diagnostic image and is displayed on the display unit 1170.

[0024] Note that in the radiographic imaging system 1000, for example, the CPU 1140 etc. do not necessarily need to be implemented as a personal computer (PC), and may be implemented as an FPGA inside the radiographic imaging unit 1030.

[0025] Next, the processing procedure in the control method of the radiographic imaging system 1000 according to the first embodiment will be described.

[0026] FIG. 2A is a flowchart showing an example of the processing procedure at the time of factory shipment in the control method of the radiographic imaging system 1000 according to the first embodiment. In FIG. 2A, a flowchart showing an example of the processing procedure at the time of factory shipment in the first embodiment is shown as SS_A1. Specifically, the flowchart (SS_A1) at the time of factory shipment shown in FIG. 2A is a flowchart for performing the pre-shipment setting and setting inspection of the radiographic imaging unit 1030.

[0027] When the flowchart (SS_A1) at the time of factory shipment shown in FIG. 2A is started, first, in step S101, the radiation image capturing unit 1030 starts acquiring a correction image before shipment. Note that the processing of the flowchart shown in FIG. 2A is not an essential process when it is possible to irradiate the entire surface of the radiation image capturing unit 1030 with radiation R in a medical facility or the like.

[0028] Subsequently, in step S102, the inspector at the time of factory shipment arranges the radiation image capturing unit 1030 at a predetermined position in order to acquire a correction image before shipment (in this embodiment, a gain correction image). At the hospital or clinic where it is installed, it may not be possible to irradiate the entire surface of the radiation image capturing unit 1030 with radiation R at once. In contrast, in the factory inspection before shipment, since the distance between the radiation generating unit 1010 and the radiation image capturing unit 1030 can be increased, it is possible to irradiate the entire surface of the radiation image capturing unit 1030 with radiation R. In order to ship in a general state, it is desirable to use a radiation generating unit that can irradiate radiation R as uniformly as possible and is isotropic as the radiation generating unit 1010 used when acquiring a correction image before shipment (in this embodiment, a gain correction image). When using a widespread radiation generating unit 1010, by increasing the distance from the radiation image capturing unit 1030 and acquiring correction images at a plurality of rotation angles so as to cancel out the non-uniformity of the irradiation of radiation R caused by the anode and cathode directions, uniformity and isotropy are improved.

[0029] Subsequently, in step S103, the radiation image capturing system 1000 irradiates the entire surface of the radiation image capturing unit 1030 with radiation R from the radiation generating unit 1010, and first acquires a gain correction image at the imaging position of one radiation image capturing unit 1030. A plurality of gain correction images are acquired as will be described later.

[0030] Subsequently, in step S104, the radiation imaging system 1000 determines whether the gain correction image obtained in step S103 includes a plurality of gain correction images including a shooting angle of 180° at the shooting position. Here, the shooting angle refers to the angle in the vertical, horizontal, left, and right directions of the radiation imaging unit 1030 as viewed from the anode-cathode direction of the radiation generation unit 1010. At the time of factory shipment, the inspector grasps whether the images are obtained at a relative angle of 0° and 180° on the same plane with the center of the radiation imaging unit 1030 as the center. This is to reduce the heel effect in the anode-cathode direction of the radiation generation unit 1010. When the shape of the incident surface where the radiation R enters in the radiation imaging unit 1030 is not a regular polygon shape, it is desirable to obtain the images at a relative angle of 0° and 180° on the same plane with the anode-cathode direction on the short side in the radiation generation unit 1010. It is desirable to obtain a plurality of images at each angle because quantum noise exists in the radiation R. If there is quantum noise in the correction image, quantum noise may appear like a smeared glass on the corrected diagnostic image.

[0031] As a result of the determination in step S104, if the gain correction image obtained in step S103 does not include a plurality of gain correction images including a shooting angle of 180° (S104 / NO), the process proceeds to step S105. When the process proceeds to step S105, the inspector at the time of factory shipment rotates the radiation imaging unit 1030. Then, the process returns to step S102, and the processes after step S102 are performed again.

[0032] On one hand, if as a result of the determination in step S104, the gain correction image obtained in step S103 includes a plurality of gain correction images including a shooting angle of 180° (S104 / YES), the process proceeds to step S106. When the process proceeds to step S106, the radiation image shooting system 1000 synthesizes a plurality of gain correction images based on the shooting angle to generate a synthesized gain correction image. Here, it is desirable to average the gain correction images at the first stage for each rotated angle and then average and synthesize the gain correction images for each rotated angle. If all the gain correction images are simply averaged and synthesized, there may be a radiation generation distribution irradiated from the radiation generation unit 1010 due to the difference in the number of images for each rotation angle of the radiation image shooting unit 1030 when viewed from the anode-cathode direction of the radiation generation unit 1010.

[0033] Subsequently, in step S107, the inspector at the time of factory shipment determines the gain correction image (synthesized gain correction image). When obtaining the gain correction image at the installation destination hospital or clinic, for example, even if there is dust attached to the surface of the radiation generation unit 1010, it can be removed immediately in the corresponding environment, so there may be no problem. However, regarding the gain correction image at the time of factory shipment, if scratches, dust, etc. are reflected in the image, they will be reflected in each image when used at the installation destination hospital or clinic. Therefore, it is necessary to conduct an inspection before factory shipment. As the inspection method, it is desirable to use qualitative evaluation such as visual evaluation and quantitative evaluation complementarily.

[0034] If the result of the determination (inspection) in step S107 is OK, in step S108, the radiation image shooting system 1000 stores the synthesized gain correction image generated in step S106, for example, in the second gain correction data storage unit 1052.

[0035] Subsequently, in step S109, the inspector at the time of factory shipment completes the pre-shipment inspection.

[0036] In the case of a conventional radiation image capturing unit with a standardized film size, it was possible to omit the processing according to the flowchart at the time of factory shipment. However, in the case of a capturing unit having a rectangular effective pixel range with a long side length of 18 inches or more or a diagonal length of 25 inches or more assumed by the radiation image capturing unit 1030 of the present embodiment, problems may occur if the flow before factory shipment in FIG. 2A is not performed. In a standardized radiation image capturing unit with a size of 17 inches or less, it is possible to irradiate the entire surface with radiation R at the installation site such as a hospital or a clinic. For this reason, in a standardized radiation image capturing unit with a size of 17 inches or less, it was possible to reduce the cost of the pre-shipment process by acquiring a correction image according to the post-installation environment after installation. On the other hand, for the radiation image capturing unit 1030 with a long side length of 18 inches or more, since there are restrictions such as the radiation aperture 1020 in "JIS Z 4712:1998 Guide", the flow before factory shipment in FIG. 2A is necessary processing.

[0037] FIG. 2B is a flowchart showing an example of a processing procedure at the time of installation / periodic inspection in the control method of the radiation image capturing system 1000 according to the first embodiment. In FIG. 2B, a flowchart showing an example of the processing procedure at the time of installation / periodic inspection in the first embodiment is shown as SS_B1. Further, the processing of the flowchart (SS_B1) at the time of installation / periodic inspection shown in FIG. 2B can be performed after the processing of the flowchart (SS_A1) at the time of factory shipment shown in FIG. 2A is completed.

[0038] When the flowchart (SS_B1) at the time of installation / periodic inspection shown in FIG. 2B is started, first, in step S201, the radiation image capturing system 1000 irradiates the radiation image capturing unit 1030 with radiation R from the radiation generation unit 1010 in the installation environment. Then, the radiation image capturing system 1000 acquires a gain correction image based on the radiation R irradiated to the radiation image capturing unit 1030. The radiation image capturing unit 1030 having an effective pixel range with a long side length of 18 inches or more is difficult to handle from the viewpoints of weight and size. For this reason, the number of times of not removing it from the standing gantry or the lying gantry is overwhelmingly larger than that of the conventional standardized radiation image capturing unit with a size of 17 inches or less. When the radiation image capturing unit 1030 is installed, for example, it is arranged on the lying gantry. For this reason, in the installation environment, by acquiring the gain correction image, it is possible to correct peculiar scattered rays and unevenness in the installation environment. However, for example, when the radiation image capturing unit 1030 having a rectangular effective pixel range with a long side length of 18 inches or more or a diagonal length of 25 inches or more is installed on the lying gantry, the following problems may occur. That is, due to the limitation in the radiation aperture 1020, it may not be possible to acquire an appropriate gain correction image over the entire effective pixel range.

[0039] Subsequently, in step S202, the radiation image capturing system 1000 acquires a correction radiation irradiation range, which is the irradiation range of the radiation R when the gain correction image acquired in step S201 is acquired in the radiation image capturing unit 1030. At this time, it is preferable to acquire the correction radiation irradiation range by using an irradiation field recognition function in image processing for the gain correction image, or it may be acquired by a method in which the user makes four-point instructions for the displayed gain correction image.

[0040] Subsequently, in step S203, the radiation image capturing system 1000 stores, for example, the gain correction image in the second gain correction data storage unit 1052, and stores the radiation irradiation range for correction in association with the radiation irradiation range storage unit 1110. Since the memory of the second gain correction data storage unit 1052 also has a capacity, the gain correction image may also be stored in the first gain correction data storage unit 1051 so that it can be called by an operation input on the operation panel 1160 or the like.

[0041] Subsequently, in step S204, the radiation image capturing system 1000 determines, for example, based on an operation input on the operation panel 1160, whether to acquire a gain correction image in another effective pixel range of the radiation image capturing unit 1030. As a result of this determination, if a gain correction image is to be acquired in another effective pixel range of the radiation image capturing unit 1030 (S204 / YES), the process returns to step S201, and the processes after step S201 are performed in another installation environment.

[0042] On the other hand, as a result of the determination in step S204, if a gain correction image is not acquired in another effective pixel range of the radiation image capturing unit 1030 (S204 / NO), the process proceeds to step S205. When the process proceeds to step S205, the user completes the installation or the regular inspection.

[0043] FIG. 2C is a flowchart showing an example of a processing procedure when in use at the installation location in the control method of the radiation image capturing system 1000 according to the first embodiment. In FIG. 2C, a flowchart showing an example of the processing procedure when in use at the installation location in the first embodiment is shown as SS_C1. Further, the processing of the flowchart (SS_C1) when in use at the installation location shown in FIG. 2C can be performed after the processing of the flowchart (SS_B1) at the time of installation / regular inspection shown in FIG. 2B is completed.

[0044] When performing a radiograph at a hospital, clinic, or the like, for example, when there are a plurality of gain correction images in step S204 of FIG. 2B, it is necessary to perform the imaging within an image area where gain correction is possible. Therefore, first, in step S301, the radiation image imaging system 1000 displays a gain correction possible area on the display unit 1170. An example of the displayed screen will be described later with reference to FIG. 5 and the like, but it is desirable that it can correspond to the large radiation image imaging unit 1030 in the actual real space.

