Control device, control device operation method, and control program

Abstract

The CPU of this control device obtains the elapsed time since a contrast medium has been injected into the breast, of which a radiological image is captured by a mammography device, and obtains a low-energy image captured by the mammography device by irradiating the breast with a contrast medium injected with the radiation of a first energy, and a high-energy image captured by the mammography device by irradiating the breast with the contrast medium injected with the radiation of a second energy higher than the first energy. The CPU generates a difference image showing a difference between the low-energy image and the high-energy image. The CPU determines whether or not to recapture a high-energy image of the breast with the contrast medium injected, on the basis of the analysis result regarding the amount of contrast performed on the difference image and the elapsed time.

Description

[Technical field]

[0001] The present disclosure relates to a control device, a control method, and a control program. [Background technology]

[0002] A technique is known in which a contrast imaging is performed on a subject injected with a contrast agent, in which radiation with different energies is radiated to capture a low-energy image and a high-energy image, and a difference image is generated showing the difference between the high-energy image and the low-energy image, thereby generating a radiation image in which the contrast agent is emphasized. It is desired to perform contrast imaging in a state in which the contrast agent has sufficiently penetrated the subject, and it is desired to capture at least a high-energy image at an appropriate timing. For this reason, a technique is known for controlling the timing of contrast imaging. For example, Japanese Patent Application Laid-Open No. 2000-175900 describes a technique for starting an examination scan of a subject based on a change in CT (Computed Tomography) value of a region of interest in a prescan after the contrast agent is injected. Summary of the Invention [Problem to be solved by the invention]

[0003] However, the ease of penetration of the contrast agent, i.e., the speed at which the contrast agent penetrates, may differ depending on the subject, etc. For this reason, it is difficult to specify an appropriate imaging timing, and even the technique described in JP-A-2000-175900 may not be sufficient in some cases.

[0004] The present disclosure has been made in consideration of the above circumstances, and provides a control device, a control method, and a control program that are capable of capturing high-energy images at appropriate timing in contrast imaging. [Means for solving the problem]

[0005] A control device of a first aspect of the present disclosure includes at least one processor, which obtains the elapsed time since a contrast agent is injected into a subject whose radiographic image is to be captured by a radiographic imaging device, obtains a low-energy image captured by the radiographic imaging device by irradiating the subject with the contrast agent injected with radiation of a first energy, and a high-energy image captured by the radiographic imaging device by irradiating the subject with the contrast agent injected with radiation of a second energy higher than the first energy, generates a difference image showing the difference between the low-energy image and the high-energy image, and determines whether or not to re-capture a high-energy image of the subject with the contrast agent injected based on the results of an analysis of the amount of contrast performed on the difference image and the elapsed time.

[0006] A control device according to a second aspect of the present disclosure is the control device according to the first aspect, wherein when it is determined that re-imaging is to be performed, the processor derives the timing to perform re-imaging based on the analysis result and the elapsed time.

[0007] A control device according to a third aspect of the present disclosure is the control device according to the second aspect, wherein the processor controls the radiographic image capturing device to recapture a high-energy image at the derived timing for recapturing.

[0008] A control device of a fourth aspect of the present disclosure is a control device of any one of the first to third aspects, in which the processor determines that re-imaging should not be performed regardless of the elapsed time if the contrast of the region of interest in the difference image is equal to or greater than a predetermined threshold.

[0009] A control device of a fifth aspect of the present disclosure is a control device of any one of the first to fourth aspects, in which the processor determines not to perform re-imaging if the contrast of the region of interest in the difference image is less than a predetermined threshold and the elapsed time is equal to or greater than the threshold time.

[0010] A control device of a sixth aspect of the present disclosure is a control device of any one of the first to fourth aspects, in which the processor determines that re-imaging should be performed when the contrast of the region of interest in the difference image is less than a predetermined threshold and the elapsed time is less than a threshold time.

[0011] A control device of a seventh aspect of the present disclosure is a control device of the fifth or sixth aspect, wherein the threshold time is a time that depends on at least one of the type of contrast agent, the subject's blood flow, the subject's height, the subject's weight, and the type of object of interest.

[0012] A control device according to an eighth aspect of the present disclosure is the control device according to the fifth or sixth aspect, wherein the subject is a breast, and the threshold time is a time according to the amount of mammary gland in the breast.

[0013] A control device of a ninth aspect of the present disclosure is a control device of any one of the first to eighth aspects, in which, when a processor specifies that re-imaging is to be performed, it obtains a re-imaging high-energy image using a radiation image, and generates a re-imaging difference image showing the difference between the low-energy image and the re-imaging high-energy image.

[0014] A control device of a tenth aspect of the present disclosure is a control device of any one of the first to eighth aspects, wherein when a processor specifies that re-capture will be performed, the processor also specifies that a low-energy image will be re-captured, and generates a re-capture difference image showing the difference between the re-captured low-energy image and the re-captured high-energy image.

[0015] A control device of an eleventh aspect of the present disclosure is a control device of the ninth or tenth aspect, in which a processor performs the same image processing on the difference image and the re-captured difference image to highlight the area of ​​interest, and displays the image-processed difference image and the re-captured difference image.

[0016] A control device of a twelfth aspect of the present disclosure is a control device of any one of the ninth to eleventh aspects, in which the processor further displays contrast amount information regarding the contrast amount of the same region in each of the difference image and the re-captured difference image.

[0017] A control device according to a thirteenth aspect of the present disclosure is the control device according to any one of the first to twelfth aspects, in which the subject is a breast, and the radiation image capturing device is a mammography device.

[0018] In addition, a control method of a fourteenth aspect of the present disclosure is a method for a computer to execute a process of obtaining an elapsed time since a contrast agent is injected into a subject whose radiographic image is to be captured by a radiographic imaging device, obtaining a low-energy image captured by the radiographic imaging device by irradiating the subject whose radiographic imaging device has been injected with the contrast agent with radiation of a first energy, and a high-energy image captured by the radiographic imaging device by irradiating the subject whose radiographic imaging device has been injected with the contrast agent with radiation of a second energy higher than the first energy, generating a difference image showing the difference between the low-energy image and the high-energy image, and determining whether or not to re-capture a high-energy image of the subject whose radiographic imaging device has been injected with the contrast agent based on the results of an analysis of the amount of contrast performed on the difference image and the elapsed time.

