X-ray imaging system and X-ray image display method

Abstract

The present invention provides an X-ray imaging system and an X-ray image display method that can reduce the effort required to change the orientation of the target area of ​​a subject in the X-ray image displayed on the display unit. [Solution] This X-ray imaging system 100 comprises an X-ray irradiation unit 11, an X-ray detection unit 12, a display unit 20, and a control unit 30. The control unit 30 acquires a discrimination image in which a target area 91 of the subject 90 has been photographed, and determines the orientation of the target area 91 in the acquired discrimination image. The control unit 30 then changes the orientation of the target area 91 of the subject 90 in the X-ray image 50 displayed on the display unit 20 by performing at least one of the following processes: rotating the target area 91 in the X-ray image 50 displayed on the display unit 20 so that it faces a predetermined display direction, and inverting the target area 91 in the X-ray image 50 displayed on the display unit 20.

Description

Technical Field

[0001] The present invention relates to an X-ray imaging system and an X-ray image display method.

Background Art

[0002] Conventionally, X-ray imaging devices have been known (see, for example, Patent Document 1).

[0003] Patent Document 1 describes an X-ray imaging device including an X-ray generator and an X-ray imaging device. This X-ray imaging device takes an X-ray image of a subject by disposing the subject between the X-ray generator and the X-ray imaging device. Further, the X-ray imaging device described in Patent Document 1 includes an operation panel. The operation panel is disposed on the upper surface of the cover of the housing and includes buttons for controlling the rotation of the X-ray image displayed on the image display display. In the X-ray imaging device described in Patent Document 1, when the buttons disposed on the operation panel are operated, the X-ray image displayed on the image display display rotates.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, as with the X-ray imaging apparatus described in Patent Document 1 above, when rotating the X-ray image displayed on the image display (display unit) by operating buttons on the control panel during surgery or X-ray examination, the surgeon needs to move to the vicinity of the control panel and operate the buttons on the control panel. Operating such buttons during surgery or examination is cumbersome for the surgeon. In addition, although not described in Patent Document 1 above, there are cases where buttons on the control panel are operated to invert the X-ray image displayed on the display unit during surgery or examination. In this case as well, operating the button to invert the X-ray image is cumbersome for the surgeon. In these cases, when changing the orientation of the target area of ​​the subject in the X-ray image displayed on the display unit by rotating or inverting the X-ray image by operating buttons, operating the buttons is cumbersome for the surgeon. Therefore, it is desirable to reduce the effort required to change the orientation of the target area of ​​the subject in the X-ray image displayed on the display unit.

[0006] This invention was made to solve the above-mentioned problems, and one of its objectives is to provide an X-ray imaging system and an X-ray image display method that can reduce the effort required to change the orientation of the target area of ​​the subject in the X-ray image displayed on the display unit. [Means for solving the problem]

[0007] To achieve the above objective, the X-ray imaging system in the first aspect of this invention comprises an X-ray irradiation unit that irradiates a target area of ​​a subject with X-rays, an X-ray detection unit that detects X-rays irradiated from the X-ray irradiation unit and transmitted through the target area of ​​the subject, a display unit that displays an X-ray image generated based on the X-rays detected by the X-ray detection unit, and a control unit that causes the display unit to display the X-ray image. The control unit acquires a discrimination image of the target area of ​​the subject, determines the orientation of the target area in the acquired discrimination image, and, based on the determined orientation of the target area, performs at least one of the following processes: rotating the target area in the X-ray image displayed on the display unit so that it faces a predetermined display direction, and inverting the target area in the X-ray image displayed on the display unit, thereby changing the orientation of the target area of ​​the subject in the X-ray image displayed on the display unit. Note that "orientation of the target area" is described as a concept that includes both the direction of rotation of the target area in the image and the direction of inversion of the target area.

[0008] A second aspect of this invention relates to an X-ray image display method comprising the steps of: irradiating a target area of ​​a subject with X-rays; detecting the X-rays that have passed through the target area of ​​the subject; and displaying an X-ray image generated based on the detected X-rays on a display unit, wherein the step of displaying the X-ray image on the display unit includes: acquiring a discrimination image of the target area of ​​the subject; determining the orientation of the target area in the acquired discrimination image; and changing the orientation of the target area of ​​the subject in the X-ray image displayed on the display unit by performing at least one of the following: rotating the target area in the X-ray image displayed on the display unit so that it faces a predetermined display direction based on the determined orientation of the target area; and inverting the target area in the X-ray image displayed on the display unit. [Effects of the Invention]

