X-ray device

Abstract

To provide an X-ray apparatus capable of executing fluoroscopy or radiography on an appropriate condition more reliably and quickly.SOLUTION: An X-ray apparatus includes: an X-ray tube 5 for radiating an X-ray; an X-ray detector 7 for detecting an X-ray; an image processing unit 19 for generating an X-ray image by executing image processing using a detection signal output by the X-ray detector 7; a condition storage unit 29 for storing an image acquisition condition 43 corresponding to site information 41 on a subject M in association with the site information 41; a console 27 capable of inputting an instruction for selecting a site for irradiating the subject with an X-ray as site information 41; a condition read-out unit 35 for reading out the image acquisition condition 43 associated with the site information 41 by the selection of the site information 41; a reference image generation unit 37 for generating a reference image by subjecting the X-ray image generated the latest to image processing on the basis of the image acquisition condition 43 that has been read out; and a reference image display unit 39 for displaying the reference image Fs.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an X-ray apparatus that irradiates an object with X-rays to perform X-ray fluoroscopy or X-ray photography. [Background technology]

[0002] In medical settings, when an X-ray device is used to obtain X-ray images of a subject by performing X-ray fluoroscopy or X-ray photography, it is important to set appropriate X-ray irradiation conditions or image processing conditions depending on the part of the subject to be imaged or the type of examination to be performed on the subject. In recent years, X-ray devices equipped with an anatomical program (APR) have been used as a configuration for setting appropriate X-ray irradiation conditions or image processing conditions.

[0003] An anatomical program is a data structure in which a series of X-ray irradiation conditions, such as tube voltage and tube current, and a series of image processing conditions, such as contrast processing conditions, are pre-associated with the subject's imaging region or the type of examination. Multiple anatomical programs are pre-set and stored according to the subject's imaging region or the type of examination. For example, in the case of general X-ray imaging in which the subject's imaging region is the chest, information on X-ray irradiation conditions and image processing conditions suitable for general X-ray imaging of the chest is stored in association with the general X-ray imaging in which the chest is the imaging region.

[0004] When performing X-ray fluoroscopy on a subject, multiple anatomical programs are displayed on a display unit, such as a liquid crystal panel, and the operator selects an appropriate one from the multiple anatomical programs (see, for example, Patent Documents 1 and 2).

[0005] As an example, when performing an endoscopic retrograde cholangiopancreatography (ERCP) on a subject's abdomen, the operator selects the "Abdomen / ERCP" program from multiple anatomical programs listed on the display, such as "Chest / General X-ray," "Abdomen / General X-ray," and "Abdomen / ERCP," which correspond to the examination site and type of examination. By performing this selection, the X-ray irradiation conditions and image processing condition parameters appropriate for performing ERCP on the abdomen, which have been linked to "Abdomen / ERCP" in advance, are read and displayed on the display. The operator confirms the displayed X-ray irradiation conditions, etc., and begins the examination on the subject. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-143443 [Patent Document 2] Japanese Patent Application Publication No. 2018-191983 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the conventional example having such a configuration has the following problems.

[0008] In conventional configurations, after an operator selects an appropriate program, the information displayed on the display unit is the parameters of the X-ray irradiation conditions and image processing conditions, i.e., numerical information. Therefore, simply checking the parameters, which are numerical information, makes it difficult for the operator to accurately imagine in advance the X-ray image that will be generated using the X-ray irradiation conditions and image processing conditions of those parameters. Therefore, particularly for operators with little experience, there is a concern that X-ray irradiation conditions and image processing conditions that are actually inappropriate parameters will be selected, resulting in the generation of X-ray images that are inappropriate for the examination. As a result, X-ray irradiation will have to be performed again, resulting in unnecessary exposure and prolonged examination times.

[0009] The present invention has been made in view of the above circumstances, and has as its object to provide an X-ray apparatus that can perform X-ray fluoroscopy or X-ray photography more reliably, quickly and under appropriate conditions. [Means for solving the problem]

[0010] In order to achieve the above object, the present invention has the following configuration. That is, the X-ray apparatus according to the first aspect of the present invention comprises an X-ray tube that irradiates an object with X-rays, an X-ray detector that is disposed opposite the X-ray tube and detects X-rays that have passed through the object, an image processing unit that generates an X-ray image by performing image processing using a detection signal output by the X-ray detector, and an image processing unit that stores image acquisition conditions including at least one of X-ray irradiation conditions and image processing conditions corresponding to each of a plurality of parts of the object, in association with part information that identifies any one of the parts. a storage unit that stores the X-ray image generated based on the image acquisition conditions linked to the first part information; an input unit capable of inputting an instruction to select a region of the subject to be irradiated with X-rays from a plurality of regions of the subject as region information; and the storage unit a condition reading unit that reads out the image acquisition conditions stored in the image acquisition unit; In addition, the first part information is linked to the second part information that is different from the first part information. Based on the image acquisition conditions, generated based on the image acquisition conditions linked to the first part information stored in the storage unit a reference image generating unit that performs image processing on the X-ray image to generate a reference image; and a reference image display unit that displays the reference image generated by the reference image generation unit.

[0011] An X-ray apparatus according to a second aspect of the present invention includes an X-ray tube that irradiates an object with X-rays, an X-ray detector that is disposed opposite the X-ray tube and detects X-rays that have passed through the object, an image processing unit that generates an X-ray image by performing image processing using a detection signal output by the X-ray detector, and an X-ray acquisition unit that stores image acquisition conditions that include at least one of X-ray irradiation conditions and image processing conditions corresponding to each of a plurality of examination items on the object, in association with the examination items. a storage unit that stores the X-ray image generated based on the image acquisition conditions associated with the first examination item.an input unit capable of inputting an instruction to select a type of test to be performed on the subject as a test item; and the storage unit a condition reading unit that reads out the image acquisition conditions stored in the image acquisition unit; In addition, the first test item is linked to a second test item that is different from the first test item. Based on the image acquisition conditions, generated based on the image acquisition conditions associated with the first inspection item stored in the storage unit The imaging system includes a reference image generating unit that performs image processing on the X-ray image to generate a reference image, and a reference image display unit that displays the reference image generated by the reference image generating unit. [Effects of the Invention]

[0012] According to the X-ray device of the first aspect of the present invention, by selecting a region of the subject to be irradiated with X-rays as region information, image acquisition conditions associated with the region information are read, and a reference image is generated and displayed on the reference image display unit. The reference image is obtained by applying the read image acquisition conditions to the most recently generated X-ray image and performing image processing. Therefore, by visually checking the reference image, the operator can roughly grasp in advance how the generated X-ray image will look when the image acquisition conditions corresponding to the region information selected on the input unit are applied. In other words, by visually checking the reference image, the operator can predict the level of various conditions, such as brightness and contrast, of the X-ray image. This more reliably avoids a situation in which image acquisition conditions that are actually inappropriate parameters are executed and the operator has to redo the image acquisition conditions. Therefore, appropriate image acquisition conditions can be set more reliably and quickly to perform X-ray fluoroscopy or X-ray imaging.

[0013] According to the X-ray device of the second aspect of the present invention, by selecting the type of examination to be performed on the subject as an examination item, image acquisition conditions associated with the examination item are read, and a reference image is generated and displayed on the reference image display unit. The reference image is obtained by applying the read image acquisition conditions to the most recently generated X-ray image and performing image processing. Therefore, by visually checking the reference image, the operator can predict how the generated X-ray image will look when image acquisition conditions corresponding to the target region selected on the input unit are applied. In other words, by visually checking the reference image, the operator can predict the level of various conditions such as brightness and contrast of the X-ray image, thereby more reliably avoiding a situation in which image acquisition conditions that are actually inappropriate parameters are executed and the operator has to redo the image acquisition conditions. Therefore, appropriate image acquisition conditions can be set more reliably and quickly to perform X-ray fluoroscopy or X-ray imaging. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a front view illustrating the overall configuration of an X-ray device according to a first embodiment. [Figure 2] 1 is a right side view illustrating the overall configuration of an X-ray device according to a first embodiment. [Figure 3] 1 is a functional block diagram illustrating an outline of an X-ray device according to a first embodiment. [Figure 4] 1 is a diagram illustrating an APR in Example 1. (a) is a diagram showing the relationship between body part information and image acquisition conditions linked to the body part information, and (b) is a diagram showing body part information relating to each body part and examples of specific parameters of the image acquisition conditions linked to the body part information. [Figure 5] 1A and 1B are diagrams illustrating various tables used in Example 1. (a) is a diagram showing an example of a standard body thickness table T1, (b) is a diagram showing an example of a body thickness correction value table T2, (c) is a diagram showing a plurality of average brightness tables T3 stored in a table storage unit, and (d) is a diagram showing an example of an average brightness table T3b among the average brightness tables T3. [Figure 6]1 is a flowchart illustrating a series of steps in the operation of the X-ray apparatus according to Example 1. (a) is a flowchart illustrating an outline of the operation, and (b) is a flowchart illustrating the details of step S5. [Figure 7] FIG. 10 is a diagram showing an APR selection screen in step S1 of the first embodiment. [Figure 8] FIG. 10 is a diagram illustrating step S2 in the first embodiment. [Figure 9] FIG. 10 is a diagram illustrating step S5 in the first embodiment. [Figure 10] FIG. 10 is a diagram illustrating a reference image display unit according to step S5 of the first embodiment. [Figure 11] FIG. 10 is a diagram illustrating a display unit related to step S7 of the first embodiment. [Figure 12] FIG. 2 is a diagram illustrating a reference image display unit that displays a plurality of reference images in the first embodiment. [Figure 13] FIG. 10 is a diagram showing an APR selection screen in the second embodiment. [Figure 14] 10A and 10B are diagrams illustrating an APR in Example 2. FIG. 10A is a diagram showing the relationship between an inspection item and an image acquisition condition associated with the inspection item, and FIG. 10B is a diagram showing each inspection item and an example of specific parameters of the image acquisition condition associated with the inspection item. [Figure 15] FIG. 10 is a diagram illustrating a reference image display unit according to step S5 of the second embodiment. [Figure 16] FIG. 10 is a diagram illustrating a display unit related to step S7 of the second embodiment. [Figure 17] FIG. 10 is a functional block diagram illustrating an outline of an X-ray device according to a third embodiment. [Figure 18] FIG. 11 is a schematic diagram showing a series of steps for reading out image acquisition conditions using a learning model and APR in the third embodiment. [Figure 19] 10 is a flowchart illustrating a series of steps in the operation of the X-ray apparatus according to the third embodiment. [Figure 20] FIG. 11 is a schematic diagram showing a series of steps for reading out image acquisition conditions when the chest is the irradiation field in Example 3. [Figure 21] FIG. 10 is a diagram illustrating a reference image display unit according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION [Example]

[0015] A first embodiment of the present invention will be described below with reference to the drawings.

[0016] <Explanation of overall configuration> 1 and 2, in the X-ray device 1 according to the first embodiment, an X-ray tube 5 and an X-ray detector 7 are arranged opposite each other across a top board 3 on which a subject M in a supine position is placed. The top board 3 is disposed on top of a top board support 4 that is configured to be movable up and down. The X-ray tube 5 irradiates X-rays onto the subject M. The X-ray detector 7 detects the X-rays that have been irradiated from the X-ray tube 5 onto and transmitted through the subject M, converts them into an electrical signal, and outputs it as an X-ray detection signal. An example of the X-ray detector 7 is an FPD (Flat Panel Detector).