[0019] In addition, a control program of a fifteenth aspect of the present disclosure causes a computer to execute a process of acquiring an elapsed time since a contrast agent is injected into a subject whose radiographic image is to be captured by a radiographic imaging device, acquiring a low-energy image captured by the radiographic imaging device by irradiating the subject whose radiographic image is injected with the contrast agent with radiation of a first energy, and acquiring a high-energy image captured by the radiographic imaging device by irradiating the subject whose radiographic image is injected with the contrast agent with radiation of a second energy higher than the first energy, generating a difference image showing the difference between the low-energy image and the high-energy image, and determining whether or not to re-capture a high-energy image of the subject whose radiographic image is injected with the contrast agent based on the results of an analysis of the amount of contrast performed on the difference image and the elapsed time. Effect of the Invention

[0020] According to the present disclosure, in contrast imaging, high-energy images can be captured at appropriate timing. [Brief description of the drawings]

[0021] [Figure 1] 1 is a configuration diagram illustrating an example of the overall configuration of a radiation image capturing system according to an embodiment; [Diagram 2] 1 is a side view showing an example of the appearance of a mammography apparatus according to an embodiment. [Diagram 3] FIG. 2 is a block diagram illustrating an example of a configuration of a console according to an embodiment. [Figure 4] FIG. 2 is a functional block diagram illustrating an example of functions of a console according to an embodiment. [Diagram 5] 4 is a flowchart showing an example of a flow of contrast imaging by the radiation image capturing system of the embodiment. [Figure 6A] 11 is a time chart showing an example of contrast imaging when re-imaging is performed. [Figure 6B] 11 is a time chart showing an example of contrast imaging without re-imaging. [Figure 7] 10 is a flowchart showing an example of the flow of a contrast imaging control process executed in contrast imaging. [Figure 8] 11 is a flowchart showing an example of the flow of a difference image display process executed in contrast imaging. [Figure 9] 13 is a diagram showing an example of a state in which a difference image and contrast amount information are displayed on a display unit. FIG. [Figure 10] 11 is a time chart showing an example of re-imaging of only high-energy images; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiment.

[0023] First, an example of the overall configuration of the radiation image capturing system of this embodiment will be described. Fig. 1 shows a configuration diagram showing an example of the overall configuration of the radiation image capturing system 1 of this embodiment. As shown in Fig. 1, the radiation image capturing system 1 of this embodiment includes a mammography device 10 and a console 12. The mammography device 10 of this embodiment is an example of the radiation image capturing device of the present disclosure. Also, the console 12 of this embodiment is an example of the control device of the present disclosure.

[0024] First, the mammography device 10 of this embodiment will be described. Fig. 2 shows a side view illustrating an example of the appearance of the mammography device 10 of this embodiment. Fig. 2 shows an example of the appearance of the mammography device 10 when viewed from the right side of the subject.

[0025] The mammography device 10 of this embodiment is a device that takes a radiographic image of a subject's breast as a subject by irradiating the breast with radiation R (e.g., X-rays). Note that the mammography device 10 may be a device that takes an image of the subject's breast not only when the subject is standing (standing position) but also when the subject is sitting in a chair (including a wheelchair) or the like (sitting position).

[0026] Furthermore, the mammography device 10 of this embodiment has the function of performing two types of imaging: so-called contrast imaging, in which imaging is performed with a contrast agent injected into the subject's breast, and general imaging. In this embodiment, imaging performed with a contrast agent injected into the subject's breast is referred to as "contrast imaging," and imaging other than contrast imaging is referred to as "general imaging."

[0027] As shown in Fig. 2, the mammography apparatus 10 of this embodiment includes a control unit 20, a memory unit 22, an I / F (Interface) unit 24, and an operation unit 26 inside an imaging stand 30. The control unit 20 controls the overall operation of the mammography apparatus 10 under the control of the console 12. The control unit 20 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), all of which are not shown. The ROM stores various programs in advance, including an imaging processing program executed by the CPU for controlling the imaging of radiographic images. The RAM temporarily stores various data.

[0028] The memory unit 22 stores image data of a radiation image captured by the radiation detector 28 and various other information. Specific examples of the memory unit 22 include a hard disk drive (HDD) and a solid state drive (SSD). The I / F unit 24 communicates various information with the console 12 by wireless communication or wired communication. Image data of a radiation image captured by the radiation detector 28 in the mammography apparatus 10 is transmitted to the console 12 via the I / F unit 24 by wireless communication or wired communication.

[0029] The operation unit 26 is provided as a plurality of switches on, for example, the imaging stand 30 of the mammography apparatus 10. The operation unit 26 may be provided as a touch panel switch, or as a foot switch that is operated by a user such as a doctor or technician with his / her foot.

[0030] The radiation detector 28 detects radiation R that has passed through the breast, which is the subject. As shown in Fig. 2, the radiation detector 28 is disposed inside the imaging stand 30. When imaging is performed in the mammography apparatus 10 of this embodiment, the breast of the subject is positioned on the imaging surface 30A of the imaging stand 30 by the user.

[0031] The radiation detector 28 detects radiation R that has passed through the subject's breast and the imaging table 30, generates a radiographic image based on the detected radiation R, and outputs image data representing the generated radiographic image. The type of radiation detector 28 in this embodiment is not particularly limited, and may be, for example, an indirect conversion type radiation detector that converts radiation R into light and then converts the converted light into an electric charge, or a direct conversion type radiation detector that directly converts radiation R into an electric charge.

[0032] The radiation irradiation unit 37 includes a radiation source 37R. As shown in Fig. 2, the radiation irradiation unit 37 is provided on the arm unit 32 together with the imaging table 30 and the compression unit 36. As shown in Fig. 2, a face guard 38 is detachably provided on the arm unit 32 at a position close to the subject and below the radiation irradiation unit 37. The face guard 38 is a protective member for protecting the subject from radiation R emitted from the radiation source 37R.

[0033] As shown in Fig. 2, the mammography apparatus 10 of this embodiment includes an arm unit 32, a base 34, and a shaft unit 35. The arm unit 32 is held by the base 34 so as to be movable in the up-down direction (Z-axis direction). The shaft unit 35 connects the arm unit 32 to the base 34. The arm unit 32 is rotatable relative to the base 34, with the shaft unit 35 serving as the axis of rotation.

[0034] The arm section 32, the imaging stand 30, and the compression unit 36 ​​are separately rotatable relative to the base 34 with the shaft section 35 as a rotation axis. In this embodiment, the base 34, the arm section 32, the imaging stand 30, and the compression unit 36 ​​are each provided with an engagement section (not shown), and by switching the state of this engagement section, each of the arm section 32, the imaging stand 30, and the compression unit 36 ​​is connected to the base 34. One or both of the arm section 32, the imaging stand 30, and the compression unit 36 ​​connected to the shaft section 35 rotate together around the shaft section 35.