[0009] The X-ray imaging system in the first aspect described above, and the X-ray image display method in the second aspect described above, as described above, determine the orientation of the target area in the acquired discrimination image, and based on the determined orientation of the target area, change the orientation of the target area in the X-ray image displayed on the display unit by performing at least one of the following processes: rotating the target area in the X-ray image displayed on the display unit so that it faces a predetermined display direction, and inverting the target area in the X-ray image displayed on the display unit. As a result, by determining the orientation of the target area in the discrimination image, the orientation of the target area in the X-ray image displayed on the display unit can be automatically changed without the need to operate buttons or other devices, even during surgery or examination. Consequently, the effort required to change the orientation of the target area in the X-ray image displayed on the display unit can be reduced. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram showing the overall configuration of the X-ray imaging system according to the first embodiment. [Figure 2] This is a block diagram showing the configuration of an X-ray imaging system according to the first embodiment. [Figure 3] This is a block diagram showing the functional configuration of the control unit. [Figure 4] This is a schematic diagram illustrating the imaging of a target area of ​​a subject using an X-ray machine. [Figure 5] This is a schematic diagram showing an example of an X-ray image where the orientation of the target area is tilted. [Figure 6] This is a flowchart illustrating the control process for the X-ray image display method according to the first embodiment. [Figure 7] This is a schematic diagram illustrating the shooting conditions, display direction, and storage of target shape information in the memory unit. [Figure 8] This is a flowchart illustrating the control process for displaying X-ray images in an X-ray image display method. [Figure 9] This is a diagram illustrating the determination of the orientation of the target part according to the first embodiment. [Figure 10] This is a diagram for explaining the change in the orientation of the target site. [Figure 11] This is a schematic diagram showing an example of the display of an X-ray image in which the orientation of the target site has been changed. [Figure 12] This is a schematic diagram showing the overall configuration of the X-ray imaging system according to the second embodiment. [Figure 13] This is a schematic diagram showing an example of an optical image. [Figure 14] This is a diagram for explaining the discrimination of the orientation of the target site according to the second embodiment. [Figure 15] This is a schematic diagram showing the overall configuration of the X-ray imaging system according to the third embodiment. [Figure 16] This is a diagram for explaining the discrimination of the orientation of the target site according to the third embodiment. [Figure 17] This is a diagram for explaining the inversion of an X-ray image.

Embodiments for Carrying Out the Invention

[0015] The X-ray irradiation unit 11 also includes an X-ray tube 11a as an X-ray source and a collimator 11b. The X-ray tube 11a irradiates X-rays when power is supplied to it. The X-ray tube 11a is heated by passing an electric current through its internal anode and cathode, and is configured to emit X-rays when thermionic electrons emitted from the cathode collide with the anode by applying a voltage between the anode and cathode. The X-rays generated in the X-ray tube 11a are configured to be irradiated toward the X-ray detection unit 12. The collimator 11b has a plurality of position-adjustable shielding plates (collimator leaves). The collimator 11b is configured to adjust the irradiation field of the X-rays irradiated from the X-ray tube 11a by shielding a portion of the X-rays from the X-ray tube 11a.

[0016] The X-ray detection unit 12 detects X-rays irradiated from the X-ray irradiation unit 11 that have passed through the target area 91 of the subject 90. The X-ray detection unit 12 has detection elements that detect X-rays from the X-ray irradiation unit 11 and is configured to output a detection signal indicating the intensity of the detected X-rays to the control unit 30. The X-ray detection unit 12 has a rectangular detection surface, on which a plurality of detection elements are arranged in a rectangular (grid) pattern. The X-ray detection unit 12 outputs a detection signal for generating a rectangular X-ray image 50. The X-ray detection unit 12 includes, for example, an image intensifier (II) or a flat panel detector (FPD).

[0017] The support section 13 integrally supports the X-ray irradiation section 11 and the X-ray detection section 12. The support section 13 is an arm member having an arc shape. The X-ray irradiation section 11 is positioned at one end of the support section 13, and the X-ray detection section 12 is positioned at the other end. The support section 13 is a so-called C-arm. The support section 13 positions the X-ray irradiation section 11 and the X-ray detection section 12 opposite each other, sandwiching the target area 91 of the patient 90 lying on the bed 103. The support section 13 is movably mounted to the trolley section 14. For example, the support section 13 is rotatably mounted to the trolley section 14. Alternatively, the support section 13 can be mounted vertically movably to the trolley section 14.

[0018] The trolley section 14 supports the support section 13. The trolley section 14 is equipped with a drive source, such as a motor, for moving the support section 13. The trolley section 14 also has wheels 14a and a handle 14b, and is configured to be movable. The trolley section 14 is moved when the handle 14b is held by an operator, such as a surgeon 95 (see Figure 4), and the wheels 14a rotate. The trolley section 14 may also have a drive source, such as a motor, for rotating the wheels 14a.

[0019] Furthermore, the trolley section 14 is equipped with an operation panel 15 and a touch panel 16. The operation panel 15 includes a plurality of operation buttons that receive input operations for controlling the operation of each part of the X-ray imaging apparatus 101. The touch panel 16 includes a pointing device that receives input operations for controlling the operation of each part of the X-ray imaging apparatus 101 and a display device such as a liquid crystal display. In the X-ray imaging apparatus 101, the operation panel 15 and the touch panel 16 constitute an operation unit that receives operations from an operator such as a surgeon 95 (see Figure 4). The operation panel 15 and the touch panel 16 output signals indicating the received input operations to the control unit 30. The operation panel 15 and the touch panel 16 receive operations that instruct, for example, setting the imaging conditions for X-rays irradiated by the X-ray irradiation unit 11, moving the support unit 13, starting X-ray irradiation, or changing the display on the display unit 20 and the touch panel 16. The touch panel 16 also displays the captured X-ray image 50 and information on the imaging conditions, including information such as the tube voltage and tube current applied to the X-ray tube 11a.