[0017] The X-ray tube 5 and the X-ray detector 7 are respectively provided at one end and the other end of the C-arm 9. The C-arm 9 is held by an arm holding member 11 and is configured to rotate along an arc path of the C-arm 9 indicated by the symbol RA. That is, the C-arm 9 rotates around an axis in the y direction (the longitudinal direction of the tabletop 3) along the arc path RA.

[0018] Arm holding member 11 is disposed on the side of support column 13 and is configured to be rotatable around a horizontal axis P (arc-shaped path RB) that is parallel to the x-direction (the short-side direction of tabletop 3). C-arm 9 held by arm holding member 11 rotates around the axis in the x-direction following arm holding member 11. Because C-arm 9 is configured to be rotatable around two orthogonal axes along arc-shaped path RA and arc-shaped path RB, X-rays can be irradiated onto subject M from any direction.

[0019] The support column 13 is supported by a support base 15 disposed on the floor surface and is configured to be able to move horizontally in both the x and y directions along the upper surface of the support base 15. The arm support member 11 and C-arm 9 supported by the support column 13 move horizontally in the x or y direction in accordance with the horizontal movement of the support column 13. The collimator 17 is provided in the X-ray tube 5 and limits the X-rays emitted from the X-ray tube 5 to a predetermined shape. An example of a shape that limits the X-rays is a pyramidal cone.

[0020] As shown in FIG. 3, the X-ray device 1 further includes an image processing unit 19, a display unit 21, a storage unit 23, a main control unit 25, and an operation console 27.

[0021] The image processing unit 19 is provided after the X-ray detector 7, and generates an X-ray image based on the X-ray detection signal output from the X-ray detector 7. The display unit 21 displays the X-ray image generated by the image processing unit 19 and various information related to the X-ray device 1. Examples of the display unit 21 include a liquid crystal monitor or a high-precision display. Examples of the configuration in which the display unit 21 is arranged include a configuration in which it is suspended from the ceiling, a configuration in which it is mounted on a mobile cart, or a configuration in which it is arranged on the operation console 27.

[0022] The storage unit 23 stores various X-ray images generated by the image processing unit 19, various information related to the operation of the X-ray device 1, and the like. An example of the storage unit 23 is a non-volatile memory. The storage unit 23 includes a condition storage unit 29 and a table storage unit 31. The condition storage unit 29 stores an anatomical program 33 (APR33). The table storage unit 31 stores various tables including a standard body thickness table T1, a body thickness correction value table T2, and an average brightness table T3.

[0023] Here, the APR 33 according to the first embodiment will be described. As shown in Fig. 4(a), the APR 33 is a program in which image acquisition conditions 43 are linked to each piece of body part information 41. The body part information 41 is information that identifies the body part to be irradiated with X-rays, and examples of the body parts include the shoulders, chest, abdomen, hip joints, knees, and feet. The image acquisition conditions 43 are a series of conditions related to the acquisition of X-ray images, and include X-ray irradiation conditions 45 and image processing conditions 47.

[0024] The X-ray irradiation conditions 45 are various parameters related to X-ray irradiation. Examples of parameters related to X-ray irradiation include the tube voltage and tube current applied to the X-ray tube 5, the X-ray irradiation time, and the X-ray irradiation cycle. The image processing conditions 47 are parameters related to image processing performed on the electrical signal detected by the X-ray detector 7, and examples include a contrast processing value, a sharpening processing value, and an edge processing value. Note that the image acquisition conditions 43 may further include setting conditions for the X-ray detector 7, such as a frame rate and a gain value.

[0025] 4(b) shows specific details of image acquisition conditions 43 linked to region information 41 in APR 33 according to Example 1. As an example, region information 41a that identifies a hip joint among region information 41 is linked in advance to image acquisition conditions 43a including X-ray irradiation conditions 45a and image processing conditions 47a. Image acquisition conditions 43a include image processing conditions 47a that include parameters such as a contrast processing value of 10 and a sharpening processing value of 7. X-ray irradiation conditions 45a include parameters such as a tube voltage of 30 kV and a tube current of 2.0 mA.

[0026] Similarly, part information 41b specifying the abdomen in part information 41 is linked in advance to image acquisition conditions 43b including X-ray irradiation conditions 45b and image processing conditions 47b. Part information 41c of the chest in part information 41 is linked in advance to image acquisition conditions 43c including X-ray irradiation conditions 45c and image processing conditions 47c. Part information 41d of the shoulder in part information 41 is linked in advance to image acquisition conditions 43d including X-ray irradiation conditions 45d and image processing conditions 47d. In this way, APRs 33 in which appropriate image acquisition conditions 43 are linked to each of multiple part information 41 are set in advance and stored in condition storage unit 29.

[0027] The main control unit 25 includes an information processing unit such as a central processing unit (CPU) and controls various components of the X-ray device 1, such as the X-ray tube 5, the X-ray detector 7, the C-arm 9, and the image processing unit 19.

[0028] The main controller 25 includes a condition readout unit 35 and a reference image generator 37. The condition readout unit 35 refers to the APR 33 to read out, from the condition storage unit 29, image acquisition conditions 43 linked to region information 41 corresponding to the region selected by the operator. The condition readout unit 35 then transmits the read out image acquisition conditions 43 to the X-ray tube 5 or the image processor 19, causing the X-ray tube 5 to irradiate X-rays and the image processor 19 to generate an X-ray image in accordance with the transmitted conditions.

[0029] The reference image generating unit 37 generates a reference image Fs using the image acquisition conditions 43 most recently read by the condition reading unit 35. The reference image Fs is an X-ray image that the image processing unit 19 is expected to generate when X-rays are irradiated to a part of the subject M shown in the most recently generated X-ray image according to the most recently read image acquisition conditions 43. The reference image Fs generated by the reference image generating unit 37 is displayed on a reference image display unit 39 included in the display unit 21. In this embodiment, the display unit 21 includes multiple image display monitors, and one of the image display monitors is used as the reference image display unit 39.

[0030] The operation console 27 is used to input instructions from the operator regarding the operation of the X-ray device 1, and the main control unit 25 performs overall control in accordance with the instructions input by the operator to the operation console 27. Examples of operation devices provided on the operation console 27 include a keyboard input panel, a touch input panel, a mouse, a dial, a changeover switch, and a push button switch. Examples of locations where the operation console 27 may be provided include the side of the tabletop 3, the top of the support column 13, or a mobile cart (not shown). In the first embodiment, the operation console 27 is provided with a touch panel TP, and the touch panel TP is used to perform selection operations on the APR 33.

[0031] The reference image generating unit 37 includes a body thickness estimating unit 51, a brightness correction value calculating unit 53, and an image correcting unit 55. The body thickness estimating unit 51 estimates the body thickness of the subject M using the average brightness value of the X-ray image generated by the image processing unit 19, the image acquisition conditions 43 read by the condition reading unit 35, and a standard body thickness table T1 and a body thickness correction value table T2 stored in the table storage unit 31. The brightness correction value calculating unit 53 calculates a brightness correction value using the body thickness value estimated by the body thickness estimating unit 51 and the average brightness table T3. The image correcting unit 55 generates a reference image Fs by correcting the brightness value of the most recently generated X-ray image using the brightness correction value calculated by the brightness correction value calculating unit 53.

[0032] The following describes the various tables stored in the table storage unit 31. As shown in Fig. 5(a), the standard body thickness table T1 is a table that associates various image acquisition conditions 43 with standard body thicknesses that are predetermined for each of the image acquisition conditions 43. As an example, the image acquisition condition 43a, which is a parameter group suitable for acquiring an X-ray image of a hip joint, is associated with the standard body thickness R1.

[0033] As shown in FIG. 5(b), the body thickness correction value table T2 is a table that associates brightness differences with body thickness correction values. In this embodiment, the brightness difference refers to the difference between a predetermined standard brightness value and the average brightness value of the X-ray image F generated by the X-ray device 1. In this embodiment, the standard brightness value refers to the brightness value of an X-ray image obtained when X-rays are irradiated onto a subject with a standard body thickness by applying image acquisition condition 43. As an example, the standard brightness value when image acquisition condition 43b is set corresponds to the average brightness value of an X-ray image obtained by using image acquisition condition 43b on a subject with a standard body thickness R2.

[0034] 5(c), the average brightness table T3 is a table that associates various image acquisition conditions 43 with average brightness values ​​determined for each of the image acquisition conditions 43. The average brightness table T3 is created for each body thickness value by acquiring X-ray images using phantoms with various body thicknesses. That is, the average brightness table T3 includes, as an example, a plurality of tables such as an average brightness table T3a that is applied when the body thickness is 30 cm, an average brightness table T3b that is applied when the body thickness is 40 cm, and an average brightness table T3c that is applied when the body thickness is 50 cm.

[0035] 5(d) shows an average brightness table T3b, which is one of the average brightness tables T3, that is applied when the body thickness of the subject is 40 cm. That is, when X-ray irradiation and image processing are performed on a subject with a body thickness of 40 cm according to image acquisition condition 43d, the average brightness value of the X-ray image generated by image processing unit 19 is K4. In the X-ray device 1 according to Example 1, standard body thickness table T1, body thickness correction value table T2, and average brightness table T3 are created in advance and stored in table storage unit 31.

[0036] <Overview of operation> Here, an overview of the operation of inspecting the subject M using the X-ray device 1 will be described with reference to the flowchart shown in Fig. 6(a). Fig. 6(a) is a flowchart explaining the overview of the operation of inspecting the subject M using the X-ray device 1, and Fig. 6(b) is a flowchart further explaining the details of step S6, which is a main step.

[0037] In Example 1, a case where a percutaneous coronary intervention (PCI) is performed will be described as an example of an examination. In the coronary intervention according to Example 1, a catheter Ch is inserted from the groin, and while the catheter Ch is sequentially confirmed by X-ray fluoroscopy, the catheter Ch is guided to the coronary artery and a stent is placed. That is, the target region of the subject M to be irradiated with X-rays changes from the hip joint to the chest.

[0038] Step S1 (selection of target area) When starting a coronary intervention examination of patient M, the first step is to select the target region to be irradiated with X-rays in order to obtain the first X-ray image. That is, the operator operates the console 27 to display a target region selection screen on the touch panel TP. Figure 7 shows the touch panel TP on which the target region selection screen is displayed.

[0039] On the target region selection screen, a large number of icon groups Ac for specifying the target region are displayed on the touch panel TP. The operator selects and presses an icon from the icon group Ac to specify the region to be irradiated with X-rays. In Example 1, the first X-ray image is acquired for the hip joint region, which includes the base of the leg, so the operator selects and presses icon Ab, which specifies the hip joint. The display mode of the selected icon Ab changes compared to the other icons in the icon group Ac, as shown in FIG. 7.

[0040] Step S2 (setting image acquisition conditions) 8, information indicating that part information 41a specifying the hip joint has been selected from part information 41 is transmitted to condition reading unit 35. Condition reading unit 35 uses APR 33 stored in condition storage unit 29 to search for appropriate image acquisition conditions 43 for the part related to the received part information 41. That is, by inputting part information 41a to APR 33, image acquisition conditions 43a linked to part information 41a in APR 33 are read and output.

[0041] The read-out image acquisition conditions 43a are output from the condition read-out unit 35 and displayed in the condition display area G1 of the touch panel TP as shown in FIG. 7. For convenience of explanation, information on the tube voltage and tube current among the image acquisition conditions 43a is displayed in the condition display area G1 in FIG. 7. An adjustment key NB is displayed in the condition display area G1. By pressing the adjustment key NB, the operator can, for example, perform an adjustment to increase or decrease the value of the tube voltage from the initial value set in the image acquisition conditions 43a. Furthermore, the currently selected region information 41 (here, region information 41a) is displayed in the selected region display area G2 of the touch panel TP.