[0045] Subsequently, in step S302, the gain correction data selection unit 1120 selects a gain correction image to be used from among a plurality of gain correction images, for example, based on an operation input on the operation panel 1160. Here, for example, the gain correction image is selected based on an area where gain correction is possible, whether the acquisition is the latest, whether the gain correction image was acquired in the same installation environment, and the like. Usually, since the radiation generation unit 1010 and the radiation image imaging unit 1030 do not often move significantly, steps S301 and S302 may be omitted. That is, it may be set to use the gain correction image used in the pre-imaging.

[0046] Subsequently, in step S303, the radiation image imaging system 1000 performs a radiograph of the subject H. A user such as a medical staff places the subject H at a position where it can be radiographed, and moves the radiation generation unit 1010 to narrow the range of radiation R irradiated at the radiation aperture 1020 so that the region of interest of the subject H can be imaged. At this time, it is desirable to move within the range of the area where gain correction is possible in steps S301 and S302 so that the region of interest of the subject H can be radiographed. The radiation R generated by the radiation generation unit 1010 according to the radiation generation conditions set on the operation panel 1160 is narrowed in the irradiation field by the radiation aperture 1020, and a radiograph of the region of interest of the subject H is performed. Then, the radiation image imaging unit 1030 takes a radiation image based on the incident radiation R (including the radiation R that has passed through the subject H).

[0047] Subsequently, in step S304, the image correction unit 1090 performs image processing such as gain-correcting the radiation image captured in step S304 using the gain-correction image selected in step S302. Here, the image processing includes pre-processing (dark current correction processing, gain correction processing, defective pixel correction processing), post-processing (tone processing, frequency processing), and the like.

[0048] Subsequently, in step S305, the display unit 1170 performs image display for confirmation of the radiation image (captured image) that has been image-processed in step S304.

[0049] Subsequently, in step S306, for example, the CPU 1140 or the gain correction determination unit 1130 determines whether it is okay or not with the currently selected gain-correction image based on, for example, an operation input from the operation panel 1160.

[0050] If, as a result of the determination in step S306, it is not okay (NG) with the currently selected gain-correction image (S306 / NO), the process proceeds to step S307. When the process proceeds to step S307, the radiation image capturing system 1000 again displays the gain-correction available area on the display unit 1170.

[0051] Subsequently, in step S308, the gain-correction data selection unit 1120 selects again, based on, for example, an operation input from the operation panel 1160, a gain-correction image to be used (a gain-correction image different from the previous one) from among a plurality of gain-correction images. Then, the process returns to step S304, and processing using the gain-correction image selected in step S308 is performed. Here, if there is no gain-correction image having an appropriate radiation irradiation range for correction, since the gain-correction image at the time of factory shipment is stored in the second gain-correction data storage unit 1052 etc. in step S108 of FIG. 2A, this gain-correction image can also be selected. Thus, it is desirable to have at least one gain-correction image that covers the entire surface of the radiation image capturing unit 1030 as the radiation irradiation range.

[0052] Also, if as a result of the determination in step S306, the currently selected gain correction image is OK (S306 / YES), the process proceeds to step S309. When the process proceeds to step S309, the radiation image capturing system 1000 stores the captured radiation image.

[0053] FIG. 3 shows the first embodiment and is a diagram for explaining a radiation irradiation range (radiation irradiation field) which is the irradiation range of radiation R in the radiation image capturing unit 1030. In FIG. 3, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

[0054] FIG. 3(a) shows the radiation generation unit 1010, the radiation collimator 1020, and the radiation image capturing unit 1030. Further, FIG. 3(a) shows an example in which the radiation image capturing unit 1030 is attached to a supine gantry. FIG. 3(a) also shows a radiation irradiation range (radiation irradiation field) 3010 which is the irradiation range of the radiation R irradiated to the radiation image capturing unit 1030 via the radiation generation unit 1010 and the radiation collimator 1020. Furthermore, FIG. 3(a) also shows a foot switch 3020 capable of raising and lowering the height of the supine gantry to which the radiation image capturing unit 1030 is attached.

[0055] When the length of the long side of the effective pixel range of the radiation imaging unit 1030 becomes 18 inches or more, its weight increases according to the size of the effective pixel range, making it difficult to handle and not easily movable. Users such as medical staff move the radiation generation unit 1010 suspended from the ceiling to a position where the subject H can be irradiated with radiation R. The radiation R generated from the radiation generation unit 1010 is collimated by the radiation collimator 1020 and irradiated onto the large-sized radiation imaging unit 1030. According to, for example, the "JIS Z 4712:1998 Guide" for diagnostic X-ray movable collimators, the maximum X irradiation field of the radiation collimator 1020 is "not exceeding 35 cm × 35 cm at SID 65 cm." The area of the radiation irradiation range (radiation irradiation field) 3010 is proportional to the square of the distance from the radiation generation unit 1010. Fig. 3(b) is a diagram showing how the areas of the radiation irradiation ranges (radiation irradiation fields) 3011, 3012, and 3013 increase in proportion to the square of the distances (r, 2r, 3r). Assuming that the area of the radiation irradiation range (radiation irradiation field) 3011 at the imaging distance r = 65 cm is 35 cm × 35 cm, the area of the radiation irradiation range (radiation irradiation field) 3012 at the imaging distance 2r = 130 cm is 70 cm × 70 cm. Similarly, the area of the radiation irradiation range (radiation irradiation field) 3013 at the imaging distance 3r = 195 cm is 105 cm × 105 cm.

[0056] The size standards for conventional X-ray films are, for example, · Large size: 43.2 cm × 43.2 cm (17 inches × 17 inches) · Half cut: 35.6 cm × 43.2 cm (14 inches × 17 inches) · Large angle: 35.6 cm × 35.6 cm (14 inches × 14 inches) · Quarter cut: 25.4 cm × 30.5 cm (10 inches × 12 inches) and are as follows.

[0057] Therefore, if the size of the radiation imaging unit 1030 is 43.2 cm (17 inches) or less, irradiating the entire surface of the radiation imaging unit 1030 with radiation R would not be impossible as long as the imaging distance is set to 80 cm or more. Even for a radiation imaging unit using a semiconductor, in order to be insertable into a conventional standing or lying gantry and be usable without changing the usability for users such as radiologic technologists, it was often designed to be approximately the same size as an X-ray film. When it is necessary to take images of a larger size, imaging was performed by overlapping multiple radiation imaging units or by moving the radiation imaging unit and the radiation generation unit step by step. However, if the size of the radiation imaging unit is 43.2 cm × 86.4 cm (17 inches × 34 inches) for two units, an imaging distance of 160 cm or more is required. Furthermore, if the size is 43.2 cm × 129.6 cm (17 inches × 51 inches) for three units, an imaging distance of 240 cm or more is required.

[0058] In recent years, in semiconductor manufacturing equipment, it has become possible to manufacture large flat panels, and it has also become possible to manufacture radiation imaging units sized for two or three half-sized panels. Further, in the future, if these large flat panels can be tiled side by side without gaps at the pixel level, it would be possible to use, for example, an entire wall or floor as a radiation imaging unit.

[0059] The radiation aperture (X-ray aperture) is restricted so that radiation (X-ray) is not irradiated, as described in "JIS Z 4712:1998 Guide" etc. Although an example of JIS is given here, the aperture range may vary slightly from country to country. When acquiring a radiation image in a single radiation imaging using multiple radiation imaging units, when installed on a standing gantry, gain correction was possible if the imaging distance was set to 250 cm etc. However, when installed on a lying gantry or when using an entire wall as a radiation imaging unit, countermeasures are necessary.

[0060] On the one hand, the critical size of the radiation aperture (X-ray aperture) is very narrow. When the imaging distance is 100 cm, the length of the long side is approximately 53.8 cm (the length of the long side is 21.2 inches, and the length of the diagonal is 29.9 inches). When the imaging distance is 110 cm, the length of the long side is 59.2 cm (the length of the long side is 23.3 inches, and the length of the diagonal is 32.9 inches). If a radiation image capturing unit smaller than these sizes is used, it is difficult to capture an image with a single radiation exposure, resulting in the occurrence of seams.

[0061] Calibration can be classified into calibration using radiation R and calibration without using radiation R. Calibration using radiation R includes gain correction, afterimage correction, etc. Gain correction irradiates radiation R in advance to obtain correction data (e.g., gain correction image) in order to correct the gain differences for each pixel of the radiation image capturing unit 1030 and the sensitivity distribution of the phosphor. Afterimage correction irradiates radiation R over the entire surface in advance to obtain correction data based on the time until the next radiation R is irradiated and the amount remaining in the image in order to correct the afterimages that differ for each model of the radiation image capturing unit 1030. Calibration without using radiation R includes dark current correction for correcting the variation in dark current for each pixel of the radiation image capturing unit 1030.

[0062] Calibration using radiation R has an issue that seams in irradiation may occur when the size of the radiation image capturing unit 1030 exceeds a predetermined size and it is impossible to irradiate radiation R over the entire surface of the radiation image capturing unit 1030 in the hospital or clinic where it is installed. In particular, gain correction must be performed for all pixels of the radiation image capturing unit 1030. The radiation image capturing unit 1030 using a semiconductor is manufactured so that the characteristics of each pixel are well aligned, but still the characteristics slightly differ for each pixel. Gain correction corrects the non-uniformity of all pixels (about 10 million pixels) of this radiation image capturing unit 1030. The basic correction process is as follows. Corr(x,y)=[Orig(x,y)-Offset(x,y)] / White(x,y) White(x,y) = Σ(n = 1 to N) [White(x,y)n - Offset(x,y)n] / N Here, Corr(x,y) is the corrected image. Also, Orig(x,y) is the image before correction. Offset(x,y) is the image for offset correction. White(x,y) is the image for gain correction.

[0063] Gain correction is to use a flat image without the subject H and output this image to be uniform. Since the gain correction image is obtained by irradiation with radiation R, it cannot be said to be completely uniform. The non-uniformity can be roughly separated into two elements. The first element is shading due to the anode heel effect of the radiation generation unit, etc. Shading is a low spatial frequency pattern with a gently changing intensity. The second element is radiation quantum noise. Quantum noise due to radiation quanta is inevitably superimposed on the radiation image. Since its S / N is proportional to the square root of the dose, it can be improved by increasing the dose. In gain correction, these non-uniform radiation images are assumed to be uniform and gain correction is performed. Also, since the non-uniformity of the radiation image acquisition unit also has two aspects of shading and variation for each pixel, it is impossible to separate whether the non-uniformity observed when the gain correction image is taken is derived from the radiation image or from the radiation image acquisition unit. Also, in the case of the heel effect, if the tube of the radiation generation unit is turned upside down and used, the heel effect will be doubled. Although there is no problem with the standing stand first, attention is required for the supine table.