[0035] The compression unit 36 ​​is provided with a compression plate drive section (not shown) that moves the compression plate 40 in the up-down direction (Z-axis direction). The compression plate 40 of this embodiment has a function of compressing the breast of the subject. A support section 46 of the compression plate 40 is detachably attached to the compression plate drive section, and is moved in the up-down direction (Z-axis direction) by the compression plate drive section to compress the breast of the subject between the compression plate 40 and the imaging table 30.

[0036] On the other hand, the console 12 in this embodiment has the function of controlling the mammography apparatus 10 using shooting orders and various information obtained from a RIS (Radiology Information System) 2, etc. via a wireless communication LAN (Local Area Network), etc., and instructions given by a user via an operation unit 56, etc.

[0037] The console 12 of this embodiment is, for example, a server computer. As shown in Fig. 3, the console 12 includes a control unit 50, a storage unit 52, an I / F unit 54, an operation unit 56, a timer 57, and a display unit 58. The control unit 50, the storage unit 52, the I / F unit 54, the operation unit 56, the timer 57, and the display unit 58 are connected to each other via a bus 59 such as a system bus or a control bus so as to be able to transmit and receive various information to and from each other.

[0038] The control unit 50 of this embodiment controls the overall operation of the console 12. The control unit 50 includes a CPU 50A, a ROM 50B, and a RAM 50C. The ROM 50B stores various programs including a contrast imaging control processing program 51A and a differential image display program 51B to be described later, which are executed by the CPU 50A. The RAM 50C temporarily stores various data. The CPU 50A of this embodiment is an example of a processor of the present disclosure. The contrast imaging control processing program 51A of this embodiment is an example of a control program of the present disclosure.

[0039] The storage unit 52 stores image data of radiographic images captured by the mammography apparatus 10, various other information, etc. Specific examples of the storage unit 52 include an HDD and an SSD.

[0040] The operation unit 56 is used by the user to input instructions regarding radiographic image capture, including instructions for irradiating radiation R, and various types of information. The operation unit 56 is not particularly limited, and examples thereof include various switches, a touch panel, a touch pen, and a mouse. The display unit 58 displays various types of information. The operation unit 56 and the display unit 58 may be integrated into a touch panel display.

[0041] The I / F unit 54 communicates various types of information between the mammography apparatus 10 and the RIS 2 via wireless or wired communication. The console 12 of this embodiment receives image data of a radiation image captured by the mammography apparatus 10 from the mammography apparatus 10 via the I / F unit 54 via wireless or wired communication.

[0042] The timer 57 starts counting when it receives a start instruction from the user via the operation unit 56, and stops counting when it receives a stop instruction from the user via the operation unit 56. In other words, the timer 57 counts the time from when it receives a start instruction from the user to when it receives a stop instruction.

[0043] Further, Fig. 4 shows a functional block diagram of an example of the configuration of the console 12 of this embodiment. As shown in Fig. 4, the console 12 includes a control unit 60, a first acquisition unit 62, a second acquisition unit 64, a generation unit 66, and an identification unit 68. As an example, in the console 12 of this embodiment, the CPU 50A of the control unit 50 executes a contrast imaging control processing program 51A stored in the ROM 50B, so that the CPU 50A functions as the control unit 60, the first acquisition unit 62, the second acquisition unit 64, the generation unit 66, and the identification unit 68.

[0044] The control unit 60 has a function of controlling the irradiation of radiation R in the mammography device 10 during contrast imaging. In this embodiment, when contrast imaging is performed, radiation R of a first energy is irradiated from the radiation source 37R to a breast in a state where a contrast agent has been injected, and a radiographic image is captured. In addition, radiation R of a second energy higher than the first energy is irradiated from the radiation source 37R to a breast in a state where a contrast agent has been injected, and a radiographic image is captured. In this embodiment, a radiographic image captured by irradiating radiation R of the first energy is referred to as a "low energy image", and a radiographic image captured by irradiating radiation R of the second energy is referred to as a "high energy image". In addition, when images captured by the mammography device 10 are collectively referred to without distinguishing between types such as low energy images and high energy images, they are simply referred to as "radiographic images".

[0045] For example, an iodine contrast agent with a k-absorption edge of 32 keV is commonly used as a contrast agent for contrast imaging. In this case, a low-energy image is captured by irradiating radiation R with a first energy lower than the k-absorption edge of the iodine contrast agent. A high-energy image is captured by irradiating radiation R with a second energy higher than the k-absorption edge of the iodine contrast agent.

[0046] Therefore, in the present embodiment, the controller 60 controls the radiation source 37R to irradiate radiation R of a first energy and radiation R of a second energy during contrast imaging. In other words, the controller 60 controls the mammography apparatus 10 to capture low-energy images and high-energy images.

[0047] Body tissues such as mammary glands and contrast agents have different radiation absorption characteristics. Therefore, the high-energy image captured as described above shows body tissues such as mammary glands and fat, as well as a clear image of the contrast agent. Meanwhile, the low-energy image shows almost no contrast agent, and shows body tissues such as mammary glands clearly. Therefore, a difference image showing the difference between the low-energy image and the high-energy image can be an image in which the mammary gland structure has been removed and the contrast agent is clearly shown.

[0048] In addition, the control unit 60 of this embodiment has the function of controlling the mammography device 10 to re-take each of the low-energy image and the high-energy image when the identification unit 68, which will be described in detail later, identifies that re-imaging is to be performed.

[0049] The first acquisition unit 62 has a function of acquiring the elapsed time since the contrast agent was injected into the breast. In this embodiment, when the contrast agent is injected into the breast, the user operates the operation unit 56 to instruct the start of counting. In response to this instruction, the timer 57 starts counting as described above. The first acquisition unit 62 acquires the time counted by the timer 57 as the elapsed time since the contrast agent was injected into the breast (hereinafter simply referred to as "elapsed time"). The first acquisition unit 62 outputs the acquired elapsed time to the generation unit 66.

[0050] The second acquisition unit 64 has a function of acquiring low-energy images and high-energy images captured by the mammography device 10. Specifically, it acquires image data representing low-energy images and high-energy images captured by the radiation detector 28 of the mammography device 10 via the I / F unit 24 and the I / F unit 54. The second acquisition unit 64 outputs the acquired low-energy images and high-energy images to the generation unit 66.