[0020] The display unit 20 displays an X-ray image 50 generated based on the X-rays detected by the X-ray detection unit 12. The display unit 20 is, for example, a monitor such as a liquid crystal display. The display unit 20 displays the captured X-ray image 50 and information on the X-ray exposure conditions. The display trolley 102 has a trolley section 21 that movably supports the display unit 20.

[0021] The control unit 30 controls X-ray imaging using the X-ray irradiation unit 11 and the X-ray detection unit 12. The control unit 30 also controls the generation of an X-ray image 50 based on the X-rays detected by the X-ray detection unit 12 by acquiring detection signals from the X-ray detection unit 12. The control unit 30 then controls the display of the generated X-ray image 50 on the touch panel 16 and the display unit 20. The control unit 30 is a computer including a processor (arithmetic unit) such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or an FPGA (Field-Programmable Gate Array) configured for image processing. Based on parameters and various programs that are pre-set and stored in the memory unit 40, the control unit 30 executes various control processes such as controlling X-ray imaging, controlling the generation of the X-ray image 50, and controlling the display of the X-ray image 50.

[0022] The memory unit 40 is, for example, a non-volatile memory such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The memory unit 40 stores pre-set X-ray imaging conditions for irradiating the target area 91 of the subject 90. The imaging conditions include, for example, information such as the tube voltage and tube current applied to the X-ray tube 11a, the pulse width of the irradiated X-rays, and the pulse rate. The memory unit 40 also stores multiple types of imaging conditions pre-set for each type of target area 91 of the subject 90. For example, the memory unit 40 has imaging conditions set for each type of target area 91, such as the head, chest, upper limbs, or lower limbs.

[0023] As shown in Figure 3, the control unit 30, which consists of a processor such as a CPU as hardware, includes a condition setting unit 31, an image capture control unit 32, a display processing unit 33, an image acquisition unit for discrimination 34, an orientation discrimination unit 35, and an orientation setting unit 36 ​​as functional blocks of software (programs). The control unit 30 functions as the condition setting unit 31, image capture control unit 32, display processing unit 33, image acquisition unit for discrimination 34, orientation discrimination unit 35, and orientation setting unit 36, respectively, when various programs stored in the storage unit 40 are executed by the processor. Note that the condition setting unit 31, image capture control unit 32, display processing unit 33, image acquisition unit for discrimination 34, orientation discrimination unit 35, and orientation setting unit 36 ​​may also be individually configured by hardware with dedicated processors (processing circuits).

[0024] In the first embodiment, as shown in Figure 4, the X-ray imaging device 101 performs X-ray imaging of the target area 91 of the subject 90 while a surgeon 95, such as a physician, performs the procedure (surgery). The surgeon 95 performs the procedure while visually recognizing the X-ray image 50 as a moving image displayed on the display unit 20. In this case, depending on the position of the treatment table 103 and the position of the surgeon 95, the X-ray imaging device 101 may be positioned at an angle to the target area 91 when X-ray imaging is performed. That is, the orientation in which the target area 91 is positioned may be inclined relative to the direction along each side of the rectangular detection surface of the X-ray detection unit 12.

[0025] In that case, as shown in Figure 5, the target area 91 of the subject 90 will be displayed in the X-ray image 50 shown on the display unit 20 at an angle, tilted from the horizontal or vertical direction along each side of the rectangular X-ray image 50. Therefore, the X-ray imaging system 100 of the first embodiment changes the orientation of the target area 91 in the X-ray image 50 shown on the display unit 20. Specifically, the control unit 30 performs a process to rotate the target area 91 in the X-ray image 50 shown on the display unit 20. The control unit 30 changes the orientation of the target area 91 in the X-ray image 50 without accepting an input operation to change the orientation.

[0026] (Control processing for X-ray image display method) Referring to Figures 6 to 11, the control process of the X-ray image display method according to the first embodiment will be described. In the X-ray image display method according to the first embodiment, the orientation of the target area 91 is changed in the X-ray image 50 displayed on the display unit 20. The control processes of steps S1 to S4 in the X-ray image display method, and the control processes of steps S11 to S15 included in step S4, are executed by the control unit 30.

[0027] As shown in Figure 6, first, in step S1, the shooting conditions are acquired. The condition setting unit 31 of the control unit 30 acquires the shooting conditions stored in the storage unit 40. For example, the condition setting unit 31 accepts the selection of shooting conditions based on input operations to the touch panel 16. For example, based on the acceptance of an operation to select the type of target area 91, the condition setting unit 31 acquires the shooting conditions corresponding to the selected type of target area 91 and sets the operation of the X-ray irradiation unit 11 so that X-rays corresponding to the acquired shooting conditions are irradiated.