[0064] Some facilities perform daily calibration, including the meaning of daily inspections, depending on the user. However, in the radiation image capturing unit 1030 with a large effective pixel range (effective imaging area), it may not be possible to irradiate the entire effective pixel range with radiation at once. Therefore, gain correction is appropriately performed using a method applicable to the present disclosure. In addition, since ambient environmental changes and replacement of the radiation generation unit 1010 may also occur, it is necessary to incorporate means in the radiation image capturing system 1000 to obtain correction images in hospitals and clinics. Also, in the case of the standing type, it was possible to separate the radiation generation unit 1010 by 2 m or more. However, in the case of the lying type, there are limitations in the ceiling height, and considering that the height of the lying bed needs to be 80 cm to 100 cm, it is often impossible to separate the distance by 1.5 m (150 cm) or more. When the imaging distance is 150 cm, the effective pixel range has a critical size where the length of the long side is approximately 80.8 cm (the length of the long side is 31.8 inches, and the length of the diagonal is 44.8 inches). In the radiation image capturing unit 1030 with an effective pixel range larger than the above, in the arrangement of the lying device usually used, it becomes difficult to perform regular calibration and the like.

[0065] Also, in the usage environment of the radiation image capturing unit 1030, as the effective pixel range of the radiation image capturing unit 1030 becomes larger, a radiation irradiation area with a higher frequency and a radiation irradiation area with a lower frequency are generated, and a difference in the cumulative radiation irradiation amount appears. It is based on a phosphor, which is a material that converts radiation (X-ray) R into light. For example, when CsI is used for the phosphor, as a result of long-term use, due to the difference in the cumulative radiation irradiation amount, there may be differences in granularity and gain in the radiation image. Of course, if it is returned to the factory or the like, full-scale gain correction can be prepared. However, in small hospitals and clinics, etc., it may not be possible to perform imaging involving radiation irradiation on the entire surface of the radiation image capturing unit 1030. In such a case, in each hospital and clinic, there may be a need to apply gain correction only to a partial area of the radiation image capturing unit 1030 and irradiate with radiation R.

[0066] FIG. 4 shows a first embodiment and is a diagram showing an installation example of the radiation image capturing unit 1030. In this FIG. 3, the same components as those shown in FIGS. 1 and 3 are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0067] In FIG. 4(a), the radiation generation unit 1010 is suspended from the ceiling by a support column 4010, enabling height and position changes within the radiation room. In FIG. 4(a), the radiation generation unit 1010 is provided with a radiation aperture 1020, which can shield radiation outside a predetermined range from the radiation emitted omnidirectionally. The radiation image capturing unit 1030-2 is a radiation image capturing unit for standing position imaging. The radiation image capturing unit 1030-2 is supported by a standing position gantry 4020 and is equipped with mechanisms such as an up-and-down movement mechanism and a mechanism for manually grasping to reduce the amount of movement of the subject during imaging. In this embodiment, by placing the radiation image capturing unit 1030-2 inside the standing position gantry 4020, the operation of moving the radiation image capturing unit 1030-2 up and down is eliminated, and it becomes possible to irradiate the subject H with radiation R for imaging.

[0068] In the same radiation room, a lying position ceiling plate 4030 capable of lying position imaging is arranged. Similar to the standing position gantry 4020, it is possible to place a radiation image capturing unit 1030-1 of 18 inches or more to which the present disclosure is applicable inside the lying position ceiling plate 4030. In addition to FIG. 4(a), FIG. 4(b) also illustrates this state. By simply moving the radiation generation unit 1010, it is possible to set the radiation irradiation range (radiation irradiation field) 3010 without horizontally moving the radiation image capturing unit 1030-1 or the lying position ceiling plate 4030, and it becomes possible to image the subject H. The fact that the lying position ceiling plate 4030 and the subject H do not move during the inspection is beneficial for performing the inspection safely. For example, when performing an inspection involving puncture, if the lying position ceiling plate 4030 and the subject H move, it may be necessary to consider safety, or it may be necessary to consider that the fiber scope cord of the endoscope is not pinched during movement.

[0069] The height 4041 of the lying position top plate 4030 shown in FIG. 4(a) is set to, for example, 70 cm which is the standard height of a bed. When placing the subject H on the lying position top plate 4030, it is also possible to move the height up and down and lower it to a height of 30 cm to 40 cm. The foot switch 3020 shown in FIG. 4(b) for adjusting the height 4041 of the lying position top plate 4030 can be controlled without using both hands, and when raising or lowering the height 4041, it stops once at the preset standard height of 70 cm.

[0070] Users such as medical staff measure the distance using the column graduations on the column 4010, or the tape-type distance measuring means or laser-type distance measuring means attached to the radiation aperture 1020 or the radiation generating unit 1010, and usually set the shooting distance to 90 cm to 130 cm. The ceiling height 4042 is determined by construction scales according to the construction method, such as 240 cm to 280 cm. When the height 4041 of the lying position top plate 4030 is 70 cm and the shooting distance is 130 cm, the height of the radiation generating unit 1010 becomes 200 cm. Due to the size of the radiation generating unit 1010 hitting the ceiling suspension, there may be limitations when raising it to increase the distance. Also, for female medical staff etc., it becomes difficult to adjust to a height of 200 cm. For this reason, there is a limitation in setting the shooting distance to around 90 cm to 120 cm, and many medical facilities set the shooting distance to around 100 cm in lying position photography.

[0071] The maximum X-ray irradiation field (radiation irradiation range) that satisfies the "JIS Z 4712:1998 Guide" ) is as follows. When the shooting distance is 90 cm, with a diagonal of approximately 48.4 cm (about 19 inches) and 27 inches or more, and when the shooting distance is 100 cm, with a diagonal of approximately 53.8 cm (about 21 inches) and 30 inches or more, X-ray irradiation (radiation irradiation) is impossible. Therefore, for a radiation image capturing unit 1030 exceeding this size, when used in the lying position, it is impossible to capture radiation R over the entire effective pixel range. When using a large-sized radiation image capturing unit 1030 with a short side length exceeding 19 inches (diagonal length of 27 inches) in the lying position, as described above, there are very many advantages such as safety, shortening of the imaging preparation time, reduction of the horizontal movement mechanism, etc.

[0072] On the other hand, the larger the radiation image capturing unit 1030 becomes, the more likely it is to be divided into an area frequently irradiated with radiation R and an area not so irradiated. The semiconductors and phosphors inside the radiation image capturing unit 1030 may have differences in sensitivity and noise after being used for many years depending on the amount of accumulated radiation. In the initial stage after installation, the gain correction image obtained in the flowchart (SS_A1) at the time of factory shipment shown in FIG. 2A can be used. However, changes in characteristics due to the accumulated radiation dose over the years may occur. For this reason, it is desirable to use a gain correction image obtained as recently as possible.

[0073] Also, if limited to the standing gantry 4020, it was also possible to limit the imaging to only a determined geometric arrangement by overlapping a plurality of conventional radiation image capturing units. However, in many cases, limiting the imaging to only a determined geometric arrangement is substantially inconvenient. Also, although measures such as returning to the factory once to obtain a gain correction image can be cited, it may be substantially difficult in remote areas, etc.

[0074] In the radiation imaging unit 1030 to which the present disclosure is applicable, in the region irradiated with the radiation R, gain correction images are acquired in a plurality of radiation irradiation element ranges, and at each acquisition time, an appropriate gain correction image can be selected using the radiation irradiation range information. Further, for example, the present disclosure can also be applied to an FPD on a wall surface (radiation imaging unit 1030) or an FPD on a bed surface (radiation imaging unit 1030).

[0075] FIG. 5 is a diagram showing an example of a screen that can be displayed on the display unit 1170 in the radiation imaging system 1000 according to the first embodiment.

[0076] The screen 501 shown in FIG. 5(a) is a screen for acquiring the radiation irradiation range and has the functions of the display unit 1170 and the operation panel 1160. On the screen 501, a radiation image 510 that is a captured image, a first correction image (in this embodiment, a first gain correction image) 520, and a second correction image (in this embodiment, a second gain correction image) 530 are displayed. The outer frames of the radiation image 510, the first correction image 520, and the second correction image 530 indicate, for example, the entire surface of the incident surface of the radiation R of the radiation imaging unit 1030.

[0077] In the radiation image 510 that is a captured image, the radiation image region of the subject H is the radiation irradiation range 511 for imaging.

[0078] In the first correction image 520, the shaded area is the radiation irradiation range 521 for correction. Further, near the first correction image 520, information regarding the first correction image 520 (information on the acquisition time in the example shown in FIG. 5) 522 and a selection 1 button 523 that is operated when selecting the first correction image 520 are shown.

[0079] In the second correction image 530, the shaded area is the radiation irradiation range 531 for correction. Also, near the second correction image 530, information about the second correction image 530 (in the example shown in FIG. 5, information about the acquisition time) 532 and a selection 2 button 533 that is operated when selecting the second correction image 530 are shown.

[0080] Here, in the example shown in FIG. 5, the information 522 about the first correction image 520 and the information 532 about the second correction image 530 display the information about their respective acquisition times, but the present embodiment is not limited to this. For example, information indicating in which radiation room the correction image was acquired, information indicating whether it was acquired in the standing position or the lying position, etc. may also be additionally displayed. Also, the second correction image 530 may be a candidate correction image for the next point (for example, the next in terms of usage frequency) in the first correction image 520. Also, as the first correction image 520 or the second correction image 530, the gain correction image saved at the time of factory shipment in FIG. 2A may be displayed. Also, since there is a limit to the number of images that can be displayed on the screen 501, it is desirable to preset the display order of the candidate gain correction images.

[0081] In the example of the screen 501 shown in FIG. 5(a), the first correction image 520, which is the most recently acquired correction image, is displayed together with its radiation irradiation range 521 for correction. When another correction image is acquired, the second correction image 530, which is the second closest correction image from the current location, is displayed together with its radiation irradiation range 531 for correction. In the example shown in FIG. 5(a), the second correction image 530 is a correction image acquired, for example, 36 months before factory shipment, from the information 532 about the acquisition time.