[0051] The generating unit 66 has a function of generating a difference image showing the difference between each of the low-energy image and the high-energy image. As an example, the generating unit 66 of the present embodiment generates difference image data representing a difference image in which the mammary gland tissue is removed and the contrast agent is emphasized by subtracting image data obtained by multiplying the low-energy image by a predetermined coefficient for each corresponding pixel from image data obtained by multiplying the high-energy image by a predetermined coefficient. When the high-energy image is re-imaging, the generating unit 66 also generates a difference image by the re-imaging high-energy image. The difference image in this case is an example of a re-imaging difference image of the present disclosure. The generating unit 66 outputs the generated difference image to each of the identifying unit 68 and the display control unit 69 in association with the elapsed time acquired from the first acquiring unit 62.

[0052] The determination unit 68 has the function of performing image analysis on the difference image as an analysis regarding the amount of contrast, and determining whether or not to retake low-energy and high-energy images of the breast with the contrast agent injected, based on the analysis results and the elapsed time.

[0053] The determination unit 68 performs image analysis on the contrast amount on the difference image to determine whether the contrast agent has sufficiently penetrated, particularly whether the contrast agent has sufficiently penetrated into the region of interest. As an example, in this embodiment, when the brightness value of the region of interest in the difference image is higher than the surrounding area, specifically when the contrast of the region of interest is equal to or greater than a threshold, it is considered that the contrast agent has sufficiently penetrated into the region of interest. In this embodiment, if a high-energy image is captured in a state in which the contrast agent has sufficiently penetrated into the region of interest, re-imaging is not required. Therefore, when the contrast of the region of interest in the difference image is equal to or greater than a threshold, the determination unit 68 determines that re-imaging is not to be performed. Note that the threshold for determining whether the contrast agent has sufficiently penetrated into the region of interest may be determined in advance according to the type of contrast agent, the amount of mammary glands in the breast, the type of object of interest, and the like. In addition, the threshold may be set by the user.

[0054] On the other hand, the ease of penetration of the contrast agent tends to vary depending on the type of contrast agent, the blood flow in the breast, the amount of mammary gland in the breast, the height of the subject, the weight of the subject, the type of object of interest, etc. The faster the rate at which the contrast agent penetrates, the easier it is to say that the contrast agent penetrates.

[0055] For example, even in the case of a contrast agent using iodine, the speed at which the contrast agent penetrates into the region of interest tends to differ depending on the amount of iodine contained in the contrast agent. Thus, the ease of penetration of a contrast agent tends to differ depending on the type of contrast agent. Regarding the "type of contrast agent," the type of contrast agent is said to be different when at least one of the contrast component such as iodine contained in the contrast agent and the content of the contrast component in the contrast agent is different.

[0056] In addition, for example, since the contrast agent flows through the blood vessels while mixing with the blood, the faster the blood flow, the faster the penetration speed of the contrast agent tends to be. Thus, the ease of penetration of the contrast agent tends to differ depending on the blood flow in the breast. Note that the blood flow of the subject may be applied instead of the blood flow of the breast itself.

[0057] Also, for example, the greater the amount of mammary glands in the breast, the easier the contrast agent tends to penetrate. Therefore, the denser the breast, the easier the contrast agent tends to penetrate. On the other hand, the greater the amount of mammary glands, the higher the probability that the mammary glands will be hidden by background mammary glands, so it may be preferable to perform imaging early regardless of whether the contrast agent has penetrated sufficiently. Also, for example, the more obese the subject, the harder the contrast agent tends to penetrate.

[0058] In addition, for example, lesions such as tumors are more easily permeated by contrast agents than breast tissue, and the more malignant the lesion is, the faster the contrast agent penetrates and the faster the contrast agent washes out, but some cancers such as mucinous carcinoma tend to have a relatively slow rate of penetration of the contrast agent. Therefore, the ease of penetration of the contrast agent tends to differ depending on the type of region of interest and whether the lesion is malignant or not.

[0059] When the contrast of the region of interest in the difference image is less than the threshold, the contrast agent may not have penetrated sufficiently, the penetrated contrast agent may have started to wash out, or the amount of penetration of the contrast agent may be small due to some circumstances. In this embodiment, the specifying unit 68 specifies that the high energy image is to be re-captured when the contrast of the region of interest in the difference image is less than the threshold and the elapsed time is less than the threshold. That is, the specifying unit 68 specifies that the high energy image is to be re-captured when the contrast of the region of interest in the difference image is less than the threshold and the elapsed time is equal to or greater than the threshold. That is, the specifying unit 68 specifies that the high energy image is not to be re-captured when the contrast of the region of interest in the difference image is less than the threshold and the elapsed time is equal to or greater than the threshold. That is, the specifying unit 68 specifies that the high energy image is not to be re-captured when the contrast agent that has penetrated into the region of interest has started to wash out, or when the amount of penetration of the contrast agent is small due to some circumstances.

[0060] As mentioned above, the penetration speed of the contrast agent varies depending on the type of contrast agent, blood flow in the breast, mammary gland volume in the breast, the subject's height, the subject's weight (weight of the subject), and the type of object of interest, etc., so it is preferable that the threshold time be determined depending on at least one of these.

[0061] Furthermore, when re-imaging a high-energy image, the determination unit 68 derives the timing to re-imaging. As an example, in this embodiment, the timing to re-imaging a high-energy image is determined to be the timing when the elapsed time reaches a threshold time. Therefore, the determination unit 68 derives the timing to re-imaging a high-energy image based on the threshold time and the elapsed time. When re-imaging a high-energy image, the determination unit 68 outputs information indicating the timing to re-imaging to the control unit 60.

[0062] Moreover, the console 12 of the present embodiment includes a display control unit 69. As an example, in the console 12 of the present embodiment, the CPU 50A of the control unit 50 executes a differential image display program 51B stored in the ROM 50B, so that the CPU 50A functions as the display control unit 69.

[0063] The display control unit 69 has a function of displaying the difference image generated by the generation unit 66 on the display unit 58. The display control unit 69 of this embodiment derives contrast amount information related to the contrast amount from the difference image. Examples of contrast amount information include a numerical value representing the contrast amount. For example, in the case of a numerical value representing the contrast amount of the region of interest, the display control unit 69 first identifies the region of interest from the difference image. Note that the method by which the display control unit 69 identifies the region of interest from the difference image is not particularly limited. For example, the region of interest may be identified from the difference image by accepting information regarding the region of interest input by the user. Specifically, at least one image of the difference image, the low energy image, and the high energy image may be displayed on the display unit 58, and a region designated by the user by operating the operation unit 56 on the displayed image may be accepted as information regarding the region of interest. For example, the display control unit 69 may identify the region of interest by applying CAD (Computer Aided Diagnosis) to the difference image.