[0042] When the operator approves the image acquisition conditions 43a displayed on the touch panel TP, he or she presses the approval icon Ad located at the bottom right of the screen. By pressing the approval icon Ad, the image acquisition conditions 43a read out by the condition reading unit 35 are set as the conditions to be used for acquiring the X-ray image. Steps S1 and S2 complete the process of setting the initial image acquisition conditions 43 before starting X-ray irradiation.

[0043] Step S3 (Generation of the first X-ray image) After the initial image acquisition conditions 43a are set, the initial X-ray image is generated. That is, the operator operates the console 27 or a foot switch (not shown) to input an instruction to start X-ray irradiation. By inputting this instruction, X-ray irradiation conditions 45a among the image acquisition conditions 43a are transmitted to an X-ray tube control unit (not shown). Then, image processing conditions 47c among the image acquisition conditions 43c are transmitted to the image processing unit 19.

[0044] The X-ray tube control unit controls the X-ray tube 5 to emit X-rays from the X-ray tube 5 in accordance with the parameters of the X-ray irradiation conditions 45c. The X-ray detector 7 detects the X-rays emitted from the X-ray tube 5 and transmits a detection signal to the image processing unit 19. The image processing unit 19 performs various image processing such as contrast processing in accordance with the image processing conditions 47a to generate an X-ray image F1 of the hip joint as the target region. As shown in Figure 9 and other figures, in the X-ray image F1, the symbol Ba indicates the pelvis and the symbol Bc indicates the femur. The generated X-ray image F1 is displayed on the display unit 21. Thereafter, X-rays are intermittently irradiated by X-ray fluoroscopy, and X-ray images F1 are generated sequentially. The operator manipulates the catheter Ch so that it advances toward the heart while checking the position of the catheter Ch reflected in the X-ray image F1.

[0045] Step S4 (Reading image acquisition conditions) As the operator manipulates the catheter Ch, the position of the catheter Ch moves from the hip joint toward the chest. Therefore, in order to continue the catheterization procedure while viewing an X-ray image with higher visibility, the image acquisition conditions 43 must be changed from conditions suitable for acquiring X-ray images of the hip joint to conditions suitable for acquiring X-ray images of the chest.

[0046] Therefore, while sequentially generating X-ray images of the hip joint in accordance with the image acquisition conditions 43a, new image acquisition conditions 43 are read out. The operator causes the selection screen for APR 33 as shown in Fig. 7 to be displayed again on the touch panel TP, and selects a new target region. Here, the operator selects and presses icon Ae, which specifies the chest, from the group of icons Ac.

[0047] When icon Ae is pressed, chest region information 41c is sent to condition reading unit 35. Condition reading unit 35 inputs region information 41c to APR 33, whereby image acquisition conditions 43c linked to region information 41c are read.

[0048] Step S5 (Generation of reference image) In the case where an X-ray image of the subject M has already been generated in the X-ray device 1, when the image acquisition conditions 43 are read out by the condition reading unit 35, a reference image Fs is generated using the most recently read image acquisition conditions 43 and the most recently generated X-ray image. That is, the image acquisition conditions 43c most recently read out by the condition reading unit 35 are transmitted to the reference image generating unit 37. In addition, data of the X-ray image (here, X-ray image F1) most recently generated by the image processing unit 19 is also transmitted to the reference image generating unit 37.

[0049] The reference image generating unit 37 then performs new image processing on the X-ray image F1 showing the hip joint in accordance with the various parameters of the image acquisition conditions 43c to generate a reference image Fs. The generated reference image Fs is displayed on the reference image display unit 39 together with the most recently generated X-ray image F1, as shown in Fig. 10. The specific steps for generating the reference image Fs will be described later.

[0050] The reference image Fs is a virtual reproduction of an X-ray image that is assumed to be generated when the image acquisition conditions 43 most recently read by the condition reading unit 35 are applied to the target region of the most recently generated X-ray image. Specifically, the reference image Fs shown in Fig. 10 is a reproduction of an X-ray image that is assumed to be generated when X-rays are irradiated to the hip joint using image acquisition conditions 43c, without actually irradiating the X-rays. By visually checking the X-ray image F1 and the reference image Fs displayed on the reference image display unit 39, the operator can grasp the change in the expected appearance of the X-ray image when the image acquisition conditions 43 used to acquire the X-ray image are changed from image acquisition conditions 43a to image acquisition conditions 43c.

[0051] Step S6 (Approval of image acquisition conditions) The operator checks the appearance elements of the reference image Fs, such as brightness, contrast, and sharpness, to determine whether the image acquisition conditions 43c are appropriate image acquisition conditions 43 for the future X-ray fluoroscopy of the chest as the target region. That is, in this embodiment, in addition to the parameters of the image acquisition conditions 43, which are numerical information, the reference image Fs, which is image information, is displayed on the display unit 21. Then, the operator can use not only the numerical information but also the image information as clues to determine whether the image acquisition conditions 43 are appropriate conditions for acquiring the next X-ray image.

[0052] If the operator determines that the image acquisition conditions 43c are appropriate, he or she performs an operation to approve the image acquisition conditions 43c. By this operation, the image acquisition conditions 43c read out by the condition reading unit 35 are set as the conditions to be used for acquiring the X-ray image. Examples of an operation by the operator to approve the image acquisition conditions 43c include an operation to press the approval icon Ad and an operation to select a reference image Fs. If the reference image display unit 39 is a monitor, the operator selects the reference image Fs using a mouse or a keyboard. If the reference image display unit 39 is a touch panel, the operator selects the reference image Fs by touching the reference image Fs.

[0053] If it is determined that the image acquisition conditions 43c are inappropriate, the user returns to step S4 and selects and presses an icon specifying another target region from the icon group Ac. The image acquisition conditions 43 associated with the region information 41 corresponding to the pressed icon are read by the condition reading unit 35, and the reference image generation unit 37 again generates the reference image Fs.

[0054] Step S7 (Generation of X-ray images) When the image acquisition conditions 43c are approved by referring to the reference image Fs, an X-ray image is generated with the chest of the subject M as the target region. The operator operates the C-arm 9 to move the X-ray irradiation field from the hip joint of the subject M to the chest. Then, the operator operates the console 27 or a foot switch to start X-ray irradiation. By inputting this instruction, the X-ray irradiation conditions 45c of the image acquisition conditions 43c are sent to an X-ray tube control unit (not shown). Then, the image processing conditions 47c of the image acquisition conditions 43c are sent to the image processing unit 19.

[0055] The X-ray tube control unit controls the X-ray tube 5 to emit X-rays according to the parameters of the X-ray irradiation conditions 45c. The image processing unit 19 performs various image processing according to the image processing conditions 47c to generate an X-ray image F2 with the chest as the target region. If another image acquisition condition 43 is to be set again, the process returns to step S4 to select the target region.

[0056] As shown in Figure 11, the generated X-ray image F2 is displayed on the display unit 21. The generated chest X-ray image F2 shows the heart H, lungs Lu, and catheter Ch. X-rays are then intermittently irradiated using X-ray fluoroscopy to sequentially generate X-ray images F2. While checking the X-ray image F2, the operator operates the catheter Ch to place a stent in the coronary artery, thereby completing the PCI procedure.

[0057] <Details of the reference image generation process> Here, the process of step S5 for generating a reference image will be described in detail. Fig. 6(b) is a flowchart illustrating a series of steps relating to step S5.

[0058] Step S51 (Estimation of body thickness) When the process related to step S5 is started, the reference image generating unit 37 starts a process of estimating the body thickness of the subject M. That is, the X-ray image (here, X-ray image F1) most recently generated by the image processing unit 19 and the image acquisition conditions 43 (here, image acquisition conditions 43c) most recently read by the condition reading unit 35 are transmitted to the body thickness estimating unit 51. The body thickness estimating unit 51 also reads out the standard body thickness table T1 and the body thickness correction value table T2 stored in the table storage unit 31, and also reads out data of the standard brightness value NS stored in advance in the storage unit 23 or the like.

[0059] The body thickness estimation unit 51 first identifies the standard body thickness value using the most recently read data of the image acquisition condition 43 and the standard body thickness table T1. As shown in Fig. 5(a), in the standard body thickness table T1, the standard body thickness value corresponding to the image acquisition condition 43c is R3. Therefore, the body thickness estimation unit 51 identifies the standard body thickness value R3.

[0060] Next, the body thickness estimation unit 51 calculates the brightness difference D using the most recently generated X-ray image of the subject M and the standard brightness value NS. In this embodiment, the body thickness estimation unit 51 calculates the average brightness value N1 of the X-ray image F1, and calculates the brightness difference D by subtracting the average brightness value N1 from the standard brightness value NS. The average brightness value N1 of the X-ray image F1 is not limited to being calculated by the body thickness estimation unit 51, and may be calculated in the image processing unit 19 or by a processor in the main control unit 25 other than the body thickness estimation unit 51.

[0061] Finally, the body thickness estimation unit 51 estimates the body thickness of the subject M using the body thickness correction value table T2, the brightness difference D, and the standard body thickness value corresponding to the image acquisition condition 43. Generally, the thicker the subject, the smaller the brightness value of the X-ray image of the subject. Therefore, the larger the value obtained by subtracting the standard body thickness from the body thickness of the subject M, the larger the value obtained by subtracting the brightness value of the X-ray image of the subject M from the standard brightness value NS. As an example, when the brightness difference D is 20, the body thickness correction value is 4 cm as shown in FIG. 5(b). Therefore, the value obtained by adding 4 cm to the standard body thickness value R3 corresponding to the image acquisition condition 43c is estimated to be the body thickness of the subject M. The estimated body thickness value of the subject M is calculated as the estimated body thickness value L. The data of the estimated body thickness value L calculated by the body thickness estimation unit 51 is sent to the brightness correction value calculation unit 53.

[0062] Step S52 (calculation of brightness correction value) After the body thickness estimation unit 51 calculates the estimated body thickness value L, the brightness correction value is calculated. First, the brightness correction value calculation unit 53 refers to the estimated body thickness value L to select a table to be read out from the multiple average brightness tables T3 stored in the table storage unit 31. As an example, if the estimated body thickness value L is 40 cm, the average brightness table T3b corresponding to a body thickness of 40 cm is selected from the average brightness tables T3 and read out to the brightness correction value calculation unit 53. Note that if there is no average brightness table T3 matching the estimated body thickness value L, the average brightness table T3 corresponding to the body thickness value closest to the estimated body thickness value L is read out.

[0063] Next, the luminance correction value calculation unit 53 refers to the selected average luminance table T3, the image acquisition conditions 43 used in the most recently generated X-ray image, and the image acquisition conditions 43 most recently selected using the touch panel TP, and calculates a luminance correction value Q. In the selected average luminance table T3, if the average luminance corresponding to the image acquisition conditions 43 used in the most recently generated X-ray image is HA and the average luminance corresponding to the most recently selected image acquisition conditions 43 is HB, the luminance correction value calculation unit 53 calculates the value obtained by subtracting the average luminance HA from the average luminance HB as the luminance correction value Q. If the average luminance HA is greater than the average luminance HB, the luminance correction value Q will be a negative value.