[0082] In the example shown in FIG. 5(a), the radiation irradiation range 511 for imaging in the radiation image 510, which is the captured image, does not include a partial range (the range below the radiation irradiation range 511 for imaging) in the radiation irradiation range 521 for correction in the first correction image 520. In this case, when a user such as a medical staff operates the selection 1 button 523 and selects the first correction image 520 as the correction image for correcting the radiation image 510, an appropriate correction (gain correction in this embodiment) cannot be performed on the radiation image 510. On the other hand, in the example shown in FIG. 5(a), the radiation irradiation range 511 for imaging in the radiation image 510 includes all ranges in the radiation irradiation range 531 for correction in the second correction image 530. In this case, when a user such as a medical staff operates the selection 2 button 533 and selects the second correction image 530 as the correction image for correcting the radiation image 510, an appropriate correction (gain correction in this embodiment) can be performed on the radiation image 510. In this embodiment, the display unit 1170 is configured to display selectably at least one correction image 530 that can be appropriately corrected from among a plurality of correction images 520 and 530 having different radiation irradiation conditions of the radiation R, based on the radiation irradiation range 511 for imaging in the radiation image 510. In the example shown in FIG. 5(a), one correction image 530 is displayed as the correction image having a radiation irradiation range for correction that includes all of the radiation irradiation range 511 for imaging in the radiation image 510, but in this embodiment, two or more correction images may be displayed. Also, in this embodiment, the display unit 1170 is configured to display the radiation irradiation range 511 for imaging and the plurality of radiation irradiation ranges 521 and 531 for correction in the plurality of correction images 520 and 530 in a comparable manner. Thereby, the user can select at least one correction image 530 that can be appropriately corrected from among the plurality of correction images 520 and 530 by visually recognizing the compared and displayed radiation irradiation range 511 for imaging and the plurality of radiation irradiation ranges 521 and 531 for correction.

[0083] In this embodiment, the radiation irradiation range 511 for imaging may be obtained by image analysis of the radiation image 510. Similarly, in this embodiment, the radiation irradiation range 521 for correction may be obtained by image analysis of the first correction image 520, and the radiation irradiation range 531 for correction may also be obtained by image analysis of the second correction image 530. The threshold value in this image analysis can be set and changed by the user via the operation panel 1160. The method for obtaining the radiation irradiation range may be a method other than the above-described image analysis, for example, a method in which the user makes an operation input of four points indicating the boundary of the radiation irradiation field range on the screen 501. Further, the above-described radiation irradiation range may be obtained using one or more pieces of information among the information on the focal position of the radiation generation unit, the relative position information between the radiation generation unit and the radiation image capturing unit, the relative angle information, the imaging distance information therebetween, and the aperture opening information of the radiation aperture.

[0084] The user determines whether to operatively select the selection 1 button 523 for the first correction image 520 or the selection 2 button 533 for the second correction image 530 based on the radiation irradiation range 511 for imaging in the radiation image 510 on the screen 501 in FIG. 5(a). When the user makes a determination, the display unit 1170 may display at least one piece of information of the anode (+) and the cathode (-) of the radiation generation unit 1010 in the correction image. In the screen 501 shown in FIG. 5(a), the information of the anode (+) and the cathode (-) of the radiation generation unit 1010 is displayed in the first correction image 520.

[0085] Then, the image correction unit 1090 corrects (gain correction in this embodiment) the radiation image 510 using the correction image (for example, the second correction image 530) selected from at least one correction image that is selectively displayed by the display unit 1170.

[0086] The screen 502 shown in FIG. 5(b) is a screen displayed on the display unit 1170 when calibrating the light irradiation range (light irradiation field) which is the irradiation range of light from the light source of the radiation diaphragm 1020. The calibration of the above-described light irradiation range (light irradiation field) is performed periodically in advance. The radiation diaphragm 1020 differs for each medical facility, and may be adjusted by the service person in charge of the radiation generation unit 1010 at the medical site. In the present embodiment, it is desirable to calibrate the above-described light irradiation range (light irradiation field) periodically in advance. On the screen 502 shown in FIG. 5(b), an exterior image 550 of the radiation image capturing unit 1030 and a light irradiation field calibration image 560 are displayed. On the screen 502 shown in FIG. 5(b), first, a display saying "Please take a picture with the light irradiation field aligned with this range." appears. The target light irradiation range 551 is shown together with the exterior image 550 of the radiation image capturing unit 1030. Then, the result of taking a picture with the light irradiation field aligned with the target light irradiation range 551 is displayed on the light irradiation field calibration image 560. In the light irradiation field calibration image 560, the irradiation range of the actual radiation R is illustrated as a radiation irradiation range 561. Then, the difference between the target light irradiation range 551 and the actual radiation irradiation range 561 is displayed as a left difference 562 and a right difference 563 on the X-axis, and an upper difference 564 and a lower difference 565 on the Y-axis. And the result of calibrating the difference between the radiation irradiation range and the light irradiation range is displayed in the light irradiation range calibration result display area 540 shown in FIGS. 5(a) and 5(b), together with the calibration date and year. Note that in FIG. 5, the illustration is based on a rectangular (square) radiation irradiation range, but the present embodiment is not limited to this rectangle (square), and may be a polygon or a circle.

[0087] FIG. 6 is a diagram for explaining an application example assuming that the image quality is improved by displaying additional information together with information on the radiation irradiation range in the radiation image capturing system 1000 according to the first embodiment. For example, it is an application example assuming that the image quality is further improved by using the radiation irradiation distribution information in the radiation irradiation range. In FIG. 6, the same components as those shown in FIGS. 1, 3, and 4 are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0088] In FIGS. 6(a) and 6(b), the directions of the anode (+) and the cathode (-) of the radiation generation unit 1010 with respect to the subject H and the radiation imaging unit 1030 are shown. Further, in FIG. 6(c), the relationship between the imaging distance and the irradiation field between the radiation generation unit 1010 and the radiation imaging unit 1030, and the relationship between the relative dose of the radiation R and the distance from the central axis are shown.

[0089] The larger the radiation imaging unit 1030 becomes, the more likely a radiation irradiation distribution will occur. The factors causing the radiation irradiation distribution include the difference in distance from the radiation generation unit 1010 within the radiation imaging unit 1030, the difference between the directions parallel and perpendicular to the anode and cathode of the radiation generation unit 1010, the radiation aperture 1020, the attenuation distribution and scattered radiation distribution within the radiation imaging unit 1030, etc. It is not determined by the specifications of the radiation generation unit 1010 and the radiation imaging unit 1030, but it is necessary to consider the imaging purpose, especially whether to perform image diagnosis using the symmetry of the human body. There are roughly two patterns for the directions of the anode and cathode of the radiation generation unit 1010 with respect to the human body: the longitudinal direction and the transverse direction. The first is the case where it is effective to diagnose an image on the premise of the left - right symmetry of the human body. In such a case, it is desirable to set the directions of the anode and cathode of the radiation generation unit 1010 in the longitudinal direction. This is because if the directions of the anode and cathode of the radiation generation unit 1010 are in the transverse direction, a difference in radiation irradiation between the anode and cathode in the transverse direction may appear, for example, as a difference in density between the left and right lungs, which may cause misdiagnosis or a sense of image discomfort. However, as a drawback, when the directions of the anode and cathode of the radiation generation unit 1010 are in the longitudinal direction, the shading becomes very large. The greater the size of the radiation imaging unit 1030 in the longitudinal direction, the more affected it is. The second is the case where it may not be desirable to have a density difference in the longitudinal direction. For example, in the case of the extremities, it may be a desirable image to set the directions of the anode and cathode of the radiation generation unit 1010 in the transverse direction. Also, in the case of imaging for obtaining quantitative information in the density direction such as the DIP method or BMD, it is also desirable to set the directions of the anode and cathode of the radiation generation unit 1010 in a predetermined direction at a predetermined location. In the present embodiment, it is desirable to display such additional information on the anode (+) and cathode (-) of the radiation generation unit 1010 on the screen 501 shown in FIG. 5(a) (specifically, displayed in the first correction image 520 in FIG. 5(a)) so that a more appropriate correction image can be determined.

[0090] The radiation image capturing system 1000 according to the first embodiment described above includes a radiation image capturing unit 1030 that captures a radiation image based on the incident radiation R. Further, the radiation image capturing system 1000 according to the first embodiment includes radiation irradiation range acquisition units 1061 and 1062 that acquire a radiation irradiation range for imaging 511, which is the irradiation range of the radiation R when the radiation image capturing unit 1030 captures a radiation image. Furthermore, the radiation image capturing system 1000 according to the first embodiment includes a display unit 1170 that can selectively display at least one correction image from a plurality of correction images 520 and 530 having different irradiation conditions of the radiation R based on the radiation irradiation range for imaging 511. According to such a configuration, even when the entire surface of the radiation image capturing unit 1030 cannot be irradiated with the radiation R, it is possible to appropriately correct the captured radiation image.

[0091] Furthermore, the radiation image capturing system 1000 according to the first embodiment includes a radiation irradiation range storage unit 1110 that stores a radiation irradiation range for correction, which is the irradiation range of the radiation R when each correction image is acquired by the radiation image capturing unit 1030. Then, the display unit 1170 can selectively display at least one correction image from the plurality of correction images 520 and 530 based on the radiation irradiation range for imaging 511 and the plurality of radiation irradiation ranges for correction 521 and 531. More specifically, the display unit 1170 displays the radiation irradiation range for imaging 511 in the radiation image capturing unit 1030 and the plurality of radiation irradiation ranges for correction 521 and 531 in the radiation image capturing unit 1030 on the screen 501 so that they can be compared. According to such a configuration, even when the entire surface of the radiation image capturing unit 1030 cannot be irradiated with the radiation R, it is possible to more appropriately correct the captured radiation image.

[0092] (Second Embodiment) Next, a second embodiment will be described. In the description of the second embodiment given below, descriptions of matters common to the above-described first embodiment will be omitted, and matters different from the above-described first embodiment will be described.

[0093] The schematic configuration of the radiation image imaging system according to the second embodiment is the same as the schematic configuration of the radiation image imaging system 1000 according to the first embodiment shown in FIG. 1. In the second embodiment, a form will be described in which the radiation irradiation range is recognized in advance using a camera image captured by the visible light camera 1040.

[0094] FIGS. 7A and 7B are diagrams showing an example of a screen that can be displayed on the display unit 1170 in the radiation image imaging system 1000 according to the second embodiment. In FIGS. 7A and 7B, the same reference numerals are given to the components similar to those shown in FIG. 5, and detailed descriptions thereof are omitted.

[0095] FIG. 7A shows a screen 701 for displaying a camera image captured by the visible light camera 1040, a screen 702 for displaying a radiation image 510, correction images 520 and 530, etc., which are captured images, and a screen 703 for displaying the previous captured image (radiation image). Here, in the present embodiment, it is assumed that the screen 701, the screen 702, and the screen 703 are simultaneously displayed on the display unit 1170. However, in the present disclosure, a form in which the screen 701, the screen 702, and the screen 703 are respectively displayed on different display units (monitors) is also included. Further, in the present embodiment, the screen 702 shown in FIG. 7A has the functions of the display unit 1170 and the operation panel 1160.