[0064] The pixel value of the pixel in the difference image corresponds to the amount of contrast. Therefore, the amount of contrast can be derived from the pixel value of the difference image. The display control unit 69 derives the amount of contrast based on the pixel value of the pixel of the image corresponding to the specified region of interest. The display control unit 69 may derive any of the total, average, median, and maximum values ​​of the amount of contrast in the entire region of interest, and which one is to be derived may be determined in advance or may be designated by the user. The display control unit 69 may also derive a numerical value representing the amount of contrast regardless of the region of interest. For example, the display control unit 69 may derive a numerical value representing the amount of contrast in a position or region designated by the user for the difference image or the like. For example, the display control unit 69 may also derive a numerical value representing the amount of contrast in a region outside the specified region of interest.

[0065] Next, the operation of the console 12 in contrast imaging using the radiation image capturing system 1 of this embodiment will be described with reference to the drawings. FIG. 5 shows a flow chart showing an example of the flow of contrast imaging by the radiation image capturing system 1 of this embodiment. FIG. 6A shows an example of a time chart of contrast imaging when re-imaging is performed. FIG. 6B shows an example of a time chart of contrast imaging when re-imaging is not performed. In this embodiment, when the first captured low-energy image 70L0 and the re-imaging low-energy image 70L1 are collectively referred to without distinction, they may be called low-energy image 70L. Similarly, in this embodiment, when the first captured high-energy image 70H0 and the re-imaging high-energy image 70H1 are collectively referred to without distinction, they may be called high-energy image 70H. In this embodiment, when the difference image 720 showing the difference between the first captured low-energy image 70L0 and the high-energy image 70H0 and the difference image 721 showing the difference between the re-imaging low-energy image 70L1 and the high-energy image 70H1 are collectively referred to without distinction, they may be called difference image 72.

[0066] When performing contrast imaging, first, the user injects a contrast agent into the breast to be photographed, as shown in step S10 of Fig. 5. Then, as shown in the next step S12, the user operates operation unit 56 to start counting by timer 57. Next, as shown in step S14, the user positions the breast of the subject on imaging table 30 of mammography device 10 and compresses the breast with compression plate 40.

[0067] Next, in step S16, the contrast imaging control process shown in Fig. 7 for capturing a low-energy image 70L and a high-energy image 70H by the mammography apparatus 10 is performed by the console 12. As an example, the CPU 50A of the control unit 50 executes the contrast imaging control process program 51A stored in the ROM 50B in the console 12 of this embodiment to perform the contrast imaging control process shown in Fig. 7. Fig. 7 shows a flowchart illustrating an example of the flow of the contrast imaging control process executed by the console 12 of this embodiment.

[0068] 7, the control unit 60 determines whether or not it has received an instruction to irradiate radiation R. Until an irradiation instruction is received, the determination in step S100 remains negative. On the other hand, if an irradiation instruction is received, the determination in step S100 remains positive, and the process proceeds to step S102.

[0069] In step S102, the control unit 60 outputs an instruction to the mammography apparatus 10 to irradiate the first energy radiation R. In the mammography apparatus 10, based on an instruction input from the console 12, the control unit 20 causes the radiation source 37R to irradiate the breast with the first energy radiation R, and the radiation detector 28 captures a low-energy image 70L.

[0070] In step S104, the control unit 60 outputs an instruction to the mammography apparatus 10 to irradiate the second energy radiation R, and then proceeds to step S106. In the mammography apparatus 10, the control unit 20 causes the radiation source 37R to irradiate the breast with the second energy radiation R based on an instruction input from the console 12, and the radiation detector 28 captures a high-energy image 70H.

[0071] The order of capturing the low-energy image 70L and the high-energy image 70H is not limited to that of the present embodiment, and the high-energy image 70H may be captured before the low-energy image 70L. That is, the order of the process of step S102 and the process of step S104 may be reversed.

[0072] In the next step S106, the first acquisition unit 62 acquires the elapsed time as described above, and the second acquisition unit 64 acquires the low-energy image 70L and the high-energy image 70H as described above.

[0073] In the next step S108, the generator 66 generates a difference image 72 from the low-energy image 70L and the high-energy image 70H acquired in step S106, as described above. In the example shown in Figures 6A and 6B, the generator 66 generates a difference image 720 showing the difference between the low-energy image 70L0 and the high-energy image 70H0.

[0074] In the next step S110, the identification unit 68 identifies the region of interest in the difference image 72. As an example, the identification unit 68 of this embodiment identifies the region of interest by applying CAD to the difference image 72 generated in step S108.

[0075] In the next step S112, the determination unit 68 acquires prior information. The prior information is information for identifying the threshold time, and is information obtained before the current contrast imaging. As described above, as an example, the threshold time in this embodiment is determined according to at least one of the type of contrast agent, the blood flow of the breast, the mammary gland volume of the breast, the height of the subject, the weight of the subject, and the type of the object of interest. The method by which the determination unit 68 acquires the prior information is not particularly limited.

[0076] For example, when there is an image previously captured of the breast currently undergoing contrast imaging, the identification unit 68 may acquire prior information from the image previously captured. Examples of images previously captured include a radiographic image, an ultrasound image, a CT (Computed Tomography) image, and an MRI (Magnetic Resonance Imaging) image of the breast currently undergoing contrast imaging. The identification unit 68 applies CAD to at least one of these images to acquire the amount of mammary glands in the breast, the presence or absence of a region of interest, the degree of malignancy of a lesion, and the like as the type of object of interest. Alternatively, when a doctor or the like has attached an interpretation result to these images, the identification unit 68 acquires the interpretation result as prior information.

[0077] For example, the specifying unit 68 may obtain advance information such as the type of contrast agent, the blood flow of the breast, the height and weight of the subject, and the type of object of interest from an imaging menu, an imaging order, an electronic medical record, etc. For example, the specifying unit 68 may obtain advance information input by the user using the operation unit 56.