[0064] The configuration for calculating the luminance correction value Q will be described in further detail using specific numerical examples. In Example 1, the average luminance table T3b shown in Fig. 5(d) is selected, and the image acquisition condition 43a is used for the most recently generated X-ray image F1. In the average luminance table T3b corresponding to a body thickness of 40 cm, the average luminance value corresponding to the image acquisition condition 43a is K1.

[0065] The most recently selected image acquisition condition 43 is the image acquisition condition 43c corresponding to the chest region information 41c selected in step S4. In the average brightness table T3b corresponding to a body thickness of 40 cm, the average brightness value corresponding to the image acquisition condition 43c is K3. That is, the value of the average brightness HA is K1 and the value of the average brightness HB is K3. Therefore, the brightness correction value calculation unit 53 calculates the value of (K3 - K1) as the brightness correction value Q. Data on the calculated brightness correction value Q is transmitted to the image correction unit 55. Data on the X-ray image F1, which is the X-ray image most recently generated by the image processing unit 19, is also transmitted to the image correction unit 55.

[0066] Step S53 (X-ray image correction) The image corrector 55 generates a reference image Fs using the brightness correction value Q and the data of the most recently generated X-ray image F1. Specifically, the image corrector 55 corrects the X-ray image F1 by adding the brightness correction value Q to each pixel of the X-ray image F1. When an X-ray image is acquired for a 40 cm specimen using image acquisition conditions 43a including parameters such as a tube voltage of 30 kV and a tube current of 2.0 mA, the average brightness of each pixel of the X-ray image is K1. When an X-ray image is acquired for a 40 cm specimen using image acquisition conditions 43c including parameters such as a tube voltage of 60 kV and a tube current of 3.5 mA, the average brightness of each pixel of the X-ray image is K3.

[0067] That is, when image acquisition condition 43 related to the X-ray image is changed from image acquisition condition 43a to image acquisition condition 43c, it is considered that the brightness of the X-ray image increases by the value of (K3-K1). Therefore, by adding the value of (K3-K1) to each pixel of X-ray image F1 obtained under image acquisition condition 43a, it is possible to generate a reference image Fs that takes into account the change in brightness value caused by changing each parameter from image acquisition condition 43a to image acquisition condition 43c. That is, from X-ray image F1 generated by actually irradiating the hip joint with X-rays based on image acquisition condition 43a, reference image Fs is generated as an X-ray image that is expected when X-rays are irradiated to the hip joint using image acquisition condition 43c.

[0068] Step S54 (Display of reference image) After generating the reference image Fs by correction by adding the brightness correction value Q, the data of the reference image Fs is transmitted from the image corrector 55 to the reference image display unit 39. Data of the X-ray image most recently generated by the image processor 19 is also transmitted to the reference image display unit 39. The reference image display unit 39 displays the most recently generated X-ray image F1 and the reference image Fs generated by the image corrector 55 side by side. When the reference image Fs is displayed on the reference image display unit 39, the series of operations related to step S5 is completed.

[0069] The reference image Fs is not limited to being generated based only on the image acquisition conditions 43 associated with the target region selected in step S4. In other words, multiple reference images Fs may be generated based on the image acquisition conditions 43 associated with multiple regions adjacent to the target region of the most recently generated X-ray image, or multiple regions adjacent to the target region selected in step S4.

[0070] As an example, when the chest is selected as the target region in step S4, three reference images Fs are generated and displayed based on image acquisition conditions 43 associated with the chest as well as the abdomen and shoulders, which are regions adjacent to the chest, as shown in Fig. 12. In this case, three images are displayed as reference images Fs: reference image Fs1 generated using X-ray image F1 and image acquisition condition 43c corresponding to the chest, reference image Fs2 generated using X-ray image F1 and image acquisition condition 43b corresponding to the abdomen, and reference image Fs3 generated using X-ray image F1 and image acquisition condition 43d corresponding to the shoulders.

[0071] The reference image Fs2 is a virtual X-ray image generated by performing new image processing on the X-ray image F1 showing the hip joint in accordance with the image acquisition conditions 43b corresponding to the abdomen. When the conditions for the estimated body thickness value L and the brightness difference D of the subject M are the same as those in steps S51 to S54 described above, the average brightness of the X-ray image acquired using the image acquisition conditions 43b corresponding to the abdomen is K2, as shown in FIG. 5(d). Therefore, the brightness correction value Q calculated by the brightness correction value calculation unit 53 is (K2-K1). Therefore, the image correction unit 55 adds the brightness value (K2-K1) to the brightness value of each pixel of the X-ray image F1, thereby generating the reference image Fs2.

[0072] Similarly, reference image Fs3 is a virtual X-ray image generated by applying new image processing to X-ray image F1, which shows the hip joint, in accordance with image acquisition conditions 43d corresponding to the shoulder. As shown in FIG. 5(d), the average brightness of the X-ray image acquired using image acquisition conditions 43d corresponding to the shoulder is K4. Therefore, the brightness correction value Q calculated by brightness correction value calculation unit 53 is (K4-K1). Therefore, image correction unit 55 adds the brightness value (K4-K1) to the brightness value of each pixel of X-ray image F1, thereby generating reference image Fs3.

[0073] By displaying the reference images Fs1 to Fs3 together with the X-ray image F1, the operator can visually confirm not only the expected appearance of the X-ray image when the image acquisition conditions 43 corresponding to the chest region actually selected using the console 27 are applied, but also the expected appearance of the X-ray image when the image acquisition conditions 43 corresponding to each of the target regions close to the chest region are applied. By generating reference images for multiple regions, the quality and quantity of information the operator visually obtains can be further improved. Therefore, the operator can more reliably approve the appropriate image acquisition conditions 43 and perform actual X-ray irradiation. [Example]

[0074] Next, a second embodiment of the present invention will be described. The overall configuration of an X-ray device 1A according to the second embodiment is basically the same as the overall configuration of the X-ray device 1 according to the first embodiment as shown in Fig. 1. Therefore, in the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0075] The X-ray device 1A according to the second embodiment differs from the first embodiment, which uses the APR 33, which links the image acquisition conditions 43 and the region information 41, in that the X-ray device 1A uses the APR 33A, which links the image acquisition conditions 43 and the examination item information 61. In the second embodiment, an examination item is selected instead of a target region, and a reference image Fs corresponding to the image acquisition conditions 43 linked to the selected examination item is displayed. A configuration for generating and displaying the reference image Fs in the second embodiment will be described below.

[0076] Generally, if the target region shown in the X-ray image is different, the various parameters of the image acquisition conditions 43 suitable for acquiring the X-ray image will be different. However, even if the target region of the X-ray image is the same, if the type of examination (also called examination item or procedure) performed on the target region is different, the various parameters of the image acquisition conditions 43 suitable for acquiring the X-ray image will also be different.

[0077] For example, the image acquisition conditions 43 appropriate for acquiring X-ray images differ between a case where a general X-ray is taken without introducing anything into the abdomen and a case where an endoscopic retrograde cholangiopancreatography (ERCP) is taken with an endoscope inserted into the abdomen. That is, the visibility of the X-ray image is affected by the presence or absence of the examination equipment, such as a catheter or an endoscope, and the examination agent, such as a contrast agent, and therefore the various parameters of the appropriate image acquisition conditions 43 also differ depending on the examination item.

[0078] Therefore, in the second embodiment, the touch panel TP is used to select an examination item in steps S1 and S4. FIG. 13 shows the touch panel TP on which a screen for selecting an examination item is displayed. The touch panel TP according to the second embodiment displays a large number of icon groups Bc for specifying examination items. As an example, the "chest / general" icon Ba is selected when a general X-ray examination of the chest is set as the examination item. The "chest / PCI" icon Bd is selected when a procedure for performing PCI by inserting a catheter into the chest is set as the examination item. The "abdomen / UGI" icon Bf is selected when an upper gastrointestinal X-ray examination (UGI: Upper Gastrointestinal Series) of the abdomen is set as the examination item.

[0079] Here, the APR 33A according to the second embodiment will be described. As shown in Fig. 14(a), the APR 33A is a program in which image acquisition conditions 43 are linked to each piece of examination item information 61. The examination item information 61 is information that specifies the examination item to be performed on the subject. That is, when the examination item information 61 is input to the APR 33A, the image acquisition conditions 43 corresponding to the examination item related to the examination item information 61 are output from the APR 33A.

[0080] 14(b) shows specific contents of the image acquisition conditions 43 linked to the examination item information 61 in the APR 33A according to the second embodiment. As an example, among the examination item information 61, examination item information 61a having general chest X-ray imaging as the examination item is linked in advance to image acquisition conditions 43e including X-ray irradiation conditions 45e and image processing conditions 47e. Examination item information 61b having chest PCI as the examination item is linked in advance to image acquisition conditions 43f. Examination item information 61c having abdominal general X-ray imaging as the examination item is linked in advance to image acquisition conditions 43g. Examination item information 61d having abdominal UGI as the examination item is linked in advance to image acquisition conditions 43h. In this way, in the second embodiment, the APR 33A in which appropriate image acquisition conditions 43 are linked to each of a plurality of examination item information 61 is set in advance and stored in the condition storage unit 29.

[0081] A series of steps of the operation of examining a subject M using the X-ray device 1A according to the second embodiment is the same as that of the first embodiment, except that an examination item is selected instead of a target region in steps S1 and S4. In the second embodiment, an example will be described in which a general abdominal radiography is first performed to acquire an X-ray image, and then a contrast agent is orally administered to the subject M to perform abdominal UGI X-ray radiography.

[0082] First, in step S1 according to the second embodiment, an examination item for an X-ray image to be acquired is selected. That is, the operator operates the console 27 to display an examination item selection screen on the touch panel TP (see FIG. 13). Then, the operator selects and presses an icon specifying the target examination item from the icon group Bc. In this example, the icon specifying the examination item for abdominal general radiography, i.e., the icon Bh displaying "abdomen / general", is selected and pressed.

[0083] Once the examination item is selected, the process proceeds to step S2, where the image acquisition conditions 43 used to acquire the first X-ray image are set. That is, information indicating that examination item information 61c specifying abdominal general radiography as the examination item from the examination item information 61 has been selected is transmitted to the condition reading unit 35. The condition reading unit 35 reads and outputs the image acquisition conditions 43g linked to the examination item information 61c, using the APR 33A stored in the condition storage unit 29. The read image acquisition conditions 43g are displayed in the condition display area G1 of the touch panel TP, as shown in FIG. 13. Furthermore, the examination item information 61c selected by the operator is displayed in the selected region display area G2. By pressing the approval icon Ad, the operator sets the image acquisition conditions 43g as the conditions used to acquire the X-ray image.

[0084] Once the image acquisition conditions 43g are set, the process proceeds to step S3, where the first X-ray image is acquired. That is, the operator operates the console 27 or the like to input an instruction to start X-ray irradiation. By inputting this instruction, X-ray irradiation and various image processing are performed based on the set image acquisition conditions 43g, and an X-ray image F3 of a general abdominal radiography is generated. The generated X-ray image F3 is displayed on the display unit 21. As shown in FIG. 15 etc., in the X-ray image F3, the symbol Ga indicates the stomach and the symbol Sh indicates the lumbar vertebrae.

[0085] Once the first X-ray image is acquired, the process proceeds to step S4, where the process of reading out new image acquisition conditions begins. Since the next examination item to be performed is abdominal UGI, the operator displays the selection screen of the APR 33 again on the touch panel TP and selects and presses the icon specifying abdominal UGI, i.e., icon Bf displaying "Abdomen / UGI." By pressing icon Bf, examination item information 61d for abdominal UGI is sent to the condition reading unit 35. The condition reading unit 35 inputs the examination item information 61d to the APR 33, whereby the image acquisition conditions 43h linked to the examination item information 61d are read out.