[0096] In the second embodiment, it is assumed that the large-sized radiation image capturing unit 1030 is arranged on the entire surface of the lying table. On the screen 701, a camera image is displayed in which a light irradiation range 712 irradiated with light from the light source of the radiation diaphragm 1020 on the radiation image capturing unit 1030 is depicted. The light irradiation range 712 is a range irradiated with light from the light source of the radiation diaphragm 1020 arranged so as to be optically at the same position as the position of the focal point of the radiation R of the radiation generation unit 1010. In the camera image displayed on the screen 701, a radiation image capturing unit region 710 corresponding to the radiation image capturing unit 1030, which is irradiated with light from the light source of the radiation diaphragm 1020 in the light irradiation range 712, is depicted. At this time, on the radiation image capturing unit region 710 of the camera image displayed on the screen 701, A, B, C, and D, which are indicators 711 indicating the arrangement position of the radiation image capturing unit 1030, are depicted. Similarly, on the radiation image 510 displayed on the screen 702, A, B, C, and D, which are indicators 721 indicating the arrangement position of the radiation image capturing unit 1030 and respectively correspond to the indicators 711 (A, B, C, D) depicted in the radiation image capturing unit region 710, are depicted. Also, on the first correction image 520 displayed on the screen 702, A, B, C, and D, which are indicators 722 indicating the arrangement position of the radiation image capturing unit 1030 and respectively correspond to the indicators 711 (A, B, C, D) depicted in the radiation image capturing unit region 710, are depicted. Further, on the second correction image 530 displayed on the screen 702, A, B, C, and D, which are indicators 723 indicating the arrangement position of the radiation image capturing unit 1030 and respectively correspond to the indicators 711 (A, B, C, D) depicted in the radiation image capturing unit region 710, are depicted. Thereby, in the camera image displayed on the screen 701 and the radiation image 510, the first correction image 520, and the second correction image 530 displayed on the screen 702, the arrangement relationship of the radiation image capturing unit 1030 can be grasped. In FIG. 7A, A, B, C, and D of the indicators reflected in the camera image of the screen 701 and the radiation image 510, the correction images 520, and 530 of the screen 702 are provided at the four corners of the radiation image capturing unit 1030, but the present embodiment is not limited thereto. For example, if the arrangement relationship of the radiation image capturing unit 1030 is a symbol that can uniquely determine the direction like a character, it may be provided at one corner.In addition, the location where the product manufacturer name and product name are printed may be utilized and used as an indicator showing the layout relationship of the radiation image capturing unit 1030.

[0097] FIG. 7B shows an application example in which a radiation image capturing unit area 710 corresponding to the radiation image capturing unit 1030 capable of capturing a radiation image of an entire wall surface is set as shown in the camera image displayed on the screen 701. In FIG. 7B, the same components as those shown in FIG. 7A are denoted by the same reference numerals, and detailed descriptions thereof are omitted. As shown in FIG. 7B, when a radiation image can be captured on an entire wall surface as the radiation image capturing unit area 710, the radiation R irradiated from the radiation generating unit 1010 may not be able to irradiate the entire wall surface at once. In such a case, the camera image captured by the visible light camera 1040 attached to the radiation aperture 1020 is displayed on the screen 701. By simultaneously displaying the camera image including the light irradiation range 712 displayed on the screen 701 of FIG. 7B and the correction images 520 and 530 including the radiation irradiation range displayed on the screen 702, an appropriate correction image is selected by the selection 1 button 523 or the selection 2 button 533.

[0098] Next, the processing procedure in the control method of the radiation image capturing system 1000 according to the second embodiment will be described. Here, in the control method of the radiation image capturing system 1000 according to the second embodiment, the processing procedure at the time of factory shipment is the same as that in FIG. 2A, and the processing procedure at the time of installation / periodic inspection is the same as that in FIG. 2B, and thus detailed descriptions thereof are omitted.

[0099] FIG. 8 is a flowchart showing an example of a processing procedure when the radiation imaging system 1000 according to the second embodiment is in use at the installation site. In FIG. 8, a flowchart showing an example of the processing procedure when the radiation imaging system 1000 according to the second embodiment is in use at the installation site is shown as SS_C2. Further, the processing of the flowchart (SS_C2) when the radiation imaging system 1000 is in use at the installation site shown in FIG. 8 can be performed after the processing of the flowchart (SS_B1) at the time of installation / periodic inspection shown in FIG. 2B is completed. In the processing of the flowchart shown in FIG. 8, the same step numbers are assigned to the processing steps similar to those of the flowchart shown in FIG. 2C, and the detailed description thereof is omitted.

[0100] First, in step S401, the radiation imaging system 1000 displays the camera image of the visible light camera 1040 attached to the radiation aperture 1020 on the screen 701 of the display unit 1170.

[0101] Subsequently, in step S402, the radiation imaging system 1000 (for example, the CPU 1140) detects the light irradiation range 712 of the light from the light source of the radiation aperture 1020 from the camera image acquired in step S401. If the light source of the radiation aperture 1020 is not always lit but is designed to be lit only when a predetermined button is pressed, a camera image taken as a still image when the light irradiation range 712 is lit is used. Alternatively, a camera image may be taken as a moving image, and the moving image display may be stopped on the screen 701 where the light irradiation range 712 is lit.

[0102] Subsequently, in the same manner as step S301 in FIG. 2C, the radiation imaging system 1000 displays the gain correction possible region on the display unit 1170. It is desirable that the gain correction possible region in the large radiation imaging unit 1030 is displayed on the display unit 1170.

[0103] Subsequently, in the same manner as step S302 in FIG. 2C, the gain correction data selection unit 1120 selects a gain correction image to be used from among a plurality of gain correction images based on, for example, an operation input on the operation panel 1160.

[0104] Subsequently, in step S403, it is determined whether the light irradiation range 712 obtained in step S402 falls within the radiation irradiation range for correction in the gain correction image selected in step S302. At this time, it is taken into account that the light irradiation range of the light from the light source of the radiation aperture 1020 does not necessarily coincide with the radiation irradiation range and may be offset by about 1 inch. The light irradiation range of the light from the light source of the radiation aperture 1020 may be irradiated slightly wider than the actual radiation emission range so as not to excessively irradiate the radiation R. Therefore, it is desirable to display a screen 502 for calibrating the difference between the radiation irradiation range for correction and the light irradiation range, and to be able to calibrate the light irradiation range via the operation panel 1160.

[0105] As a result of the determination in step S403, if the light irradiation range 712 obtained in step S402 does not fall within the radiation irradiation range for correction in the gain correction image selected in step S302 (S403 / NO), the process returns to step S402. Then, when returning to step S402, after adjusting the radiation aperture 1020, the processes after step S402 are performed again.

[0106] On the other hand, as a result of the determination in step S403, if the light irradiation range 712 obtained in step S402 falls within the radiation irradiation range for correction in the gain correction image selected in step S302 (S403 / YES), the process proceeds to step S303. Since the processes after step S303 are the same as the processes in FIG. 2C, the detailed description thereof is omitted.

[0107] (Third Embodiment) Next, the third embodiment will be described. In the description of the third embodiment described below, descriptions of matters common to the above-described first and second embodiments are omitted, and matters different from the above-described first and second embodiments will be described.

[0108] The schematic configuration of the radiation imaging system according to the third embodiment is the same as that of the radiation imaging system 1000 according to the first embodiment shown in FIG. 1. In the third embodiment, a form of navigation is described in which, using a camera image or the like captured by the visible light camera 1040, the light irradiation range of the light from the light source of the radiation aperture 1020 is made to enter the radiation irradiation range of the correction image listed as a selection candidate in advance.

[0109] FIGS. 9A and 9B are diagrams showing an example of a screen that can be displayed on the display unit 1170 in the radiation imaging system 1000 according to the third embodiment. In FIGS. 9A and 9B, the same reference numerals are given to the components similar to those shown in FIGS. 5, 7A, and 7B, and detailed descriptions thereof are omitted.

[0110] FIG. 9A shows a screen 701 for displaying a camera image captured by the visible light camera 1040, a screen 702 for displaying a radiation image 510, correction images 520 and 530, etc., which are captured images, and a screen 703 for displaying the previous captured image (radiation image). FIG. 9A is a diagram showing an example of a screen display corresponding to FIG. 7A among FIGS. 7A and 7B. In FIG. 7A, a camera image in which the light irradiation range 712 was drawn, captured by the visible light camera 1040, was displayed on the screen 701. On the other hand, in FIG. 9A, on the screen 701, together with the light irradiation range 712, a radiation irradiation range 912 corresponding to the radiation irradiation range (521) of the first correction image 520 currently selected is displayed in an overlay with respect to the light irradiation range 712.

[0111] On the screen 701 shown in FIG. 9A, information 911 indicating the currently selected correction image is displayed so as not to misidentify the currently selected correction image. Also, while looking at the screen 701 shown in FIG. 9A, the user moves the radiation generation unit 1010 to a position where an appropriate camera image can be obtained. On the screen 701 shown in FIG. 9A, the amount of movement (deviation amount) is displayed as navigation information 913. The navigation information 913 includes information indicating whether the position of the current light irradiation range 712 is "OK" or "NG" (in FIG. 9A, "NG"), and information indicating the direction and amount to move (in FIG. 9A, "↓20 cm, →2 cm").

[0112] Also in the screen 702 shown in FIG. 9A, in the first correction image 520, together with its radiation irradiation range (521), a light irradiation range 921 corresponding to the light irradiation range 712 displayed on the screen 701 is displayed in an overlay with respect to the radiation irradiation range (521). Further, as navigation information 922, information indicating whether the position of the current light irradiation range 921 is "OK" or "NG" (in FIG. 9A, "NG"), and information indicating the direction and amount to move (in FIG. 9A, "↑20 cm, →2 cm") are included. Similarly, in the second correction image 530, together with its radiation irradiation range (531), a light irradiation range 931 corresponding to the light irradiation range 712 displayed on the screen 701 is displayed in an overlay with respect to the radiation irradiation range (531). Further, as navigation information 932, information indicating whether the position of the current light irradiation range 921 is "OK" or "NG" (in FIG. 9A, "OK") is included. Thereby, the user can easily grasp the difference between the light irradiation range and the radiation irradiation range of the correction image on a separate axis together with the target radiation image.