[0078] In addition, since the identification unit 68 may acquire multiple types of prior information, the priorities of the multiple types of prior information may be set in advance, or the priorities may be set by the user. For example, the identification unit 68 may adopt the most recent prior information at the current time. Also, for example, when a malignant lesion is identified as an object of interest, the identification unit 68 may adopt the prior information regarding the identified malignant lesion, regardless of the time when the prior information in which the malignant lesion is identified is dated.

[0079] When there is no prior information that the specifying unit 68 can acquire, the specifying unit 68 specifies that the prior information cannot be acquired.

[0080] In the next step S114, the specifying unit 68 performs, as described above, image analysis relating to the contrast amount on the difference image 72. In this embodiment, as described above, the contrast of the region of interest in the difference image 72 is derived as the analysis result.

[0081] In the next step S116, the determination unit 68 determines whether or not the contrast derived in the above step S114 is equal to or greater than a threshold (contrast≧threshold), as described above. If the contrast is not equal to or greater than the threshold, in other words, if the contrast is less than the threshold, the determination in step S116 is negative, and the process proceeds to step S118.

[0082] In step S118, the determination unit 68 determines whether the elapsed time is equal to or greater than the threshold time (elapsed time≧threshold time) as described above. The threshold time used in this process is determined according to the prior information acquired in step S112. In the present embodiment, as an example, correspondence information indicating the correspondence between the prior information and the threshold time is stored in advance in the storage unit 52. The determination unit 68 determines the threshold time corresponding to the prior information acquired in step S112 by referring to the correspondence information stored in the storage unit 52. If the elapsed time is not equal to or greater than the threshold time, in other words, if the elapsed time is less than the threshold time, as described above, it can be considered that the contrast agent has not yet sufficiently penetrated. Therefore, the determination in step S118 is negative, and the determination unit 68 determines that the high energy image 70H is to be re-imaging, returns to step S102, and repeats the processes in steps S102 to S116. As a result, re-imaging is performed, for example, as shown in FIG. 6A.

[0083] On the other hand, if the elapsed time is equal to or greater than the threshold time, as described above, the contrast agent has begun to wash out or the amount of penetration of the contrast agent is low for some reason, so the determination unit 68 determines that the high-energy image 70H will not be re-captured, and terminates the contrast imaging control process shown in Figure 7.

[0084] Moreover, if the contrast is equal to or greater than the threshold in step S116, it can be considered that the contrast agent has sufficiently penetrated, as described above. Therefore, the determination in step S116 is positive, and the contrast imaging control process shown in FIG. 7 is terminated.

[0085] When the contrast imaging control process shown in Fig. 7 ends in this manner, the process of step S16 shown in Fig. 5 ends. When the process of step S16 ends, the contrast imaging ends. The control unit 60 may notify the user that the contrast imaging has ended.

[0086] Therefore, in the next step S18, compression of the breast is released. Specifically, the control unit 60 outputs an instruction to the mammography device 10 to move the compression plate 40 in a direction away from the imaging table 30. Based on the input instruction, the control unit 50 of the mammography device 10 moves the compression plate 40 in a direction away from the imaging table 30. This releases compression of the breast. Note that breast compression may be released in response to an instruction from the user, or automatically in response to the end of contrast imaging.

[0087] In the next step S20, the console 12 performs the differential image display process shown in Fig. 8. As an example, the CPU 50A of the control unit 50 executes the differential image display program 51B stored in the ROM 50B in the console 12 of this embodiment to perform the differential image display process shown in Fig. 8. Fig. 8 shows a flowchart showing an example of the flow of the differential image display process executed in the console 12 of this embodiment.

[0088] In step S200, the display control unit 69 derives contrast amount information as described above. Specifically, the display control unit 69 derives contrast amount information from the difference image 72 generated in step S108 of the contrast imaging control process shown in Fig. 7 and executed in step S16 above.

[0089] In the next step S202, the display control unit 69 performs image processing to enhance the difference image 72. Examples of image processing performed by the display control unit 69 include gradation enhancement processing and frequency enhancement processing. The display control unit 69 of this embodiment performs an analysis such as a histogram analysis on the difference image 72 generated by the generation unit 66, and specifies whether the image processing, gradation enhancement processing or frequency enhancement processing, is to be performed, and the degree of enhancement. The display control unit 69 performs image processing on the difference image 72 according to the specified image processing and degree of enhancement, and generates a difference image 82 after image processing (hereinafter simply referred to as "difference image 82").

[0090] In order to easily compare the difference image 720 and the difference image 721, it is preferable that the image processing performed by the display control unit 69 on the difference image 720 is the same as the image processing performed on the difference image 721. It is also preferable that the degree of emphasis in the image processing performed by the display control unit 69 on the difference image 720 is the same as the degree of emphasis in the image processing performed on the difference image 721.

[0091] In the next step S204, the display control unit 69 controls the display unit 58 to display the contrast amount information derived in the above step S200 and the difference image 82 after the image processing in the above step S202. When the process of step S204 ends, the difference image generation process shown in FIG. 8 ends.

[0092] 9 shows an example of a state in which a difference image 82 and contrast amount information 80 are displayed on the display unit 58. As shown in FIG. 9, the display control unit 69 of this embodiment causes the display unit 58 to display a difference image 820 obtained by image processing of the difference image 720 and a difference image 821 obtained by image processing of the difference image 721 obtained by re-imaging side by side. In addition, in the example shown in FIG. 9, the display control unit 69 causes the difference image 820 to be displayed with contrast amount information 800 of the region of interest and elapsed time information 830 indicating the elapsed time corresponding to the difference image 820 superimposed thereon. In addition, the display control unit 69 causes the difference image 821 to be displayed with contrast amount information 801 of the region of interest and elapsed time information 831 indicating the elapsed time corresponding to the difference image 821 superimposed thereon.

[0093] 9, when a radiation image 84 captured by general radiography of the subject breast, in other words a radiation image 84 captured without injection of a contrast agent, exists, the display control unit 69 also causes the display unit 58 to display the radiation image 84 as a comparative example. As described above, since the low-energy image shows almost no contrast agent and clearly shows body tissues such as mammary glands, a low-energy image 70L may be displayed on the display unit 58 instead of the radiation image 84.

[0094] In addition, in the example shown in FIG. 9, the differential image 820 and the differential image 821 are displayed side by side, but it is also possible to display either the differential image 820 or the differential image 821, and switch the differential image to be displayed in response to a user instruction.