[0086] When new image acquisition conditions 43 are read, the process proceeds to step S5, where the process of generating a reference image Fs is initiated. First, data on the X-ray image F3 most recently generated by the image processing unit 19 and data on the image acquisition conditions 43h most recently read by the condition reading unit 35 are transmitted to the body thickness estimation unit 51 of the reference image generating unit 37. The body thickness estimation unit 51 estimates the body thickness of the subject M using the standard body thickness table T1, the body thickness correction value table T2, the standard brightness value NS, the average brightness value N3 of the X-ray image F3, and the image acquisition conditions 43h, and calculates an estimated body thickness value L (step S51).

[0087] Next, the brightness correction value calculation unit 53 reads out the average brightness table T3 corresponding to the estimated body thickness value L. Then, using the read out average brightness table T3, the average brightness HA corresponding to the image acquisition condition 43g used for the most recently generated X-ray image F3 and the average brightness HB corresponding to the most recently selected image acquisition condition 43h are identified. Finally, the brightness correction value calculation unit 53 calculates the brightness correction value Q by subtracting the average brightness HA from the average brightness HB (step S52).

[0088] The image corrector 55 performs correction by adding a brightness correction value Q to each pixel of the most recently generated X-ray image F3, thereby generating a reference image Fs (step S53). The generated reference image Fs is displayed on the reference image display unit 39 together with the X-ray image F3, as shown in Fig. 15 (step S54). By visually checking the X-ray image F3 and the reference image Fs, the operator can understand the expected changes in the appearance of the X-ray image when abdominal UGI is performed without administering a contrast agent or irradiating X-rays.

[0089] Once the reference image Fs is displayed, the process proceeds to step S6. The operator checks the brightness of the reference image Fs and determines whether the image acquisition conditions 43h are appropriate image acquisition conditions 43 for the abdominal UGI to be performed in the future. If the operator determines that the image acquisition conditions 43h are appropriate, the operator performs an operation to approve the image acquisition conditions 43h. This operation sets the image acquisition conditions 43h as the conditions to be used for acquiring X-ray images.

[0090] Once the new image acquisition conditions 43h are approved, the process proceeds to step S7, where an X-ray image is generated. The operator administers a contrast agent to the subject M and operates the console 27 or the like to input an instruction to start X-ray irradiation. Upon input of this instruction, X-ray irradiation and various image processing are performed based on the image acquisition conditions 43h set in step S6, and an X-ray image F4 of the abdominal UGI is generated. As shown in FIG. 16, the generated X-ray image F3 is displayed on the display unit 21. The operator checks the contrast agent Ct and the like displayed in the X-ray image F4 and completes the UGI.

[0091] In the second embodiment, the APR 33A associates the examination item information 61 with the image acquisition conditions 43. When an examination item is selected, the image acquisition conditions 43 associated with the examination item information 61 corresponding to the examination item are read out, and a reference image Fs is generated using the read out image acquisition conditions 43 and the most recently generated X-ray image, etc. With this configuration, the reference image Fs is generated not only when the target region is changed, but also when the examination item is changed due to the insertion of an endoscope or the administration of a contrast agent, etc.

[0092] That is, by selecting an examination item for a contrast agent examination before administering a contrast agent, etc., image acquisition conditions 43 corresponding to the examination item for the contrast agent examination are read out. Then, using the image acquisition conditions 43, etc., a reference image Fs is generated as an X-ray image expected when a contrast agent is administered. By visually viewing the reference image Fs, the operator can obtain visual information such as image visibility in addition to numerical information such as parameters. Therefore, it is possible to more accurately determine whether the image acquisition conditions 43 are appropriate for the examination of the subject M before administering the contrast agent. This can avoid a situation in which it is discovered that the image acquisition conditions 43 were inappropriate after administering a contrast agent and actually irradiating X-rays, requiring the administration of the contrast agent and the irradiation of X-rays to be repeated, thereby reducing the burden on the operator and the subject. [Example]

[0093] Next, a third embodiment of the present invention will be described. In the first embodiment, an operator manually selects a target region using a touch panel TP or the like. On the other hand, an X-ray device 1B according to the third embodiment automatically determines a target region shown in an X-ray image using a learning model constructed by machine learning. Here, similar to the first embodiment, the third embodiment is assumed to include an APR 33 in which region information 41 is linked to image acquisition conditions 43. Therefore, the third embodiment has a configuration in which an X-ray image is acquired and the image acquisition conditions 43 corresponding to the X-ray image are automatically read out. A configuration characteristic of the third embodiment will be described below.

[0094] 17, the X-ray device 1B according to the third embodiment includes a main control unit 25 provided with a machine learning unit 71 and an image analysis unit 73. The storage unit 23 includes a learning model storage unit 75.

[0095] The machine learning unit 71 performs machine learning using X-ray images or optical images acquired in advance to create a learning model 77. The image analysis unit 73 uses the learning model 77 to analyze the X-ray images or optical images generated by the X-ray device 1 and determine the target area shown in the image. The learning model storage unit 75 stores the learning model 77 constructed by the machine learning unit 71.

[0096] Here, a configuration of a third embodiment in which the image acquisition conditions 43 are automatically read out by acquiring an X-ray image or an optical image will be described with reference to FIG.

[0097] First, as indicated by symbol M1 in Fig. 18, a learning model 77 is created in advance. That is, the learning model 77 is created by performing machine learning in advance in the machine learning unit 71. The machine learning unit 71 acquires images of various parts of the human body in advance as original images R1. The original images R1 are, for example, a group of numerous images including X-ray images, DRR images obtained by projecting three-dimensional CT images in various directions, and optical images acquired by an optical camera.

[0098] The machine learning unit 71 then performs image processing on the original image R1 to accommodate variations in X-ray conditions, such as increases or decreases in contrast, brightness, and noise, and acquires a large number of primary augmented images R2. The machine learning unit 45 then performs image processing on the primary augmented images R2, such as rotation, enlargement, and reduction, to accommodate variations in the position of the subject M or the position of the C-arm 9, and acquires a large number of secondary augmented images R3.

[0099] Furthermore, machine learning unit 71 performs machine learning using original image R1, primary augmented image R2, and secondary augmented image R3 as training images to create learning model 77 that infers the parts of the human body that appear in the images. That is, by receiving an X-ray image F, an optical image D, or the like as input information, learning model 77 infers which parts of the human body appear in the input image, and outputs the information on the parts of the human body obtained by inference. The trained learning model 77 is stored in learning model storage unit 55.

[0100] Although the third embodiment illustrates a configuration in which the learning model 77 is created in the X-ray device 1, the learning model 77 may be created in advance in another device, and the program for the created learning model 77 may be stored in the learning model storage unit 75. In this case, the machine learning unit 71 can be omitted from the X-ray device 1.

[0101] 18, the image is analyzed to obtain information about the region shown in the image. That is, the image analysis unit 73 analyzes the image by using the learning model 77, and identifies the region of the subject M shown in the image obtained for the subject M. That is, the image analysis unit 47 reads out the learning model 77 stored in the learning model storage unit 75.

[0102] After an X-ray image of the subject M is generated by the image processing unit 19 through X-ray irradiation, the X-ray image F and the like transmitted from the image processing unit 19 are input as input images to the learning model 77. The learning model 77 analyzes the input image using clues such as the components of the human body shown in the input X-ray image, and infers the part of the subject M shown in the input image. Information about the part obtained by inference is output from the learning model 77 as part information 41. The input image is not limited to the X-ray image F, and an optical image D captured by an optical camera (not shown) or the like may also be used as the input image.

[0103] The learning model 77 analyzes the input image and outputs multiple pieces of body part information 41 together with their accuracy. When an X-ray image F1 is input to the learning model 77 as an input image, for example, the model outputs information such that the accuracy that the body part shown in the X-ray image F1 is the hip joint is 91.4%, the accuracy that the body part is the head and neck is 1.4%, the accuracy that the body part is the chest is 4.2%, and the accuracy that the body part is the abdomen is 0.1%. The output multiple pieces of body part information 41 are transmitted from the image analysis unit 73 to the condition reading unit 35 together with the accuracy information. The image analysis unit 73 does not need to transmit all of the body part information 41, but may instead select a predetermined number of pieces of body part information 41 in descending order of accuracy and transmit them to the condition reading unit 35.

[0104] 18, the condition reading unit 35 is used to read out the image acquisition conditions 43. That is, the condition reading unit 35 reads out appropriate image acquisition conditions 43 using the region information 41 obtained by the image analysis unit 73 and the APR 33. The condition reading unit 35 inputs the region information 41 obtained by the image analysis unit 73 to the APR 33, and reads out and outputs the image acquisition conditions 43 that are associated with the region information 41 and stored in the APR 33.

[0105] The output image acquisition conditions 43 are set as conditions to be used for acquiring an X-ray image immediately afterwards. The image acquisition conditions 43 newly set as conditions for acquiring an X-ray image are transmitted to the X-ray tube control unit and image processing unit 19 (not shown), and a new X-ray image of the subject M is generated in accordance with various parameters of the set image acquisition conditions 43. In this way, in the third embodiment, the most recently acquired X-ray image F or the like is used as an input image, so that the image acquisition conditions 43 to be used for acquiring an X-ray image immediately afterwards are automatically read out.

[0106] <Operation of Example 3> Here, a specific description will be given of the operation of examining the subject M using the X-ray device 3 in a state where the learning model 77 and the APR 33 are stored in the storage unit 23. Fig. 19 is a flowchart illustrating a series of steps of the operation of the X-ray device 1B according to Example 3. Example 3 will be described taking as an example a case where general X-ray examinations are performed multiple times on the chest of the subject M.

[0107] Step P1 (select the target area) When an examination of the subject M is started, a target region to be irradiated with X-rays is selected first to obtain the first X-ray image. When generating the first X-ray image, there is no input image to be analyzed by the image analysis unit 73. Therefore, in step P1, the operator manually selects the target region, similar to step S1 in the first embodiment. That is, the operator operates the console 27 to display a target region selection screen on the touch panel TP as shown in FIG. 7, and presses icon Ae to specify the desired target region, namely, the chest.

[0108] Step P2 (Setting image acquisition conditions) When a target region is selected, image acquisition conditions 43 are set according to the selected target region. The process of step P3 according to the third embodiment is similar to step S3 according to the first embodiment. That is, when icon Ae specifying the chest is pressed, information indicating that region information 41c specifying the chest has been selected is transmitted to the condition reading unit 35. The condition reading unit 35 reads image acquisition conditions 43c linked to the region information 41c using APR 33. The read image acquisition conditions 43c are displayed in the condition display area G1 of the touch panel TP. When the operator presses the approval icon Ad, the image acquisition conditions 43c read by the condition reading unit 35 are set as the conditions for acquiring the first X-ray image.

[0109] Step P3 (Generation of the first X-ray image) When the initial image acquisition conditions 43 are set, the initial X-ray image is generated. The process of step P3 according to the embodiment 3 is similar to step S3 according to the embodiment 1. That is, after the image acquisition conditions 43c are set as the initial image acquisition conditions 43, the operator operates the console 27 or the like to input an instruction to start X-ray irradiation.