[0028] Next, in step S2, X-rays are irradiated onto the target area 91 of the subject 90. The imaging control unit 32 of the control unit 30 irradiates the target area 91 with X-rays by controlling the operation of the X-ray irradiation unit 11 based on the imaging conditions acquired by the condition setting unit 31 in step S1. For example, the imaging control unit 32 starts irradiating with X-rays by the X-ray irradiation unit 11 based on an input operation to start X-ray irradiation.

[0029] Next, in step S3, X-rays that have passed through the target area 91 of the subject 90 are detected. The display processing unit 33 of the control unit 30 acquires a detection signal indicating the intensity of the X-rays detected by the X-ray detection unit 12.

[0030] Then, in step S4, the X-ray image 50 generated based on the detected X-rays is displayed on the display unit 20. The display processing unit 33 (control unit 30) generates the X-ray image 50 based on the detection signal acquired from the X-ray detection unit 12 and displays the generated X-ray image 50 on the display unit 20.

[0031] <Details of X-ray image display> In this first embodiment, in step S4, the display processing unit 33 (control unit 30) is configured to perform rotational image processing on the generated X-ray image 50, thereby rotating the target area 91 in the X-ray image 50 displayed on the display unit 20.

[0032] As shown in Figure 7, the memory unit 40 stores display direction information 60 as a predetermined display direction associated with each of the multiple imaging conditions. The memory unit 40 also stores target shape information 70 associated with each of the multiple imaging conditions. In other words, the display direction information 60 and the target shape information 70 are stored in association with the type of target area 91. The display direction information 60 is information indicating the display direction of the target area 91 in the X-ray image 50 displayed on the display unit 20. The display direction information 60 is information indicating a predetermined display direction, which is the orientation of the target area 91 displayed after a change (rotation) of the orientation of the target area 91 in the X-ray image 50. The target shape information 70 is set in accordance with the target area 91 and is information for determining the orientation of the target area 91. The target shape information 70 is information indicating the shape corresponding to the target area 91, for example, information indicating the shape corresponding to the shape of the bone portion of the target area 91.

[0033] In step S1 (see Figure 6), the condition setting unit 31 (control unit 30) acquires the selected shooting conditions and the display direction information 60 and target shape information 70 stored in association with the selected shooting conditions. For example, if the shooting conditions corresponding to the upper limb (arm) as the target area 91 are selected, the condition setting unit 31 sets the operation of the X-ray irradiation unit 11 so that X-rays corresponding to the selected shooting conditions are irradiated onto the arm. Then, by acquiring the display direction information 60 stored in association with the selected shooting conditions, the condition setting unit 31 sets the orientation of the arm in the X-ray image 50 displayed on the display unit 20. For example, based on the acquired display direction information 60, the condition setting unit 31 sets the display direction so that the arm is displayed horizontally and the wrist side faces left horizontally. The condition setting unit 31 also acquires information indicating the target shape information 70 stored in association with the selected shooting conditions. For example, if the target area 91 is the arm, the target shape information 70 is information indicating the shape of the radius 71 and ulna 72 (see Figure 9).

[0034] As shown in Figure 8, the control process for displaying the X-ray image 50 in step S4 includes the control processes in steps S11 to S15. In the first embodiment, the control processes in steps S11 to S15 are executed to change the orientation of the target area 91 in the X-ray image 50 based on the display direction information 60 and target shape information 70 acquired in step S1.

[0035] In step S11 (see Figure 8), a discrimination X-ray image 50 is acquired. The discrimination image acquisition unit 34 of the control unit 30 acquires a discrimination X-ray image 50 generated based on the X-rays detected by the X-ray detection unit 12 as a discrimination image of the target area 91 of the subject 90. That is, the discrimination image acquisition unit 34 acquires the X-ray image 50 generated by the display processing unit 33 as a discrimination image. For example, in the X-ray imaging system 100 of the first embodiment, the discrimination image acquisition unit 34 acquires a discrimination X-ray image 50 for determining the orientation of the target area 91 before generating the X-ray image 50 as a moving image.

[0036] Next, in step S12 (see Figure 8), the orientation of the target area 91 in the discrimination X-ray image 50 acquired as a discrimination image in step S11 is determined. The orientation determination unit 35 of the control unit 30 determines the orientation of the target area 91 in the X-ray image 50 by detecting the bone portion corresponding to the target area 91 in the X-ray image 50 acquired as a discrimination image. The orientation determination unit 35 determines the orientation of the target area 91 in the X-ray image 50 based on the target shape information 70 that is set in relation to the target area 91 and stored in the storage unit 40 in association with the shooting conditions.