[0095] When the difference image display process shown in Fig. 8 is thus completed, the difference image display process of step S20 shown in Fig. 5 is completed. This completes a series of processes related to contrast imaging in the radiation image capturing system 1 of this embodiment. The low-energy image 70L and the multiple high-energy images 70H captured by the mammography apparatus 10 of this embodiment, the elapsed time information 83, the multiple difference images 72 generated by the console 12, the difference image 82 after image processing, and the contrast amount information 80 may be stored in the memory unit 52 of the console 12, a PACS (Picture Archiving and Communication Systems), etc.

[0096] In the above embodiment, the difference image display process is performed continuously after the process of S18 in Fig. 5 is completed, but the timing of the difference image display process, i.e., the timing of displaying the difference image 82, is not limited to this embodiment. For example, the difference image 82 may be displayed at a timing according to the user's desire after contrast imaging.

[0097] As described above, the console 12 of the above embodiment includes the CPU 50A as at least one processor. The CPU 50A acquires the elapsed time since the contrast agent was injected into the breast whose radiation image is to be captured by the mammography device 10. The CPU 50A also acquires a low-energy image captured by the mammography device 10 by irradiating the breast with the contrast agent injected with radiation R of a first energy, and a high-energy image captured by the mammography device 10 by irradiating the breast with the contrast agent injected with radiation R of a second energy higher than the first energy. The CPU 50A also generates a difference image showing the difference between the low-energy image and the high-energy image. The CPU 50A also specifies whether or not to re-capture a high-energy image of the breast with the contrast agent injected based on the result of the analysis of the contrast amount performed on the difference image and the elapsed time.

[0098] The degree of penetration of the contrast agent into the breast varies depending on various conditions such as the amount of mammary glands in the breast and the type of object of interest. Therefore, it may be difficult to determine the timing of imaging. Also, even if the captured difference image is referred to, it may be difficult to determine whether the contrast agent can be considered to have sufficiently penetrated. In such a case, in this embodiment, it is determined whether or not to re-capture a high-energy image based on the analysis result of the contrast amount performed on the difference image showing the difference between the low-energy image and the high-energy image and the elapsed time. Therefore, according to this embodiment, it is possible to capture a high-energy image at an appropriate timing in contrast imaging.

[0099] Furthermore, according to this embodiment, the number of times re-imaging can be set to an appropriate number, so that the amount of radiation exposure to the subject can be reduced.

[0100] In the above embodiment, the re-imaging has been described as a form in which both low-energy images and high-energy images are re-imaging, but the present invention is not limited to this embodiment, and any form may be used as long as at least high-energy images are re-imaging. That is, low-energy images do not need to be re-imaging. As described above, low-energy images clearly show the mammary gland structure, but hardly show the contrast agent. Therefore, low-energy images tend to be similar images regardless of the penetration of the contrast agent over time. Therefore, low-energy images may not need to be re-imaging more frequently than high-energy images.

[0101] Fig. 10 shows an example of a time chart for re-imaging only the high-energy image. In the example shown in Fig. 10, after compression of the breast, first, a low-energy image 70L0 and a high-energy image 70H0 are captured, and the generating unit 66 generates a difference image 720. When the identifying unit 68 identifies that re-imaging is to be performed based on the image analysis result of the difference image 72, the control unit 60 re-imaging only the high-energy image 70H1. Then, the generating unit 66 generates a difference image 721 between the low-energy image 70L0 and the high-energy image 70H1.

[0102] In this way, by retaking only the high-energy image, the number of times low-energy images are taken can be reduced, thereby reducing the radiation exposure of the subject. On the other hand, since body movement of the breast may occur due to movement of the mammary gland structure, it is preferable to retake the low-energy image when body movement is taken into consideration.

[0103] In the above embodiment, re-imaging is performed until a positive determination is made in step S116 of the contrast imaging control process (see FIG. 7) or until a positive determination is made in step S118. That is, re-imaging is performed multiple times until the above condition is satisfied. However, the number of times re-imaging is performed is not limited, and for example, an upper limit may be set, or re-imaging may be performed only once.

[0104] In the above embodiment, the high energy image and the low energy image are automatically re-photographed, but the re-photographing may be performed according to a user's instruction. For example, when the determination unit 68 determines to perform re-photographing, the control unit 60 may notify the user of the timing of re-photographing, and may perform re-photographing by accepting the instruction of the user in response to the notification.

[0105] In the present embodiment, the console 12 includes the timer 57, and the console 12 itself counts the elapsed time. However, the console 12 may not include the timer 57, and an external device may count the elapsed time. For example, the console 12 may measure the elapsed time using a measuring device such as a stopwatch and input the measured time into the console 12 using the operation unit 56, and the first acquisition unit 62 may acquire the input elapsed time.

[0106] In the above embodiment, the threshold time and the timing of re-imaging are specified based on prior information, but the timing of first capturing a low-energy image and a high-energy image after the injection of a contrast agent may also be derived based on prior information. In this case, the timing of first capturing a low-energy image and a high-energy image is different from the threshold time and the timing of re-imaging.

[0107] In the above embodiment, a breast is applied as an example of a subject of the present disclosure, and a mammography device 10 is applied as an example of a radiation image capturing device of the present disclosure, but the subject is not limited to a breast, and the radiation image capturing device is not limited to a mammography device. For example, the subject may be a chest or abdomen, and the radiation image capturing device may be a radiation image capturing device other than a mammography device.

[0108] In the above embodiment, the console 12 is an example of the control device of the present disclosure, but the functions of the control device of the present disclosure may be provided in a device other than the console 12. In other words, some or all of the functions of the control unit 60, the first acquisition unit 62, the second acquisition unit 64, the generation unit 66, the identification unit 68, and the display control unit 69 may be provided in a device other than the console 12, such as the mammography device 10 or an external device.

[0109] In the above embodiment, the following various processors can be used as the hardware structure of the processing units that execute various processes, such as the control unit 60, the first acquisition unit 62, the second acquisition unit 64, the generation unit 66, the identification unit 68, and the display control unit 69. As described above, the above various processors include a CPU, which is a general-purpose processor that executes software (programs) and functions as various processing units, as well as a programmable logic device (PLD), which is a processor whose circuit configuration can be changed after manufacture, such as an FPGA (Field Programmable Gate Array), a dedicated electric circuit, which is a processor having a circuit configuration designed specifically for executing specific processes, such as an ASIC (Application Specific Integrated Circuit), etc.

[0110] A single processing unit may be configured with one of these various processors, or may be configured with a combination of two or more processors of the same or different types (for example, a combination of multiple FPGAs, or a combination of a CPU and an FPGA). Also, multiple processing units may be configured with a single processor.