[0110] 20, X-rays are irradiated from the X-ray tube 5 to the chest Lc in accordance with X-ray irradiation conditions 45c among the X-ray acquisition conditions 43c. Then, in accordance with image processing conditions 47c among the image acquisition conditions 43c, the image processing unit 19 performs various image processing on the X-ray detection signal from the X-ray detector 7. An X-ray image F5 of the target region of the chest is generated by the image processing of the image processing unit 19. The generated X-ray image F5 is displayed on the display unit 21.

[0111] Step P4 (Analysis of input image) In the X-ray device 1B according to the third embodiment, when an X-ray image is acquired, the X-ray image is analyzed and the image acquisition conditions 43 can be automatically read out. Also, a reference image can be generated using the X-ray image and the image acquisition conditions 43. Therefore, the image analysis unit 75 performs analysis on the first generated X-ray image F5 as an input image.

[0112] When step P4 starts, as shown in FIG. 20, data on X-ray image F5 is sent to image analysis unit 73 as the most recently generated X-ray image. Image analysis unit 73 inputs X-ray image F5 as an input image to learning model 77. Learning model 77 analyzes X-ray image F5, which is input information, and estimates the region shown in X-ray image F5. Information on the estimated region is output as region information 41 along with its accuracy. In this embodiment, as an example, learning model 77 estimates that the region shown in X-ray image F2 is 80% certain to be the chest, 15% certain to be the abdomen, and 5% certain to be the hip joint. As a result, learning model 77 outputs region information 41c specifying the chest, region information 41b specifying the abdomen, and region information 41a specifying the hip joint along with their respective accuracy, and transmits these to condition reading unit 35.

[0113] Step P5 (Reading image acquisition conditions) When the input image is analyzed and region information 41 is output, image acquisition conditions 43 are read using the region information 41 and APR 33. That is, as shown in FIG. 20 , condition reading unit 35 inputs the received region information 41a-41c to APR 33 and searches for image acquisition conditions 43 corresponding to each of region information 41a-41c. Image acquisition condition 43a is linked to region information 41a. Image acquisition condition 43b is linked to region information 41b, and image acquisition condition 43c is linked to region information 41c. Therefore, condition reading unit 35 reads image acquisition conditions 43a, 43b, and 43c. In this way, when the first X-ray image F5 is generated, image acquisition conditions 43a-43c are automatically read in steps P4 and P5. The automatically read image acquisition conditions 43a-43c are transmitted from condition reading unit 35 to reference image generating unit 37. Further, the reference image generating unit 37 is sent data of the most recently generated X-ray image, that is, the X-ray image F5.

[0114] Step P6 (Generation of reference image) When the most recently read image acquisition conditions 43 (here, image acquisition conditions 43a to 43c) and data of the most recently generated X-ray image are transmitted to the reference image generation unit 37, a process of generating a reference image Fs in step P6 is started. The process in step P6 is common to the process in step S5 in the first embodiment.

[0115] In this embodiment, three image acquisition conditions 43a, 43b, and 43c have been most recently read, so three types of reference images Fs are generated for each of the image acquisition conditions 43a to 43c. That is, a first reference image FsA is generated by performing new image processing on an X-ray image F5, which is an image of a general chest X-ray, in accordance with various parameters of the image acquisition condition 43a.

[0116] The specific process for generating the reference image FsA is as follows. First, the body thickness estimation unit 51 uses the data of the most recently read image acquisition conditions 43a and the standard body thickness table T1 to identify the standard body thickness value R1 corresponding to the image acquisition conditions 43a, as shown in FIG. 5(a). Then, the body thickness estimation unit 51 calculates the brightness difference D by subtracting the average brightness value of the most recently generated X-ray image F5 from the standard brightness value predetermined according to the standard body thickness R1 and the image acquisition conditions 43a. Finally, the body thickness estimation unit 51 calculates the estimated body thickness value L of the subject M using the body thickness correction value table T2, the brightness difference D, and the standard body thickness value R1 (see step S51). Next, the brightness correction value calculation unit 53 calculates the brightness correction value Q1 using the estimated body thickness value L, the average brightness table T3, the image acquisition conditions 43c used for the most recently generated X-ray image F5, and the most recently read image acquisition conditions 43a (see step S52). The image corrector 55 then adds the brightness correction value Q1 to the brightness value of each pixel of the X-ray image F5 to generate a reference image FsA.

[0117] Similarly, a second reference image FsB is generated by performing new image processing based on X-ray image F5 in accordance with the various parameters of image acquisition conditions 43b. A third reference image FsC is generated by performing new image processing based on X-ray image F5 in accordance with the various parameters of image acquisition conditions 43c. However, when generating reference image FsB, the data of image acquisition conditions 43b is used as the most recently read image acquisition conditions 43. And when generating reference image FsB, the data of image acquisition conditions 43c is used as the most recently read image acquisition conditions 43.

[0118] As shown in Fig. 21, each of the generated reference images FsA, FsB, and FsC is displayed on the reference image display unit 39 together with the X-ray image F5 most recently generated by the image processing unit 19. Reference image FsA is an X-ray image that is assumed to be generated when X-rays are irradiated onto the chest as a target region using image acquisition condition 43a. Reference image FsB is an X-ray image that is assumed to be generated when X-rays are irradiated onto the chest as a target region using image acquisition condition 43b.

[0119] Step P7 (Approval of image acquisition conditions) The operator visually checks the reference images FsA to FsC and the X-ray image F5 displayed on the reference image display unit 39 to determine which of the image acquisition conditions 43a to 43c is most appropriate as the image acquisition conditions 43 to be used for acquiring the next X-ray image. The operator then selects the image acquisition conditions 43 determined to be most appropriate and performs an operation to approve them. For example, if the operator determines that the image acquisition conditions 43b are appropriate, the operator approves the image acquisition conditions 43b by performing an operation such as clicking the reference image FsB with the mouse. By performing an operation to indicate approval, the approved image acquisition conditions 43b are set as the image acquisition conditions 43 to be used when acquiring the second X-ray image.

[0120] Step P8 (Generating X-ray images) Once image acquisition conditions 43b are set, the next X-ray image is generated. That is, after adjusting the position of the X-ray irradiation field by adjusting the position of the C-arm 9 as appropriate, a command to irradiate X-rays is input using the console 27 or the like, thereby performing a second X-ray irradiation. That is, X-rays are irradiated according to X-ray irradiation conditions 45b of the image acquisition conditions 43b, and the image processing unit 19 performs image processing according to image processing conditions 47b. As a result, a second X-ray image F6 is generated based on the image acquisition conditions 43b. The X-ray image F6 is displayed on the display unit 21.

[0121] When generating a third X-ray image, the process returns to step P4 and repeats the operations of steps P4 to P8. In step P4, the image processing unit 19 inputs the most recently generated X-ray image F6 as an input image to the learning model 77, and the image analysis unit 73 analyzes the input image X-ray image F6. As a result of the analysis, three pieces of region information 41 are output in descending order of accuracy. In step P5, the image acquisition conditions 43 associated with each piece of region information 41 output by the analysis of the X-ray image F6 are read. In step P6, a reference image is generated using each of the image acquisition conditions 43 read in step P5, based on the most recently generated X-ray image F6. In step P7, the three reference images are checked, and appropriate image acquisition conditions 43 are selected and approved for acquiring the third X-ray image.

[0122] In the third embodiment, a learning model 77 constructed by machine learning is used to analyze the most recently generated X-ray image, thereby automatically determining region information 41 that identifies the target region of the X-ray image. In the third embodiment, the operator does not need to manually operate the touch panel TP or the like to select the target region. In other words, it is possible to avoid interrupting the progress of the examination or surgery to manually select the target region, and it is also possible to avoid having to redo the selection operation of the target region or the examination itself due to an operator's selection error, so that X-ray fluoroscopy or X-ray imaging can be performed more reliably and quickly under appropriate conditions.

[0123] <Effects of the configuration of the embodiment> (Item 1) An X-ray device (1) according to a first embodiment includes an X-ray tube (5) that irradiates an object (M) with X-rays, an X-ray detector (7) that is disposed opposite the X-ray tube and detects X-rays that have passed through the object, an image processing unit (19) that generates an X-ray image by performing image processing using a detection signal output by the X-ray detector, a condition storage unit (29) that stores image acquisition conditions (43) including at least one of X-ray irradiation conditions (45) and image processing conditions (47) corresponding to each of a plurality of parts of the object in association with part information (41) that identifies any of the parts, and a plurality of parts of the object. The apparatus includes an input unit (27) capable of inputting an instruction to select a region to be irradiated with X-rays on the subject as the region information (41), a condition reading unit (35) that reads out the image acquisition conditions (43) stored in the condition storage unit in association with the region information (41) when the region information (41) is selected by the input unit, a reference image generation unit (37) that performs image processing on the most recently generated X-ray image based on the image acquisition conditions read out by the condition reading unit to generate a reference image (Fs), and a reference image display unit (39) that displays the reference image generated by the reference image generation unit.

[0124] According to the X-ray device 1 described in paragraph 1, by selecting a region of the subject to be irradiated with X-rays as region information, image acquisition conditions associated with the region information are read, and a reference image is generated and displayed on the reference image display unit. The reference image is obtained by applying the read image acquisition conditions to the most recently generated X-ray image and performing image processing. Therefore, by visually checking the reference image, the operator can roughly grasp in advance how the generated X-ray image will look when image acquisition conditions corresponding to the target region selected on the input unit are applied. In other words, by visually checking the reference image, the operator can predict the level of various conditions such as brightness and contrast of the X-ray image, which can more reliably avoid a situation where image acquisition conditions that are actually inappropriate parameters are executed and the image acquisition conditions have to be reconfigured. Therefore, appropriate image acquisition conditions can be set more reliably and quickly to perform X-ray fluoroscopy or X-ray imaging.

[0125] (Item 2) In the X-ray device described in item 1, a learning model storage unit (75) stores a learning model (77) that performs machine learning using an image of a human body as a teacher image to infer and output a part of the human body shown in the image; an image analysis unit (73) that inputs at least one of the X-ray image (F) and the optical image (D) of the subject obtained most recently as an input image into the learning model, analyzes the input image, infers the part shown in the input image, and outputs information that identifies the inferred part as the part information; and the condition reading unit (35) and a control unit (25) that controls at least one of the following: controlling the X-ray tube (5) so that X-rays are irradiated in accordance with the X-ray irradiation conditions (45) read out by the condition reading unit (35); and controlling the image processing unit (19) so that the X-ray image is generated in accordance with the image processing conditions (47) read out by the condition reading unit (35). The condition reading unit (35) is configured to select the part output by the image analysis unit (73) as the part information (41), and to read out the image acquisition conditions (43) stored in the condition storage unit (29) in association with the part information (41).

[0126] According to the X-ray apparatus described in paragraph 2, the image acquisition conditions 43 are automatically set by using a learning model 77. The learning model 77 is configured to infer and output a region of the human body shown in an image by machine learning using an image of the human body as a training image. That is, the image analysis unit 73 inputs an image of the subject M as an input image to the learning model 77, thereby inferring the region of the subject shown in the input image, and outputs information identifying the inferred region as region information. The condition reading unit 35 selects the output region information 41 of the subject M, thereby automatically reading out the image acquisition conditions 43 associated with the region information 41 and stored. Therefore, when an X-ray image F of the subject is acquired, the image analysis unit 73 and the condition reading unit 35 automatically read out the image acquisition conditions 43 appropriate for the position of the irradiation field of the X-ray image F. Therefore, even if the region of the subject M to be irradiated with X-rays is changed, the image acquisition conditions 43 appropriate for the changed region are automatically read out. That is, the process of the operator manually selecting the target region and setting the image acquisition conditions 43 is no longer necessary, so that X-ray fluoroscopy or X-ray photography can be performed more reliably and quickly under appropriate conditions.