[0113] FIG. 9B is a diagram showing an example of a screen display corresponding to FIG. 7B among FIGS. 7A and 7B. In this FIG. 9B, the same components as those shown in FIG. 9A are denoted by the same reference numerals, and detailed description thereof is omitted. As depicted in the camera image displayed on the screen 701 shown in FIG. 9B, when the radiation image capturing unit region 710 corresponding to the radiation image capturing unit 1030 capable of capturing a radiation image of an entire wall surface is considered, the following can be thought of. Specifically, there is a possibility that the position of the radiation R irradiated from the radiation generation unit 1010 is different from the radiation irradiation range for correction used in the previous image. In FIG. 9A, the radiation generation unit 1010 was moved by using the visible light camera 1040 attached to the radiation aperture 1020. On the other hand, in the case where the entire wall surface as in FIG. 9B is the radiation image capturing unit 1030, even if the visible light camera 1040 is installed at a location where the whole can be photographed, it can be used as navigation for the radiation irradiation range of the present disclosure.

[0114] FIG. 10 is a flowchart showing an example of a processing procedure during use at the installation location in the control method of the radiation image capturing system 1000 according to the third embodiment. In FIG. 10, a flowchart showing an example of the processing procedure during use at the installation location in the third embodiment is shown as SS_C3. Also, the processing of the flowchart (SS_C3) during use at the installation location shown in FIG. 10 can be performed after the processing of the flowchart (SS_B1) at the time of installation / periodic inspection shown in FIG. 2B is completed. Also, in the processing of the flowchart shown in FIG. 10, the same step numbers are assigned to the processing steps similar to those of the flowchart shown in FIG. 8, and detailed description thereof is omitted.

[0115] First, similar to step S401 in FIG. 8, the radiation image capturing system 1000 displays the camera image of the visible light camera 1040 attached to the radiation aperture 1020 on the screen 701 of the display unit 1170.

[0116] Subsequently, in the same manner as step S402 in FIG. 8, the radiation image capturing system 1000 (e.g., CPU 1140) detects the light irradiation range 712 of the light from the light source of the radiation aperture 1020 from the camera image acquired in step S401.

[0117] Subsequently, in the same manner as step S301 in FIG. 8 (FIG. 2C), the radiation image capturing system 1000 displays the gain correction available area on the display unit 1170. It is desirable that the gain correction available area in the large radiation image capturing unit 1030 is displayed on the screen of the display unit 1170.

[0118] Subsequently, in the same manner as step S302 in FIG. 8 (FIG. 2C), the gain correction data selection unit 1120 selects the gain correction image to be used from among a plurality of gain correction images, for example, based on an operation input to the operation panel 1160.

[0119] Subsequently, in step S501, for example, the CPU 1140 superimposes and displays the light irradiation range 712 and the radiation irradiation range 912 corresponding to the radiation irradiation range of the gain correction image selected in step S302 in the camera image displayed on the screen 701. At this time, also in the first correction image 520 and the second correction image 530 of the screen 702 shown in FIGS. 9A and 9B, the light irradiation range and the radiation irradiation range are superimposed and displayed so that the influence on the actual radiation image can be easily judged.

[0120] Subsequently, in step S502, for example, the CPU 1140 displays the navigation information. In the example shown in FIG. 9A (the same applies to FIG. 9B), the navigation information 913, the navigation information 922, and the navigation information 932 are displayed.

[0121] Subsequently, in step S503, for example, the CPU 1140 determines whether or not the light irradiation range detected in step S402 is within the radiation irradiation range of the gain correction image selected in step S302 (OK).

[0122] If, as a result of the determination in step S503, the light irradiation range detected in step S402 does not fall within the radiation irradiation range of the gain correction image selected in step S302 (S503 / NO), the process returns to step S402. Then, when returning to step S402, after adjusting the radiation aperture 1020, the processes after step S402 are performed again.

[0123] On the other hand, if, as a result of the determination in step S503, the light irradiation range detected in step S402 falls within the radiation irradiation range of the gain correction image selected in step S302 (S503 / YES), the process proceeds to step S303. Since the processes after step S303 are the same as the processes in FIG. 8 (FIG. 2C), detailed description thereof is omitted.

[0124] In the third embodiment, the display unit 1170 is configured to be able to display and compare the light irradiation range of the light from the light source of the radiation aperture 1020 with respect to the radiation imaging unit 1030 and the plurality of radiation irradiation ranges for correction in the radiation imaging unit 1030 (FIGS. 9A and 9B). Further, the display unit 1170 further displays information indicating whether or not the light irradiation range is included in the radiation irradiation range for correction (the "NG" or "OK" in the navigation information 913, 922, and 932 in FIGS. 9A and 9B). Furthermore, when the light irradiation range is not included in the radiation irradiation range for correction, the display unit 1170 is configured to perform the following display. Specifically, the display unit 1170 further displays information indicating the amount of deviation with respect to the radiation irradiation range for correction of the excess range, which is the portion of the light irradiation range not included in the radiation irradiation range for correction (the arrows in the navigation information 913, 922, and 932 in FIGS. 9A and 9B). According to such a configuration, in addition to the effects in the first embodiment, the difference between the light irradiation range and the radiation irradiation range of the correction image can be easily grasped on a separate axis.

[0125] (Fourth Embodiment) Next, a fourth embodiment will be described. In the description of the fourth embodiment below, descriptions of matters common to the above-described first to third embodiments will be omitted, and matters different from the above-described first to third embodiments will be described.

[0126] The schematic configuration of the radiation image imaging system according to the fourth embodiment is the same as the schematic configuration of the radiation image imaging system 1000 according to the first embodiment shown in FIG. 1. In the fourth embodiment, a form in which the radiation irradiation range of the correction image is inappropriate after imaging the radiation image of the subject H will be described.

[0127] FIG. 11A is a diagram showing a first configuration example of the control system of the radiation image imaging system 1000 according to the fourth embodiment. In FIG. 11A, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0128] The control system shown in FIG. 11A includes a radiation generation unit 1010, a radiation image imaging unit 1030, and a general control unit 1101 including a control PC including the operation panel 1160, the CPU 1140, and the main memory 1150 shown in FIG. 1.

[0129] In the control system shown in FIG. 11A, when a shooting preparation start request is issued from the general control unit 1101 including the operation panel 1160 to the radiation image imaging unit 1030, the radiation image imaging unit 1030 performs a preparation drive. Then, when the preparation is completed, the radiation image imaging unit 1030 issues a permission signal for irradiating the radiation R to the radiation generation unit 1010. The radiation generation unit 1010 starts irradiating the radiation R based on the reception of the permission signal and the radiation irradiation control from the general control unit 1101 by the user's pressing operation of the irradiation switch. The radiation image imaging unit 1030 acquires the radiation irradiation range, for example, by starting non-destructive reading of the radiation image signal. When the radiation irradiation range of the correction image is narrower than the radiation irradiation range of the radiation image during shooting, the radiation image imaging unit 1030 issues a stop signal for irradiating the radiation R to the radiation generation unit 1010. The radiation generation unit 1010 stops irradiating the radiation R immediately upon receiving the stop signal.

[0130] FIG. 11B is a diagram showing a second configuration example of the control system of the radiation image imaging system 1000 according to the fourth embodiment. Specifically, FIG. 11B is a diagram showing a configuration example of the control system of the radiation image imaging unit 1030 according to the fourth embodiment. In this FIG. 11B, the same components as those shown in FIGS. 1 and 11A are denoted by the same reference numerals, and detailed description thereof is omitted.

[0131] The control system of the radiation image imaging unit 1030 shown in FIG. 11B includes an MPU (CPU), a timer / minute cycle, a watchdog timer, an Ethernet communication IF, and an input / output port. In the control system of the radiation image imaging unit 1030 shown in FIG. 11B, in order to make the stop signal react as quickly as possible, it is desirable that the clock input to the timer / minute cycle has a high frequency. If there is no reaction for a certain period of time, there may be some error in the real-time processing, so a watchdog timer is installed. A non-maskable interrupt (NMI) of the MPU (CPU) is made to the watchdog timer. Thereby, even when a shooting preparation start request from the operation panel 1160 is input to the radiation image imaging unit 1030, a warning signal indicating that an error has occurred in the real-time processing is output to the operation panel 1160. The image data acquired by the radiation image imaging unit 1030 is output via a gigabit Ethernet communication IF or the like. The signals of the shooting preparation start request, the stop signal, the permission signal, and the warning signal are input and output via the input / output port.

[0132] FIG. 12 is a flowchart showing an example of a processing procedure in the control method of the radiation image imaging system 1000 according to the fourth embodiment. Specifically, FIG. 12 is a flowchart showing an example of a processing procedure in the control method in the control system of the radiation image imaging system 1000 according to the fourth embodiment shown in FIG. 11A (FIG. 11B may also be included).

[0133] First, in step S601, the radiation image capturing unit 1030 sets the count value of the timer. The count value of the timer after setting the initial value is decremented by a timer that is relaxed in a minute cycle in response to the clock input.

[0134] Subsequently, in step S602, the radiation image capturing unit 1030 receives the input of a signal for a shooting preparation start request. Here, a signal for a shooting preparation start request is input from the overall control unit 1101 including the operation panel 1160 to the radiation image capturing unit 1030.

[0135] Subsequently, in step S603, the radiation image capturing unit 1030 starts the shooting preparation drive. For example, the radiation image capturing unit 1030 starts a preparation drive such as color reading of the signal.

[0136] Subsequently, in step S604, the radiation image capturing unit 1030 outputs a permission signal for irradiation with radiation R to the radiation generation unit 1010. When the shooting preparation drive has been performed for a predetermined time or a predetermined number of times and a stable radiation image can be captured, the radiation image capturing unit 1030 outputs a permission signal for irradiation with radiation R to the radiation generation unit 1010.

[0137] Subsequently, in step S605, the radiation generation unit 1010 starts irradiation with radiation R based on the permission signal from the radiation image capturing unit 1030 and the radiation irradiation control from the overall control unit 1101 due to the pressing operation of the user's irradiation switch.

[0138] Subsequently, in step S606, the radiation image capturing unit 1030 performs initial acquisition of the radiation irradiation range by non-destructive reading. Here, acquisition of the radiation irradiation range during radiation irradiation has been described by non-destructive reading, but the radiation irradiation range may be acquired by reading a bias signal or the like only for a predetermined line.

[0139] Subsequently, in step S607, the radiation image capturing unit 1030 determines whether the radiation irradiation range obtained in step S606 is within the radiation irradiation range of the correction image (OK).

[0140] As a result of the determination in step S607, if the radiation irradiation range obtained in step S606 is within the radiation irradiation range of the correction image (S607 / YES), the process proceeds to step S608. When the process proceeds to step S608, the radiation image capturing unit 1030 continues the irradiation of the radiation R by the radiation generation unit 1010.