[0037] For example, as shown in Figure 9, the orientation determination unit 35 (control unit 30) obtains orientation information 61 indicating the orientation of the target part 91 in the X-ray image 50 by comparing the target shape information 70 acquired in step S1 with the X-ray image 50 for determination. For example, if the target part 91 is an arm, the orientation determination unit 35 detects singularities (feature points) indicating bones in the X-ray image 50 by feature detection processing such as edge detection, and then detects the shape of the bones corresponding to the target shape information 70 in the X-ray image 50 by comparing the detected singularities with the shapes of the bones (radius 71 and ulna 72) shown in the target shape information 70 using image recognition such as pattern matching. Then, based on the comparison result with the target shape information 70, the orientation determination unit 35 obtains orientation information 61 as information indicating the angle in which the arm, which is the target part 91, is positioned in the X-ray image 50 for determination. The orientation determination unit 35 determines the orientation of the target part 91 by acquiring orientation information 61 that indicates an angle.

[0038] Next, in step S13 (see Figure 8), the rotation angle of the X-ray image 50 is set in order to change the orientation of the target area 91 in the X-ray image 50 displayed on the display unit 20. The orientation setting unit 36 ​​of the control unit 30 sets the rotation angle of the X-ray image 50 based on the orientation of the target area 91 determined in step S12.

[0039] As shown in Figure 10, the orientation setting unit 36 ​​(control unit 30) acquires rotation angle information 62, which indicates in which angular direction and by how much the X-ray image 50 should be rotated, based on the display direction set by the display direction information 60 in step S1 and the orientation information 61 acquired in step S12. The rotation angle information 62 is information indicating the magnitude of the angle by which the X-ray image 50 is rotated in order to orient the target area 91 in a predetermined display direction set by the display direction information 60. In other words, the rotation angle information 62 is information for setting a change in the orientation of the target area 91. For example, the rotation angle information 62 includes information such as "30 degrees clockwise". The orientation setting unit 36 ​​sets the rotation angle of the X-ray image 50 by storing the acquired rotation angle information 62 in the storage unit 40.

[0040] Next, in step S14 (see Figure 8), the orientation of the target area 91 in the X-ray image 50 displayed on the display unit 20 is changed. The display processing unit 33 of the control unit 30 rotates the target area 91 in the X-ray image 50 displayed on the display unit 20 by performing rotational image processing on the X-ray image 50 so that it faces a predetermined display direction that has been set in advance and stored in the storage unit 40 in association with the shooting conditions, based on the rotation angle set by the rotation angle information 62 acquired in step S13.

[0041] Next, in step S15 (see Figure 8), the modified X-ray image 50 is displayed on the display unit 20. As shown in Figure 11, after changing the orientation of the target area 91 in the X-ray image 50 displayed on the display unit 20 in step S14, the display processing unit 33 (control unit 30) displays the rotated X-ray image 50 on the display unit 20. Based on the rotation angle information 62 acquired in step S13, the display processing unit 33 causes the X-ray image 50, in which the orientation of the target area 91 has been changed by rotation in step S14, to be displayed on the display unit 20.

[0042] In this way, in step S4 (see Figure 8), based on the orientation of the target area 91 determined in step S12, a rotation angle is set in step S13, and rotational image processing is performed in step S14. As a result, the rotated X-ray image 50, based on the orientation of the determined target area 91, is displayed on the display unit 20 in step S15.

[0043] In the first embodiment, the display processing unit 33 of the control unit 30 rotates the X-ray image 50 for discrimination by performing rotational image processing on the X-ray image 50 based on the rotation angle set by the orientation setting unit 36, so that the target area 91 faces a predetermined display direction set by the display direction information 60. The display processing unit 33 then displays the rotated X-ray image 50 for discrimination on the display unit 20. In the X-ray imaging system 100, the rotation angle set by acquiring the X-ray image 50 for discrimination is stored in the storage unit 40. Furthermore, even when displaying the X-ray image 50 as a moving image after displaying the X-ray image 50 for discrimination, the display processing unit 33 (control unit 30) rotates the X-ray image 50 as a moving image based on the rotation angle set by acquiring the X-ray image 50 for discrimination, thereby rotating the target area 91 in the X-ray image 50 displayed on the display unit 20 as a moving image.

[0044] For example, in the X-ray imaging system 100, based on the imaging conditions set in step S1, the processes in steps S2 to S4 are repeated at a predetermined frame rate to generate and display an X-ray image 50 as a moving image. In this case, the control unit 30 first acquires an X-ray image 50 for discrimination using steps S2 to S4 to change the orientation of the target area 91 and sets the change in the orientation of the target area 91. Then, after setting the change in the orientation of the target area 91 using the X-ray image 50 for discrimination, the control unit 30 generates an X-ray image 50 and rotates the target area 91 to the set orientation, repeating this process at a predetermined frame rate to generate and display an X-ray image 50 as a moving image with the orientation of the target area 91 changed. In other words, when generating and displaying an X-ray image 50 as a moving image, the processes in steps S11 to S13 for setting the change in the orientation of the target area 91 in step S4 are omitted.