[0111] As an example of configuring multiple processing units with one processor, first, there is a form in which one processor is configured with a combination of one or more CPUs and software, and this processor functions as multiple processing units, as represented by computers such as client and server. Second, there is a form in which a processor is used to realize the functions of the entire system including multiple processing units with one IC (Integrated Circuit) chip, as represented by a system on chip (SoC). In this way, the various processing units are configured using one or more of the above various processors as a hardware structure.

[0112] Furthermore, more specifically, the hardware structure of these various processors can be an electric circuit that combines circuit elements such as semiconductor elements.

[0113] In the above-mentioned embodiments, the contrast imaging control processing program 51A and the differential image display program 51B are stored (installed) in advance in the ROM 50B, but the present invention is not limited to this. Each of the contrast imaging control processing program 51A and the differential image display program 51B may be provided in a form recorded on a recording medium such as a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), or a USB (Universal Serial Bus) memory. Each of the contrast imaging control processing program 51A and the differential image display program 51B may be downloaded from an external device via a network.

[0114] The disclosure of Japanese Patent Application No. 2020-162697, filed on September 28, 2020, is incorporated herein by reference in its entirety.

[0115] All publications, patent applications, and standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or standard was specifically and individually indicated to be incorporated by reference. [Explanation of symbols]

[0116] 1 Radiography system 2.RIS 10 Mammography equipment 12 Console 20, 50 Control unit 22, 52 storage section 24, 54 I / F section 26, 56 Operation section 28 Radiation Detector 30 Shooting table, 30A Shooting surface 32 Arm section 34 Foundation 35 Shaft 36 Compression Unit 37 Radiation irradiation section, 37R radiation source 38 Face Guard 40 Compression Plate 46 Support part 50A CPU, 50B ROM, 50C RAM 51A contrast imaging control processing program, 51B difference image display program 57 Timer 58 Display section 59 Bus 60 Control section 62 First acquisition part 64 Second acquisition part 66 Generation part 68 Specific part 69 Display control section 70L0, 70L1 low energy images 70H0, 70H1 high energy images 720, 721, 820, 821 difference images 800, 801 contrast amount information 830, 831 Elapsed time information 84 Radiological Images R Radiation

Claims

1. At least one processor; The processor, The time elapsed since the contrast agent was injected into the subject whose radiation image is to be captured by the radiation image capturing device is acquired; a low-energy image captured by a radiographic imaging device by irradiating a subject having the contrast agent injected therein with radiation of a first energy, and a high-energy image captured by the radiographic imaging device by irradiating a subject having the contrast agent injected therein with radiation of a second energy higher than the first energy, generating a difference image indicative of the difference between the low-energy image and the high-energy image; Based on the result of the analysis of the contrast amount performed on the difference image and the elapsed time, it is determined whether or not to re-take the high-energy image of the subject in a state in which the contrast agent has been injected. Control device.

2. The processor, When it is determined that the re-photographing is to be performed, Deriving the timing to perform the re-imaging based on the analysis result and the elapsed time. The control device according to claim 1 .

3. The processor, Control is performed to cause the radiographic imaging device to re-capture the high energy image at the derived timing for re-capturing. The control device according to claim 2.

4. The processor, If the contrast of the region of interest in the difference image is equal to or greater than a predetermined threshold, it is determined that the re-imaging is not to be performed regardless of the elapsed time. The control device according to any one of claims 1 to 3.

5. The processor, When the contrast of the region of interest in the difference image is less than a predetermined threshold and the elapsed time is equal to or greater than a threshold time, it is determined that the re-imaging is not to be performed. The control device according to any one of claims 1 to 4.

6. The processor, When the contrast of the region of interest in the difference image is less than a predetermined threshold and the elapsed time is less than a threshold time, it is determined that the re-imaging is to be performed. The control device according to any one of claims 1 to 4.

7. The threshold time is a time that depends on at least one of the type of the contrast agent, the blood flow of the subject, the height of the subject, the weight of the subject, and the type of the object of interest. The control device according to claim 5 or 6.

8. the subject is a breast, The threshold time is a time that depends on the amount of milk gland in the breast. The control device according to claim 5 or 6.

9. The processor, When it is determined that the re-photographing is to be performed, Obtaining a high-energy image recaptured from the radiation image; generating a recaptured difference image showing the difference between the low-energy image and the recaptured high-energy image; The control device according to any one of claims 1 to 8.

10. The processor, When it is determined that the re-imaging is to be performed, it is determined that the re-imaging of the low-energy image is also to be performed; generating a recaptured difference image showing the difference between the recaptured low-energy image and the recaptured high-energy image; The control device according to any one of claims 1 to 8.

11. The processor, performing the same image processing on the difference image and the re-captured difference image to enhance a region of interest; The difference image that has been subjected to image processing and the re-captured difference image are displayed. The control device according to claim 9 or 10.

12. The processor, Further displaying contrast amount information regarding the contrast amount of the same region in each of the difference image and the re-captured difference image. A control device according to any one of claims 9 to 11.

13. the subject is a breast, The radiation image capturing apparatus is a mammography apparatus. A control device according to any one of claims 1 to 12.

14. 1. A method of operating a control device comprising at least one processor, comprising: The processor, The time elapsed since the contrast agent was injected into the subject whose radiation image is to be captured by the radiation image capturing device is acquired; a low-energy image captured by the radiation image capturing device by irradiating the subject into which the contrast agent has been injected with radiation of a first energy, and a high-energy image captured by the radiation image capturing device by irradiating the subject into which the contrast agent has been injected with radiation of a second energy higher than the first energy, generating a difference image indicative of the difference between the low-energy image and the high-energy image; Based on the result of the analysis of the contrast amount performed on the difference image and the elapsed time, it is determined whether or not to re-take the high-energy image of the subject in a state in which the contrast agent has been injected. How it works.

15. The time elapsed since the contrast agent was injected into the subject whose radiation image is to be captured by the radiation image capturing device is acquired; a low-energy image captured by a radiographic imaging device by irradiating a subject having the contrast agent injected therein with radiation of a first energy, and a high-energy image captured by the radiographic imaging device by irradiating a subject having the contrast agent injected therein with radiation of a second energy higher than the first energy, generating a difference image indicative of the difference between the low-energy image and the high-energy image; Based on the result of the analysis of the contrast amount performed on the difference image and the elapsed time, it is determined whether or not to re-take the high-energy image of the subject in a state in which the contrast agent has been injected. A control program that causes a computer to execute processing.

Images