[0141] On the other hand, as a result of the determination in step S607, if the radiation irradiation range obtained in step S606 is not within the radiation irradiation range of the correction image (S607 / NO), the process proceeds to step S609. When the process proceeds to step S609, the radiation image capturing unit 1030 outputs a stop signal for the irradiation of the radiation R to the radiation generation unit 1010. For example, when the radiation irradiation range obtained in S606 is larger than the radiation irradiation range of the correction image, particularly when the region of interest is larger than the radiation irradiation range of the correction image, the radiation image capturing unit 1030 outputs a stop signal for the irradiation of the radiation R to the radiation generation unit 1010. Thereafter, for example, the radiation generation control unit 1070 performs control to stop the irradiation of the radiation R from the radiation generation unit 1010 based on the stop signal for the irradiation of the radiation R output from the radiation image capturing unit 1030.

[0142] When the process of step S608 is completed, or when the process of step S609 is completed, the process proceeds to step S610. When the process proceeds to step S610, the radiation generation unit 1010 ends the irradiation of the radiation R. When the irradiation of the radiation R ends, the radiation image obtained by the radiation image capturing unit 1030 is output to the overall control unit 1101 including the control PC via the Ethernet communication IF or the like.

[0143] Subsequently, in step S611, for example, the overall control unit 1101 acquires the radiation irradiation range from the received radiation image. Here, for example, the radiation irradiation range is acquired by image analysis using the radiation image as an input.

[0144] Subsequently, in step S612, for example, the overall control unit 1101 determines whether the radiation irradiation range of the radiation image acquired in step S611 is wider (OK) than the radiation irradiation range of the correction image. As described with reference to FIG. 5, since there may be some error between the light irradiation range and the radiation irradiation range, the determination is made based on the finally acquired radiation image.

[0145] As a result of the determination in step S612, if the radiation irradiation range of the radiation image acquired in step S611 is not wider than the radiation irradiation range of the correction image (S612 / NO), the process proceeds to step S613. When the process proceeds to step S613, for example, the overall control unit 1101 outputs an alarm signal related to the warning. When this alarm signal is output, the user grasps that the correction image is inappropriate, but if the subject H is photographed again, unnecessary radiation R will be irradiated.

[0146] Subsequently, in step S614, for example, the overall control unit 1101 selects and acquires a new correction image (gain correction image) based on, for example, an operation input on the operation panel 1160. In order to avoid irradiation of unnecessary radiation R, a new correction image (gain correction image) is selected and acquired after photographing the subject H. For example, the correction image (gain correction image) at the time of factory shipment is selected and acquired. Also, the appropriateness of the correction image can be determined by outputting an alarm signal immediately after photographing the subject H. Therefore, by acquiring the correction image as it is without operating the radiation generation unit 1010, the radiation aperture 1020, or the radiation image capturing unit 1030 immediately after photographing the subject H, the latest correction image can be acquired.

[0147] When the process of step S614 ends, or when it is determined in step S612 that the radiation irradiation range of the radiation image acquired in S611 is wider than the radiation irradiation range of the correction image (S612 / YES), the process proceeds to step S615. When the process proceeds to step S615, for example, the overall control unit 1101 corrects (gain-corrects) the radiation image obtained by imaging using the currently selected correction image (gain correction image).

[0148] Subsequently, in step S616, for example, the overall control unit 1101 outputs the radiation image for which the image correction process has been performed.

[0149] FIG. 13 is a flowchart showing an example of a processing procedure when in use at the installation location in the control method of the radiation image imaging system 1000 according to the fourth embodiment. In FIG. 13, a flowchart showing an example of the processing procedure when in use at the installation location in the fourth embodiment is shown as SS_C4. Further, the processing of the flowchart (SS_C4) showing the use at the installation location shown in FIG. 13 can be performed after the processing of the flowchart (SS_B1) showing the installation / periodic inspection shown in FIG. 2B is completed. Also, in the processing of the flowchart shown in FIG. 13, the same step numbers are assigned to the processing steps similar to those in the flowchart shown in FIG. 2C, and detailed descriptions thereof are omitted.

[0150] First, similar to step S301 in FIG. 2C, the radiation image imaging system 1000 displays the gain correction possible region on the display unit 1170. It is desirable that the gain correction possible region in the large radiation image imaging unit 1030 is displayed on the display unit 1170.

[0151] Subsequently, similar to step S302 in FIG. 2C, the gain correction data selection unit 1120 selects the gain correction image to be used from among a plurality of gain correction images, for example, based on an operation input to the operation panel 1160.

[0152] Subsequently, similar to step S303 in FIG. 2C, the radiation image imaging system 1000 performs radiation imaging of the subject H.

[0153] Subsequently, in the same manner as step S304 in FIG. 2C, the image correction unit 1090 performs image processing such as gain-correcting the radiation image captured in step S304 using the gain correction image selected in step S302.

[0154] Subsequently, in the same manner as step S305 in FIG. 2C, the display unit 1170 performs image display for confirmation of the radiation image (captured image) that has been image-processed in step S304.

[0155] Subsequently, in step S701, for example, the CPU 1140 or the gain correction determination unit 1130 determines whether it is okay with the currently selected gain correction image based on, for example, an operation input on the operation panel 1160. Here, in the process of step S306 in FIG. 2C, the gain correction image used was one that had been acquired and stored in the past (including the one stored in step S108 in FIG. 2A). In contrast, in the process of step S701 in FIG. 13, it also includes the gain correction image newly acquired in step S704 described later.

[0156] As a result of the determination in step S701, if it is not okay (NG) with the currently selected gain correction image (S701 / NO), the process proceeds to step S702. When the process proceeds to step S702, the radiation image capturing system 1000 determines that there is no appropriate gain correction image that can be selected, and warns the display unit 1170 to that effect.

[0157] Subsequently, in step S703, the radiation image capturing system 1000 temporarily stores the image before gain correction (radiation image) in, for example, the storage unit 1100 or the like.

[0158] Subsequently, in step S704, the radiation image capturing system 1000 acquires a new gain correction image. Here, it is desirable that the new gain correction image be acquired using the same geometric arrangement and radiation irradiation conditions (focal spot size, kVp, mAs, etc.) as the imaging of the subject H in step S303.

[0159] Subsequently, in step S705, the radiation image capturing system 1000 stores the new gain correction image acquired in step S704 in, for example, the second gain correction data storage unit 1052. Then, the process returns to step S304, and the processes after step S304 are performed using the new gain correction image acquired in step S704.

[0160] Also, as a result of the determination in step S701, if the currently selected gain correction image is acceptable (S701 / YES), the process proceeds to step S309. When the process proceeds to step S309, the radiation image capturing system 1000 stores the captured radiation image.

[0161] In the fourth embodiment, compared with the above-described first embodiment, when the subject H is imaged at the outermost side within the effective pixel range of the large radiation image capturing unit 1030, there is a possibility that the image quality is improved. In the above-described first embodiment, the gain correction image at the time of factory shipment stored in step S108 of FIG. 2A often aligns the center of the radiation generation unit 1010 with the center of the large radiation image capturing unit 1030. In contrast, in the fourth embodiment, in step S704 of FIG. 13, the new gain correction image can be acquired using the same geometric arrangement and radiation irradiation conditions (focal spot size, kVp, mAs, etc.) as the imaging of the subject H. This is because both the geometric conditions and the radiation irradiation conditions are close between the actual imaging of the subject H and the gain correction image to be used. Therefore, when imaging is performed at a position close to the edge within the effective pixel range of the large radiation image capturing unit 1030, the fourth embodiment may be more appropriate.

[0162] In the radiation image capturing system 1000 according to the fourth embodiment described above, the display unit 1170 performs a warning display when there is no appropriate selectable gain correction image (S702 in FIG. 13). Also, in the radiation image capturing system 1000 according to the fourth embodiment, the radiation generation control unit 1070 performs control to stop the irradiation of the radiation when the radiation irradiation range for imaging is inappropriate (S609 in FIG. 12).

[0163] According to the radiation imaging system 1000 according to the fourth embodiment, similar to the first embodiment, even when the entire surface of the radiation imaging unit 1030 cannot be irradiated with radiation R, it is possible to appropriately correct the captured radiation image.

[0164] (Fifth Embodiment) Next, the fifth embodiment will be described. In the description of the fifth embodiment described below, descriptions of matters common to the above-described first to fourth embodiments will be omitted, and matters different from the above-described first to fourth embodiments will be described.

[0165] The schematic configuration of the radiation imaging system according to the fifth embodiment is the same as the schematic configuration of the radiation imaging system 1000 according to the first embodiment shown in FIG. 1. In the fifth embodiment, it is a form in which an application example of the radiation imaging system 1000 is illustrated.

[0166] FIG. 14 is a diagram showing an application example of the radiation imaging system 1000 according to the fifth embodiment. The radiation imaging system 1000-1 according to the first application example of the fifth embodiment applies the radiation imaging system 1000 according to the above-described first to fourth embodiments to a chest imaging device. The radiation imaging system 1000-2 according to the second application example of the fifth embodiment applies the radiation imaging system 1000 according to the above-described first to fourth embodiments to a bucky upright imaging table. The radiation imaging system 1000-3 according to the third application example of the fifth embodiment applies the radiation imaging system 1000 according to the above-described first to fourth embodiments to a bucky table (with a top plate that can be raised and lowered). The radiation imaging system 1000-4 according to the fourth application example of the fifth embodiment applies the radiation imaging system 1000 according to the above-described first to fourth embodiments to a DU alarm type bucky imaging device.

[0167] (Other Embodiments) In the above-described embodiments, an example in which a gain correction image is applied as an example of the correction image in the present disclosure has been described. However, in the present disclosure, the present disclosure is not limited to this gain correction image, and correction images related to other image processes can also be applied.

[0168] The present disclosure can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and causing one or more processors in a computer of the system or device to read and execute the program. Further, it can also be realized by a circuit (for example, ASIC) that realizes one or more functions. This program and a computer-readable storage medium storing the program are included in the present disclosure.

[0169] Note that the above-described embodiments of the present disclosure are merely examples of specific embodiments for implementing the present disclosure, and the technical scope of the present disclosure should not be construed in a limited manner by these. That is, the present disclosure can be implemented in various forms without departing from its technical idea or its main features.