[0127] (Item 3) The X-ray apparatus according to item 1 or 2 further comprises a table storage unit (31) for storing a standard body thickness table (T1) associating the image acquisition conditions (43) with standard body thicknesses determined in accordance with the image acquisition conditions, a body thickness correction value table (T2) associating a brightness difference (D) obtained by subtracting an average brightness value (N1) of an X-ray image (F1) most recently generated by the image processing unit (19) from a predetermined standard brightness value (NS) with a body thickness correction value, and an average brightness table (T3) created in plurality according to the body thickness of the subject and associating the image acquisition conditions with average brightnesses determined in accordance with the image acquisition conditions, and the reference image generation unit (37) stores the image acquisition conditions (43c) most recently read by the condition reading unit (35), the body thickness correction value table (T2) most recently generated by the image processing unit (19), and the reference image generation unit (37) stores the image acquisition conditions (43c) most recently read by the condition reading unit (35), the body thickness correction value table (T2) most recently generated by the image processing unit, and the reference image generation unit (37) stores the standard body thickness table (T1) associating the image acquisition conditions (43c) with standard body thicknesses determined in accordance with the image acquisition conditions, and the reference image generation unit (37) stores the standard body thickness table (T2) associating the brightness difference (D) obtained by subtracting an average brightness value (N1) of an X-ray image (F1) most recently generated by the image processing unit (19) from a predetermined standard brightness value (NS), with a body thickness correction value. the body thickness estimation unit (51) estimating the body thickness of the subject using the X-ray image (F1) most recently generated, the standard body thickness table (T1), and the body thickness correction value table (T2), and calculating the estimated body thickness of the subject as an estimated body thickness value (L); a brightness correction value calculation unit (53) calculating a brightness correction value (Q) using the average brightness table (T3b) corresponding to the estimated body thickness value (L), the image acquisition conditions (43a) used for the X-ray image (F1) most recently generated by the image processing unit, and the image acquisition conditions (43c) most recently read out by the condition reading unit; and an image correction unit (55) generating the reference image (Fs) by adding the brightness correction value (Q) to each pixel of the X-ray image (F1) most recently generated by the image processing unit.

[0128] According to the X-ray fluoroscopy apparatus described in paragraph 3, the body thickness estimation unit estimates the subject's body thickness using a standard body thickness table, a body thickness correction value table, etc. The brightness correction value calculation unit calculates a brightness correction value using the estimated body thickness value of the subject and an average brightness table, etc. The image correction unit generates a reference image by adding a brightness correction value to each pixel of the X-ray image most recently generated by the image processing unit. In this case, even if the subject's body thickness is outside the standard range, the body thickness estimation unit estimates the subject's body thickness and calculates an appropriate brightness correction value according to the estimated body thickness. Therefore, since the brightness value correction of the most recently generated X-ray image performed to generate the reference image is appropriately performed, the reference image more accurately reproduces an image expected as a clinical image of the subject. Therefore, even if the subject's body thickness is outside the standard range, the operator can more reliably and quickly set appropriate image acquisition conditions and perform X-ray fluoroscopy or X-ray imaging.

[0129] (Item 4) An X-ray device (1A) according to the second embodiment includes an X-ray tube (5) that irradiates an object (M) with X-rays, an X-ray detector (7) that is disposed opposite the X-ray tube and detects X-rays that have passed through the object, an image processing unit (19) that performs image processing using a detection signal output by the X-ray detector to generate an X-ray image, a condition storage unit (29) that stores image acquisition conditions (43) that include at least one of X-ray irradiation conditions (45) and image processing conditions (47) corresponding to each of a plurality of examination items on the object, in association with the examination items (61), and an examination time (T) to be performed on the object. an input unit (27) capable of inputting an instruction to select a type of X-ray image (F1) as an examination item (61); a condition reading unit (35) that reads out the image acquisition conditions (43) stored in the condition storage unit in association with the examination item when the examination item is selected by the input unit; a reference image generating unit (37) that performs image processing on the most recently generated X-ray image (F1) based on the image acquisition conditions (43) read out by the condition reading unit to generate a reference image (Fs); and a reference image display unit (39) that displays the reference image generated by the reference image generating unit.

[0130] According to the X-ray device described in paragraph 4, by selecting the type of examination to be performed on the subject as an examination item, image acquisition conditions associated with the examination item are read out, and a reference image is generated and displayed on the reference image display unit. The reference image is obtained by applying the read-out image acquisition conditions to the most recently generated X-ray image and performing image processing. Therefore, by visually checking the reference image, the operator can obtain information in advance about how the generated X-ray image will look when the image acquisition conditions corresponding to the target region selected on the input unit are applied. In other words, by visually checking the reference image, the operator can predict the level of various conditions, such as brightness and contrast, of the X-ray image. This more reliably prevents the execution of image acquisition conditions that are actually inappropriate parameters, resulting in the need to redo the image acquisition conditions. Therefore, appropriate image acquisition conditions can be set more reliably and quickly to perform X-ray fluoroscopy or X-ray imaging.

[0131] (Item 5) The X-ray device according to item 4 further includes a learning model storage unit (75) for storing a learning model (77) that performs machine learning using an examination image of a human body as a teacher image to infer and output the type of examination in the examination image; an image analysis unit (73) that inputs at least one of the X-ray image (F) and optical image (D) of the subject obtained most recently into the learning model (77) as an input image, analyzes the input image, and infers and outputs the type of examination in the input image; and and a control unit (25) that controls at least one of the X-ray tube (5) so that X-rays are irradiated in accordance with ray irradiation conditions (45) and the image processing unit (19) so that the X-ray image is generated in accordance with the image processing conditions (47) read out by the condition reading unit, and the condition reading unit (35) is configured to select the type of examination output by the image analysis unit (73) as the examination item (61) and read out the image acquisition conditions (43) that are linked to the examination item and stored in the condition storage unit (29).

[0132] According to the X-ray apparatus described in paragraph 5, the image acquisition conditions 43 are automatically set by using a learning model 77. The learning model 77 is configured to infer the type of examination shown in the image by machine learning using an image of a human body as a teacher image, and output the inferred type of examination as examination item information 61. That is, the image analysis unit 73 inputs an image of the subject M as an input image to the learning model 77, thereby inferring the part of the subject shown in the input image, and outputs information specifying the inferred type of examination as examination item information 61. The condition reading unit 35 selects the output examination item information 61 of the subject M, and automatically reads out the image acquisition conditions 43 that have been stored in association with the examination item information 61.

[0133] Therefore, when an X-ray image F of a subject is acquired, the image analysis unit 73 and the condition reading unit 35 automatically read out image acquisition conditions 43 appropriate for the examination items of the X-ray image F. Therefore, even if the examination items for the subject M are changed due to the insertion of an endoscope or a catheter, the administration of a contrast agent, or the like, the image acquisition conditions 43 appropriate for the changed examination items are automatically read out. In other words, this eliminates the need for the operator to manually select the target area and set the image acquisition conditions 43 every time the examination items are changed, making it possible to more reliably and quickly perform X-ray fluoroscopy or X-ray imaging under appropriate conditions.

[0134] (Item 6) The X-ray apparatus according to item 4 or 5 further comprises a table storage unit (31) for storing a standard body thickness table (T1) associating the image acquisition conditions (43) with standard body thicknesses determined in accordance with the image acquisition conditions, a body thickness correction value table (T2) associating a brightness difference (D) obtained by subtracting an average brightness value (N1) of an X-ray image (F1) most recently generated by the image processing unit (19) from a predetermined standard brightness value (NS) with a body thickness correction value, and an average brightness table (T3) created in plurality according to the body thickness of the subject and associating the image acquisition conditions with average brightnesses determined in accordance with the image acquisition conditions, and the reference image generation unit (37) stores the image acquisition conditions (43c) most recently read out by the condition reading unit (35), the body thickness correction value table (T2) most recently generated by the image processing unit (19), and the reference image generation unit (37) stores the image acquisition conditions (43c) most recently read out by the condition reading unit (35), the body thickness correction value table (T2) most recently generated by the image processing unit, and the reference image generation unit (37) stores the standard body thickness table (T1) associating the image acquisition conditions (43c) with standard body thicknesses determined in accordance with the image acquisition conditions, and the reference image generation unit (37) stores the standard body thickness table (T2) associating the brightness difference (D) obtained by subtracting an average brightness value (N1) of an X-ray image (F1) most recently generated by the image processing unit from a predetermined standard brightness value (NS), and the body thickness correction value. the body thickness estimation unit (51) estimating the body thickness of the subject using the X-ray image (F1) most recently generated, the standard body thickness table (T1), and the body thickness correction value table (T2), and calculating the estimated body thickness of the subject as an estimated body thickness value (L); a brightness correction value calculation unit (53) calculating a brightness correction value (Q) using the average brightness table (T3b) corresponding to the estimated body thickness value (L), the image acquisition conditions (43a) used for the X-ray image (F1) most recently generated by the image processing unit, and the image acquisition conditions (43c) most recently read out by the condition reading unit; and an image correction unit (55) generating the reference image (Fs) by adding the brightness correction value (Q) to each pixel of the X-ray image (F1) most recently generated by the image processing unit.

[0135] According to the X-ray fluoroscopy apparatus described in paragraph 6, the body thickness estimation unit estimates the body thickness of the subject using a standard body thickness table, a body thickness correction value table, etc. The brightness correction value calculation unit calculates a brightness correction value using the estimated body thickness value of the subject and an average brightness table, etc. The image correction unit generates a reference image by adding a brightness correction value to each pixel of the X-ray image most recently generated by the image processing unit. In this case, even if the body thickness of the subject is outside the standard range, the body thickness estimation unit estimates the body thickness of the subject and calculates an appropriate brightness correction value according to the estimated body thickness. Therefore, since the brightness value correction of the most recently generated X-ray image performed to generate the reference image is appropriately performed, the reference image more accurately reproduces an image expected as a clinical image of the subject. Therefore, even if the body thickness of the subject is outside the standard range, the operator can more reliably and quickly set appropriate image acquisition conditions and perform X-ray fluoroscopy or X-ray imaging.

[0136] <Other embodiments> It should be noted that the embodiments disclosed herein are illustrative in all respects and are not limiting. The scope of the present invention includes the claims and all modifications within the meaning and scope of the claims. For example, the present invention can be modified as follows:

[0137] (1) In the above-described embodiments, the reference image Fs is an X-ray image (clinical image) of the subject M to be irradiated with X-rays. However, the reference image Fs may be an X-ray image (phantom image) of a phantom. That is, when the reference image Fs is a clinical image as in each embodiment, the most recently generated clinical image does not exist when the first X-ray image is generated. Therefore, in each embodiment in which the reference image Fs is a clinical image, the reference image Fs is not displayed when the image acquisition conditions 43 are read in step S2.

[0138] On the other hand, in a modified example in which a phantom image is used as the reference image Fs, a phantom image of an average body thickness is irradiated with X-rays under various image acquisition conditions 43, thereby acquiring phantom images corresponding to the various image acquisition conditions 43 in advance as reference images Fs. A series of acquired phantom images is stored in the storage unit 23. Then, when image acquisition condition 43b is selected as an example in step S1 to acquire an X-ray image of the subject M, and image acquisition condition 43b is read in step S2, the reference image generation unit 37 reads out a phantom image generated based on image acquisition condition 43b from the storage unit 23 between steps S2 and S3. The read-out phantom image is then displayed on the reference image display unit 39 as the reference image Fs.