[0045] Furthermore, when displaying the X-ray image 50 as a moving image on the display unit 20 by continuously irradiating with X-rays, the orientation of the target area 91 may be determined and the X-ray image 50 rotated by acquiring the acquired X-ray image 50 as a discrimination image each time an X-ray image 50 is acquired. That is, each time the control processing of steps S2 to S4 is executed for each predetermined frame rate, the control processing of steps S11 to S15 may be executed in step S4. Also, when displaying the X-ray image 50 as a moving image on the display unit 20, the control processing of steps S11 to S13 may be executed at time intervals greater than the predetermined frame rate. That is, when displaying the X-ray image 50 as a moving image on the display unit 20, the orientation of the target area 91 may be set discretely at predetermined timings different from the predetermined frame rate.

[0046] [Second Embodiment] Next, a second embodiment of the present invention will be described with reference to Figures 12 to 14. In the second embodiment, unlike the first embodiment in which the orientation of the target area 91 was determined in the X-ray image 50, the orientation of the target area 91 is determined in an optical image 280 which is different from the X-ray image 50. Components identical to those in the first embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0047] As shown in Figure 12, the X-ray imaging system 200 according to the second embodiment includes an X-ray imaging apparatus 201. The X-ray imaging apparatus 201 includes an optical imaging unit 281 and an optical imaging unit 282. The optical imaging unit 281 and the optical imaging unit 282 are examples of the "irradiation unit side imaging unit" and the "detection unit side imaging unit" in the claims, respectively.

[0048] The optical imaging units 281 and 282 are, for example, optical cameras. The optical imaging units 281 and 282 have image sensors such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor. The optical imaging units 281 and 282 are arranged separately from each other. The optical imaging unit 281 is located in the X-ray irradiation unit 11. The optical imaging unit 282 is located in the X-ray detection unit 12. The optical imaging unit 281 is, for example, provided on the outer surface of the collimator 11b. The optical imaging unit 282 is, for example, provided on the outer surface of the X-ray detection unit 12. The optical imaging units 281 and 282 may be configured to detect not only visible light but also infrared light. If the optical imaging units 281 and 282 are configured to detect infrared light, the appearance of the subject 90 can be photographed by passing through a surgical drape or the like.

[0049] As shown in Figure 13, the optical imaging units 281 and 282 capture an optical image 280 of the subject 90. The optical image 280 is an image of the external appearance of the target area 91 of the subject 90. The optical imaging units 281 and 282 are arranged in an adjusted orientation so that the optical image 280 is captured in the same orientation as the X-ray image 50 generated based on the X-rays detected by the X-ray detection unit 12. For example, the optical imaging units 281 and 282 are arranged so that the direction in which the image sensors are aligned is aligned with the direction in which the detection elements of the X-ray detection unit 12 are aligned. The optical imaging units 281 and 282 output a signal indicating the captured optical image 280 to the control unit 30.

[0050] In the second embodiment, the control unit 30 acquires an optical image 280 captured by either the optical imaging unit 281 or the optical imaging unit 282 as a discrimination image for determining the orientation of the target area 91. Then, in the second embodiment, the control unit 30 determines the orientation of the target area 91 in the optical image 280 acquired as a discrimination image. In the second embodiment, the control unit 30 changes the orientation of the target area 91 of the subject 90 in the X-ray image 50 displayed on the display unit 20 by performing a process to rotate the target area 91 in the X-ray image 50 displayed on the display unit 20 based on the determined orientation of the target area 91 in the optical image 280.

[0051] As shown in Figure 14, specifically, the control unit 30 (condition setting unit 31) acquires target shape information 270 stored in the storage unit 40 in association with the shooting conditions, similar to the first embodiment. The target shape information 270 is set to correspond to the target part 91 of the subject 90, similar to the target shape information 70 of the first embodiment. In the second embodiment, the target shape information 270 is information indicating the external shape of the target part 91 of the subject 90. For example, if the target part 91 is the arm, the target shape information 270 is information indicating the external shape of the arm.

[0052] The control unit 30 (discrimination image acquisition unit 34) then acquires the optical image 280 as the discrimination image. Here, the X-ray imaging system 200 has two imaging units, an optical imaging unit 281 and an optical imaging unit 282. In X-ray imaging, there are two cases in which the X-ray irradiation unit 11 is positioned on the front side (above side) of the subject 90, and the X-ray irradiation unit 11 is positioned on the front side (above side) of the subject 90. The control unit 30 acquires the optical image 280 from the optical imaging unit 281 or optical imaging unit 282 that is positioned on the front side of the subject 90 as the discrimination image.

[0053] The control unit 30 (orientation determination unit 35) then determines the orientation of the target part 91 by acquiring orientation information 261 indicating the orientation of the target part 91 in the optical image 280, based on the target shape information 270 and the optical image 280. Similar to the first embodiment, the control unit 30 acquires orientation information 261 indicating the orientation of the target part 91 in the optical image 280 by comparing the target shape information 270 and the optical image 280. For example, the control unit 30 acquires orientation information 261 as information indicating the angle in which the target part 91 is positioned, by detecting the target part 91 from the optical image 280 using image recognition.