[0170] Embodiments of the present disclosure include the following configurations, methods, and programs. [Configuration 1] A radiation image capturing unit that captures a radiation image based on incident radiation, An acquisition unit that acquires a radiation irradiation range for imaging, which is an irradiation range of the radiation when the radiation image is captured by the radiation image capturing unit, A display unit that can selectively display at least one correction image from a plurality of correction images having different irradiation conditions of the radiation based on the radiation irradiation range for imaging, A radiation image capturing system, characterized by including the above. [Configuration 2] The radiation image capturing system further includes a storage unit that stores a radiation irradiation range for correction, which is an irradiation range of the radiation when each correction image of the plurality of correction images is acquired by the radiation image capturing unit, The display unit can display and select at least one correction image from the plurality of correction images based on the radiation irradiation range for imaging and the plurality of radiation irradiation ranges for correction in the plurality of correction images. The radiation image capturing system according to Configuration 1, characterized in that. [Configuration 3] The radiation irradiation range for imaging is obtained by analyzing the radiation image. The radiation irradiation range for correction is obtained by analyzing the correction image. The radiation image capturing system according to Configuration 2, characterized in that. [Configuration 4] At least one of the radiation irradiation range for imaging and the radiation irradiation range for correction is Obtained using one or more pieces of information among information on the focal position of the radiation generation unit that generates the radiation, information on the relative position between the radiation generation unit and the radiation image capturing unit, information on the relative angle between the radiation generation unit and the radiation image capturing unit, information on the imaging distance between the radiation generation unit and the radiation image capturing unit, And information on the aperture opening degree of the radiation aperture provided between the radiation generation unit and the radiation image capturing unit. The radiation image capturing system according to Configuration 2 or 3, characterized in that. [Configuration 5] The display unit can display the radiation irradiation range for imaging in the radiation image capturing unit and the plurality of radiation irradiation ranges for correction in the radiation image capturing unit in a comparable manner. The radiation image capturing system according to any one of Configurations 2 to 4, characterized in that. [Configuration 6] The display unit further displays at least one piece of information among the anode and the cathode of the radiation generation unit that generates the radiation. The radiation image capturing system according to Configuration 5, characterized in that. [Configuration 7] A light source is provided between the radiation generation unit that generates the radiation and the radiation imaging unit, and further includes a radiation diaphragm for adjusting the irradiation field of the radiation. The display unit further displays the light irradiation range, which is the range of light from the light source of the radiation diaphragm with respect to the radiation imaging unit, and the plurality of radiation irradiation ranges for correction in the radiation imaging unit in a comparable manner. The radiation imaging system according to Configuration 5 or 6, characterized in that. [Configuration 8] It further has a camera attached to the radiation diaphragm. The light irradiation range is displayed as a camera image obtained by photographing the radiation imaging unit irradiated with the light by the camera. The radiation imaging system according to Configuration 7, characterized in that. [Configuration 9] The plurality of radiation irradiation ranges for correction are displayed as the plurality of correction images. An index indicating the arrangement position of the radiation imaging unit is drawn on the camera image and the plurality of correction images. The radiation imaging system according to Configuration 8, characterized in that. [Configuration 10] The display unit further displays information indicating whether or not the light irradiation range is included in the radiation irradiation range for correction. The radiation imaging system according to any one of Configurations 7 to 9, characterized in that. [Configuration 11] When the light irradiation range is not included in the radiation irradiation range for correction, the display unit, together with information indicating that, Further displays information indicating the amount of deviation of the excess range, which is the portion of the light irradiation range not included in the radiation irradiation range for correction, with respect to the radiation irradiation range for correction. The radiation imaging system according to any one of Configurations 7 to 10, characterized in that. [Configuration 12] The display unit further displays a screen for calibrating the light irradiation range. The radiation image imaging system according to any one of configurations 7 to 11, characterized in that... [Configuration 13] When there is no appropriate correction image that can be selected, the display unit performs a warning display. The radiation image imaging system according to any one of configurations 1 to 12, characterized in that... [Configuration 14] When the radiation irradiation range for imaging is not appropriate, it further has a control unit that performs control to stop the irradiation of the radiation. The radiation image imaging system according to any one of configurations 1 to 13, characterized in that... [Configuration 15] It further has a correction unit that corrects the radiation image using the correction image selected from the at least one correction image that is selectably displayed by the display unit. The radiation image imaging system according to any one of configurations 1 to 14, characterized in that... [Configuration 16] The correction image is a gain correction image for correcting the difference in gain of the radiation image imaging unit. The radiation image imaging system according to any one of configurations 1 to 15, characterized in that... [Configuration 17] The radiation image imaging unit has a rectangular effective pixel range with a long side length of 18 inches or more or a diagonal length of 25 inches or more. The radiation image imaging system according to any one of configurations 1 to 16, characterized in that... [Method 1] A control method for a radiation image imaging system including a radiation image imaging unit that captures a radiation image based on incident radiation, comprising: An acquisition step of acquiring a radiation irradiation range for imaging, which is the radiation irradiation range when the radiation image is captured in the radiation image imaging unit; A display step of selectably displaying at least one correction image from a plurality of correction images with different radiation irradiation conditions based on the radiation irradiation range for imaging; A control method for a radiation imaging system, characterized by having [Program 1] A program for causing a computer to execute a control method for a radiation imaging system including a radiation imaging unit that captures a radiation image based on incident radiation, an acquisition step of acquiring a radiation irradiation range for imaging, which is the irradiation range of the radiation when the radiation image is captured by the radiation imaging unit; a display step of displaying at least one correction image selectable from a plurality of correction images having different radiation irradiation conditions based on the radiation irradiation range for imaging; A program for causing a computer to execute.

Explanation of Signs

[0171] 1000: Radiation imaging system, 1010: Radiation generation unit, 1020: Radiation aperture, 1030: Radiation imaging unit, 1040: Visible light camera, 1051: First gain correction data storage unit, 1052: Second gain correction data storage unit, 1061: First radiation irradiation range acquisition unit, 1062: Second radiation irradiation range acquisition unit, 1070: Radiation generation control unit, 1080: Data collection unit, 1090: Image correction unit, 1091: First preprocessing unit, 1092: Second preprocessing unit, 1093: Image processing unit, 1100: Storage unit, 1110: Radiation irradiation range storage unit, 1120: Gain correction data selection unit, 1130: Gain correction determination unit, 1140: CPU, 1150: Main memory, 1160: Operation panel, 1170: Display unit, 1180: Bus, H: Subject, R: Radiation

Claims

1. A radiation image capturing unit that captures a radiation image based on incident radiation; An acquisition unit that acquires a radiation irradiation range for imaging, which is the irradiation range of the radiation when the radiation image is captured by the radiation image capturing unit; A display unit that displays at least one correction image selectable from a plurality of correction images having different radiation irradiation conditions based on the radiation irradiation range for imaging; A radiation image capturing system, characterized by comprising the above.

2. The radiation image capturing system further includes a storage unit that stores a radiation irradiation range for correction, which is the irradiation range of the radiation when each correction image of the plurality of correction images is acquired by the radiation image capturing unit, and the display unit displays the at least one correction image selectable from the plurality of correction images based on the radiation irradiation range for imaging and the plurality of radiation irradiation ranges for correction in the plurality of correction images. The radiation image capturing system according to claim 1, characterized by the above.

3. The radiation irradiation range for imaging is acquired by image analysis of the radiation image, and the radiation irradiation range for correction is acquired by image analysis of the correction image. The radiation image capturing system according to claim 2, characterized by the above.

4. At least one of the radiation irradiation range for imaging and the radiation irradiation range for correction is acquired using one or more pieces of information among information on the focal position of a radiation generation unit that generates the radiation, information on the relative position between the radiation generation unit and the radiation image capturing unit, information on the relative angle between the radiation generation unit and the radiation image capturing unit, information on the imaging distance between the radiation generation unit and the radiation image capturing unit, and information on the aperture opening of a radiation aperture provided between the radiation generation unit and the radiation image capturing unit. The radiation image capturing system according to claim 2, characterized by the above.

5. The display unit displays the radiation irradiation range for imaging in the radiation image capturing unit and the plurality of radiation irradiation ranges for correction in the radiation image capturing unit in a comparable manner. The radiation image capturing system according to claim 2, characterized by the above.

6. The display unit further displays at least one piece of information among the anode and the cathode of the radiation generation unit that generates the radiation. The radiation image capturing system according to claim 5, characterized by the above.

7. A light source is provided between the radiation generation unit that generates the radiation and the radiation image capture unit, and further includes a radiation aperture for adjusting the irradiation field of the radiation. The display unit is further configured to be able to compare and display a light irradiation range, which is a range of light from the light source of the radiation aperture with respect to the radiation image capture unit, and the plurality of radiation irradiation ranges for correction in the radiation image capture unit. The radiation image capture system according to claim 5, characterized in that.

8. It further includes a camera attached to the radiation aperture. The light irradiation range is displayed as a camera image obtained by photographing the radiation image capture unit irradiated with the light by the camera. The radiation image capture system according to claim 7, characterized in that.

9. The plurality of radiation irradiation ranges for correction are displayed as the plurality of correction images. An index indicating the arrangement position of the radiation image capture unit is drawn in the camera image and the plurality of correction images. The radiation image capture system according to claim 8, characterized in that.

10. The display unit further displays information indicating whether or not the light irradiation range is included in the radiation irradiation range for correction. The radiation image capture system according to claim 7, characterized in that.

11. When the light irradiation range is not included in the radiation irradiation range for correction, the display unit further displays information indicating that, and information indicating the deviation amount of the light irradiation range that is not included in the radiation irradiation range for correction with respect to the radiation irradiation range for correction of the excess range. The radiation image capture system according to claim 7, characterized in that.

12. The display unit further displays a screen for calibrating the light irradiation range. The radiation image capture system according to claim 7, characterized in that.

13. When there is no selectable appropriate correction image, the display unit performs a warning display. The radiation image capture system according to claim 1, characterized in that.

14. It further includes a control unit that performs control to stop the irradiation of the radiation when the radiation irradiation range for imaging is not appropriate. The radiation image capture system according to claim 1, characterized in that.

15. It further includes a correction unit that corrects the radiation image using the correction image selected from the at least one correction image selectively displayed by the display unit. The radiation imaging system according to claim 1, characterized in that...

16. The correction image is a gain correction image for correcting the difference in gain of the radiation imaging unit. The radiation imaging system according to claim 1, characterized in that...

17. The radiation imaging unit has a rectangular effective pixel range with a long side length of 18 inches or more or a diagonal length of 25 inches or more. The radiation imaging system according to claim 1, characterized in that...

18. A control method for a radiation imaging system including a radiation imaging unit that captures a radiation image based on incident radiation, the method comprising: An acquisition step of acquiring a radiation irradiation range for imaging, which is the radiation irradiation range when the radiation image is captured in the radiation imaging unit; A display step of displaying at least one correction image selectable from a plurality of correction images having different radiation irradiation conditions based on the radiation irradiation range for imaging; A control method for a radiation imaging system, characterized by comprising the above steps.

19. A program for causing a computer to execute a control method for a radiation imaging system including a radiation imaging unit that captures a radiation image based on incident radiation, the program comprising: An acquisition step of acquiring a radiation irradiation range for imaging, which is the radiation irradiation range when the radiation image is captured in the radiation imaging unit; A display step of displaying at least one correction image selectable from a plurality of correction images having different radiation irradiation conditions based on the radiation irradiation range for imaging; A program for causing a computer to execute the above steps.

Images