[0139] The operator checks the brightness of the phantom image displayed as the reference image Fs, determines whether the image acquisition conditions 43b are appropriate for acquiring the first X-ray image, and approves the image acquisition conditions 43b if they are deemed appropriate. After approval, the operator starts X-ray irradiation to actually generate the first X-ray image.

[0140] In this modified example, since the reference image Fs can be confirmed even when preparing to acquire the first X-ray image, it is not necessary to judge the suitability of the image acquisition conditions 43 only by numerical parameters at the preparation stage for acquiring the first X-ray image. Therefore, the suitability of the image acquisition conditions 43 can be determined more accurately even at the stage of generating the first X-ray image.

[0141] In a modified example in which a phantom image is used as the reference image, when acquiring the second and subsequent X-ray images, the reference image Fs may be switched from the phantom image to a clinical image of the subject M. That is, the phantom image is used as the reference image only at the stage of generating the first X-ray image. Then, at the stage of generating the second X-ray image, a clinical image is generated by applying the most recently read image acquisition condition 43 based on the first X-ray image showing the subject M, as in the first embodiment, and is displayed as the reference image Fs.

[0142] Since the clinical image is an X-ray image of the subject M himself, it is possible to select an appropriate image acquisition condition 43 with higher accuracy even when, for example, the body thickness of the subject M is outside the standard range. Therefore, if the X-ray device 1 is configured to switch the reference image between a phantom image and a clinical image, it is possible to display the phantom image as the reference image even at the stage of acquiring the first X-ray image when there is no clinical image of the subject M, and at the stage of acquiring the second and subsequent X-ray images, it is possible to display the clinical image as the reference image, thereby further improving the accuracy of the information obtained from the reference image.

[0143] In a modified example in which a phantom image is used as the reference image, the phantom image may be continuously used as the reference image Fs when acquiring the second and subsequent X-ray images. When the X-ray device 1 is configured to display only a phantom image as the reference image, there is no need to calculate the estimated body thickness value L or the brightness correction value Q in the step of generating the reference image Fs, and therefore the reference image generating unit 37 does not need to include the body thickness estimating unit 51 and the brightness correction value calculating unit 53. In other words, there is no need to perform complex calculations when generating a reference image, which reduces the burden on processors such as the main control unit 25.

[0144] (2) In each of the above-described embodiments, the image acquisition conditions 63 are not limited to a configuration including both the X-ray irradiation conditions 65 and the image processing conditions 67, and may be a configuration including either one of them. Furthermore, the X-ray irradiation conditions 65 may be a configuration including, independently, or including either one of the X-ray fluoroscopy conditions, which are a group of parameters used for X-ray fluoroscopy in which a relatively weak dose of X-rays is intermittently irradiated, and the X-ray imaging conditions, which are a group of parameters used for X-ray imaging in which a relatively strong dose of X-rays is irradiated in a single shot.

[0145] (3) In each of the above-described embodiments, an X-ray fluoroscopic imaging device equipped with a C-arm 9 is used as an example of the X-ray device 1, but this is not limited thereto, and the configuration of the present invention can be applied to any radiation imaging device, such as an X-ray imaging device for general X-ray imaging or a tomography imaging device.

[0146] (4) In the above-described third embodiment, the X-ray image F used as input information to be input to the learning model 77 may be an X-ray fluoroscopic image or an X-ray radiographic image. Alternatively, an X-ray fluoroscopic image may be input to the learning model 77 as input information, and X-ray radiography may be performed using the image acquisition conditions 43 output from the APR 33. Alternatively, an X-ray radiographic image may be input to the learning model 77 as input information, and X-ray fluoroscopy may be performed using the image acquisition conditions 43 output from the APR 33.

[0147] (5) In the above-described third embodiment, the configuration in which the operator manually selects the target region at the stage of acquiring the first X-ray image (the stage before X-rays are irradiated) has been described as an example, but this is not limited thereto. That is, the X-ray device 1B may be provided with an optical camera (not shown) arranged to have the same irradiation angle as the X-ray tube 5, and the optical camera may acquire an optical image D of the subject M at the stage before X-rays are irradiated, and the optical image D may be used as the input image. In a configuration including an optical camera, inference is performed using the learning model 77 with the optical image D, not the X-ray image F, as the input image at the stage of acquiring the first X-ray image. Therefore, the operator's manual operation of selecting the target region can be omitted even at the stage of acquiring the first X-ray image. [Explanation of symbols]

[0148] 1. X-ray fluoroscopy equipment 3. Top plate 5...X-ray tube 7...X-ray detector 9...C-arm 17...Collimator 19...Image processing section 21...Display section 23...Storage section 25...Main control unit 27...Operation console 29…Condition storage section 31...Table storage section 33...Anatomical Program (APR) 35...Condition reading section 37...Reference image generation unit 39...Reference image display section 41 …part information 43...Image acquisition conditions 45...X-ray irradiation conditions 47...Image processing conditions 51...Body thickness estimation section 53 ... Brightness correction value calculation unit 55...Image correction section T1...Standard thickness table T2: Body thickness correction value table T3...Average luminance table Ac...Icons TP...Touch panel L: Estimated body thickness Q: Brightness correction value

Claims

1. an X-ray tube that irradiates an object with X-rays; an X-ray detector disposed opposite the X-ray tube and configured to detect X-rays transmitted through the subject; an image processing unit that generates an X-ray image by performing image processing using the detection signal output by the X-ray detector; a storage unit that stores image acquisition conditions including at least one of X-ray irradiation conditions and image processing conditions corresponding to each of a plurality of regions in the subject, in association with region information that is information specifying any one of the regions, and stores the X-ray image generated based on the image acquisition conditions associated with the first region information; an input unit capable of inputting an instruction to select a region of the subject to be irradiated with X-rays from a plurality of regions of the subject as region information; a condition reading unit that reads out the image acquisition conditions that are associated with the region information and stored in the storage unit when the region information is selected by the input unit; a reference image generating unit that generates a reference image by performing image processing on the X-ray image generated based on the image acquisition conditions associated with the first portion information stored in the storage unit, based on the image acquisition conditions associated with second portion information different from the first portion information read by the condition reading unit; and a reference image display unit that displays the reference image generated by the reference image generation unit; An X-ray device comprising:

2. 2. The X-ray apparatus according to claim 1, a learning model storage unit that stores a learning model that infers and outputs a part of the human body shown in an image by performing machine learning using an image of the human body as a teacher image; an image analysis unit that inputs at least one of the most recently obtained X-ray image and optical image of the subject as an input image into the learning model, analyzes the input image, and infers and outputs a region shown in the input image; control of the X-ray tube so that X-rays are irradiated in accordance with the X-ray irradiation conditions read by the condition reading unit; and a control unit that controls at least one of the image processing unit and the image processing unit so that the X-ray image is generated in accordance with the image processing conditions read by the condition reading unit. Equipped with The condition reading unit is configured to select the region output by the image analysis unit as the region information, and to read out the image acquisition conditions stored in the memory unit in association with the region information.

3. 3. The X-ray apparatus according to claim 1, a table storage unit for storing a standard body thickness table associating the image acquisition conditions with standard body thicknesses determined according to the image acquisition conditions, a body thickness correction value table associating a brightness difference, which is a value obtained by subtracting an average brightness value of an X-ray image most recently generated by the image processing unit from a predetermined standard brightness value, with a body thickness correction value, and a plurality of average brightness tables created according to the body thickness of the subject, each of which associates the image acquisition conditions with average brightnesses determined according to the image acquisition conditions, The reference image generation unit a body thickness estimation unit that estimates a body thickness of the subject using the image acquisition conditions most recently read by the condition reading unit, the X-ray image most recently generated by the image processing unit, the standard body thickness table, and the body thickness correction value table, and calculates the estimated body thickness of the subject as an estimated body thickness value; a brightness correction value calculation unit that calculates a brightness correction value using the average brightness table corresponding to the estimated body thickness value, the image acquisition conditions used in the X-ray image most recently generated by the image processing unit, and the image acquisition conditions most recently read by the condition reading unit; an image correction unit that generates the reference image by adding the luminance correction value to each pixel of the X-ray image most recently generated by the image processing unit; An X-ray device comprising:

4. an X-ray tube that irradiates an object with X-rays; an X-ray detector disposed opposite the X-ray tube and configured to detect X-rays transmitted through the subject; an image processing unit that generates an X-ray image by performing image processing using the detection signal output by the X-ray detector; a storage unit that stores image acquisition conditions including at least one of X-ray irradiation conditions and image processing conditions corresponding to each of a plurality of examination items on the subject, in association with the examination items, and stores the X-ray image generated based on the image acquisition conditions associated with a first of the examination items; an input unit capable of inputting an instruction to select the type of test to be performed on the subject as a test item; a condition reading unit that reads out the image acquisition conditions that are associated with the inspection item and stored in the storage unit when the inspection item is selected by the input unit; a reference image generating unit that generates a reference image by performing image processing on the X-ray image generated based on the image acquisition conditions associated with the first examination item stored in the storage unit, based on the image acquisition conditions associated with the second examination item different from the first examination item read by the condition reading unit; and a reference image display unit that displays the reference image generated by the reference image generation unit; An X-ray device comprising:

5. 5. The X-ray apparatus according to claim 4, a learning model storage unit that stores a learning model that infers and outputs the type of examination in an examination image by performing machine learning using an examination image showing a human body as a teacher image; an image analysis unit that analyzes at least one of the X-ray image and the optical image of the subject most recently obtained by inputting the image into the learning model as an input image, and infers and outputs the type of examination for the input image; a control unit that controls at least one of the X-ray tube so that X-rays are irradiated in accordance with the X-ray irradiation conditions read by the condition readout unit, and the image processing unit so that the X-ray image is generated in accordance with the image processing conditions read out by the condition readout unit; Equipped with The condition reading unit is configured to select the type of examination output by the image analysis unit as the examination item, and to read out the image acquisition conditions stored in the memory unit in association with the examination item.

6. 6. The X-ray apparatus according to claim 4, a standard body thickness table associating the image acquisition conditions with standard body thicknesses determined in accordance with the image acquisition conditions; a body thickness correction value table associating a body thickness correction value with a brightness difference, which is a value obtained by subtracting a predetermined standard brightness value from an average brightness value of an X-ray image most recently generated by the image processing unit; and a table storage unit that stores a plurality of average brightness tables created in accordance with the body thickness of the subject, each of which associates the image acquisition conditions with average brightnesses determined in accordance with the image acquisition conditions; The reference image generation unit a body thickness estimation unit that estimates a body thickness of the subject using the image acquisition conditions most recently read by the condition reading unit, the X-ray image most recently generated by the image processing unit, the standard body thickness table, and the body thickness correction value table, and calculates the estimated body thickness of the subject as an estimated body thickness value; a brightness correction value calculation unit that calculates a brightness correction value using the average brightness table corresponding to the estimated body thickness value, the image acquisition conditions used in the X-ray image most recently generated by the image processing unit, and the image acquisition conditions most recently read by the condition reading unit; an image correction unit that generates the reference image by adding the luminance correction value to each pixel of the X-ray image most recently generated by the image processing unit; An X-ray device comprising:

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