[0054] The process of rotating the X-ray image 50 based on the acquired orientation information 261 is the same as in the first embodiment. That is, the control unit 30 (orientation setting unit 36), as in the first embodiment, acquires rotation angle information 62 indicating which angular direction and by how much to rotate the X-ray image 50 based on the display direction set by the display direction information 60 and the acquired orientation information 261. Then, the control unit 30 (display processing unit 33), as in the first embodiment, changes (rotates) the orientation of the target area 91 in the X-ray image 50 displayed on the display unit 20 based on the acquired rotation angle information 62. The other configurations in the second embodiment are the same as in the first embodiment.

[0055] [Third Embodiment] Next, a third embodiment of the present invention will be described with reference to Figures 15 to 17. In the third embodiment, unlike the first and second embodiments which were configured to rotate the target area 91 in the X-ray image 50, the third embodiment is configured to invert the target area 391 in the X-ray image 350. Components identical to those in the first and second embodiments are denoted by the same reference numerals and their descriptions are omitted.

[0056] As shown in Figure 15, the X-ray imaging system 300 according to the third embodiment includes a ceiling-mounted X-ray irradiation unit 311, an X-ray detection unit 312 installed for performing X-ray imaging in a standing position, and a control unit 330. The X-ray irradiation unit 311 irradiates the target area 391 of the subject 90 with X-rays, similar to the X-ray irradiation unit 11 of the first embodiment. The X-ray detection unit 312 detects the X-rays that have passed through the target area 391, similar to the X-ray detection unit 12 of the first embodiment. In the third embodiment, the target area 391 is, for example, the chest of the subject 90. The configuration of the control unit 330 is the same as the control unit 30 of the first embodiment. Similar to the control unit 30 of the first embodiment, the control unit 330 controls X-ray imaging by the X-ray irradiation unit 311 and the X-ray detection unit 312, and displays the X-ray image 350 of the target area 391, which is the chest, on the display unit 20. Furthermore, the X-ray imaging system 300 of the third embodiment includes an optical imaging unit 383. The optical imaging unit 383 is located in the X-ray irradiation unit 311.

[0057] As shown in Figure 16, the optical imaging unit 383 captures an optical image 380 that includes the target area 391 of the subject 90. In the third embodiment, the control unit 330 acquires the optical image 380 as a discrimination image and determines the orientation of the target area 391 in the optical image 380. The orientation of the target area 391 here refers to whether it is the front side or the back side. The control unit 330 determines whether the front side or the back side of the target area 391, which is the chest of the subject 90, is captured in the optical image 380 by image recognition. Note that Figure 16 illustrates an example in which the back side of the subject 90 is captured.

[0058] As shown in Figure 17, in the third embodiment, the control unit 330 is configured to change the orientation of the target area 391 in the X-ray image 350 displayed on the display unit 20 by performing a process to invert the target area 391 in the X-ray image 350 displayed on the display unit 20 based on the orientation of the identified target area 391. For example, if the control unit 330 determines that the back side of the target area 391 of the subject 90 has been photographed in the optical image 380, it performs a left-right inversion image process on the X-ray image 350. The control unit 330 then displays the left-right inverted X-ray image 350 on the display unit 20. The other configurations in the third embodiment are the same as in the first embodiment.

[0059] [Differentiation] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than by the description of the embodiments above, and further includes all modifications (exceptions) within the meaning and scope equivalent to the claims. For example, instead of performing rotational image processing on the X-ray image, the X-ray detection unit may be rotated around a direction perpendicular to the detection surface based on the orientation of the identified target area, thereby rotating the target area in the X-ray image displayed on the display unit. Alternatively, the system may determine the orientation of the target area in the X-ray image rather than the optical image, thereby inverting the target area in the X-ray image displayed on the display unit. Alternatively, the system may perform a process to invert the target area in the X-ray image displayed on the display unit as a moving image. Furthermore, the display direction of the target area or the target shape information does not necessarily have to be stored in association with the shooting conditions (type of target area). The display direction or target shape information may be stored in the memory unit separately from the shooting conditions. Furthermore, in determining the orientation of the target area in the discrimination image, a pre-trained model generated by machine learning, such as deep learning, may be used. That is, the orientation of the target area included in the discrimination image may be determined by using a pre-trained model on the X-ray image or optical image acquired as the discrimination image. Furthermore, the orientation of the target area in the X-ray image may be determined by detecting shapes other than bone in the X-ray image acquired as a discriminatory image. For example, the orientation of the target area in the X-ray image may be determined by detecting body tissues such as blood vessels or internal organs. Furthermore, when arranging an optical imaging unit to capture optical images, the optical imaging unit may be placed only in the X-ray irradiation unit or the X-ray detection unit. Alternatively, the optical imaging unit may be placed in a location different from the X-ray irradiation unit and the X-ray detection unit. For example, the optical imaging unit may be placed in a support part such as a C-arm, or it may be placed in a location different from the X-ray imaging apparatus. Furthermore, when an optical imaging unit is provided to capture optical images, an optical imaging control unit (control board) that controls the operation of the optical imaging unit and generates optical images may be provided separately from the control unit that controls X-ray imaging. In this case, the optical imaging control unit that controls the operation of the optical imaging unit may acquire the optical image as a discrimination image, and the orientation of the target area in the optical image may be determined. Furthermore, the X-ray irradiation unit and the X-ray detection unit do not necessarily have to be integrally supported by a support unit. Furthermore, when an X-ray image is captured and displayed as a still image rather than a moving image, the orientation of the target area in the displayed X-ray image may be changed. Furthermore, the orientation of the target area in the displayed X-ray image may be changed not only during surgery, but also during examinations of the target area using X-ray imaging.

[0060] [Aspect] Those skilled in the art will understand that the exemplary embodiments described above are specific examples of the following embodiments.

[0061] (Item 1) An X-ray irradiation unit that irradiates the target area of ​​the subject with X-rays, An X-ray detection unit detects X-rays irradiated from the X-ray irradiation unit that have passed through the target area of ​​the subject, A display unit that displays an X-ray image generated based on the X-rays detected by the X-ray detection unit, The display unit comprises a control unit that causes the X-ray image to be displayed on the display unit, The control unit, A discrimination image is obtained in which the target area of ​​the subject is photographed. The orientation of the target part in the acquired discrimination image is determined, An X-ray imaging system that changes the orientation of a target area of ​​a subject in an X-ray image displayed on a display unit by performing at least one of the following processes: rotating the target area in the X-ray image displayed on the display unit so that it faces a predetermined display direction based on the orientation of the identified target area; and inverting the target area in the X-ray image displayed on the display unit. By determining the orientation of the target area in the discrimination image, the orientation of the target area of ​​the subject in the X-ray image displayed on the display unit can be automatically changed without the need to operate buttons or other devices during surgery or examination. As a result, the effort required to change the orientation of the target area of ​​the subject in the X-ray image displayed on the display unit can be reduced. (Item 2) The X-ray imaging system according to item 1, wherein the control unit performs rotational image processing on the generated X-ray image, or rotates the X-ray detection unit around a direction perpendicular to the detection surface, thereby rotating the target area in the X-ray image displayed on the display unit. By either performing rotational image processing on the X-ray image or rotating the X-ray detection unit, the target area in the displayed X-ray image can be easily rotated, thus easily reducing the effort required to change the orientation of the target area of ​​the subject in the X-ray image. Furthermore, when rotating the target area in the X-ray image by performing rotational image processing on the X-ray image, there is no need to arrange a configuration for rotating the X-ray detection unit, thus reducing the complexity of the X-ray imaging system. In addition, when rotating the target area in the X-ray image by rotating the X-ray detection unit, unlike when performing rotational image processing on the generated X-ray image, it is possible to suppress the cropping of the four corners of the X-ray image due to the rotational image processing. Therefore, it is possible to suppress a decrease in the visibility of the displayed X-ray image. (Item 3) The system further includes a storage unit for storing the imaging conditions for the X-rays irradiated onto the target area of ​​the subject, The storage unit stores the display direction of the target area in the X-ray image displayed on the display unit, in association with the shooting conditions. The X-ray imaging system according to item 1 or 2, wherein the control unit performs a process to rotate the target area in the X-ray image displayed on the display unit so that it faces the display direction which has been set in advance and stored in the memory unit in association with the imaging conditions. Since the display direction of the target area is stored in association with the imaging conditions, when performing X-ray imaging based on the stored imaging conditions, the display direction of the target area can be automatically set by setting the imaging conditions. Therefore, when rotating the target area in the X-ray image, the effort required to set the display direction can be reduced. As a result, the effort required to change the orientation of the target area of ​​the subject in the X-ray image displayed on the display unit can be further reduced. (Item 4) The system further includes a storage unit for storing the imaging conditions for the X-rays irradiated onto the target area of ​​the subject, The memory unit stores target shape information set to correspond to the target area, associated with the shooting conditions. The X-ray imaging system according to any one of items 1 to 3, wherein the control unit determines the orientation of the target area in the discrimination image based on the target shape information that is set in accordance with the target area and stored in the storage unit in association with the imaging conditions. Since the target shape information set for each target area is stored in association with the imaging conditions, when performing X-ray imaging based on the stored imaging conditions, the target shape information corresponding to the target area can be easily obtained by setting the imaging conditions. Therefore, even if the shape of the target area differs depending on the type of target area of ​​the subject, the corresponding target shape information can be easily obtained according to the type of target area, making it easy and accurate to determine the orientation of the target area in the discrimination image. (Item 5) The control unit, The X-ray image generated based on the X-rays detected by the X-ray detection unit is acquired as the discrimination image. The orientation of the target area in the X-ray image acquired as the discrimination image is determined, An X-ray imaging system according to any one of items 1 to 4, wherein, based on the orientation of the target area in the determined X-ray image, at least one of the processes of rotating and inverting the target area in the X-ray image displayed on the display unit. By acquiring the generated X-ray image as a discrimination image, unlike when a discrimination image is acquired separately from the X-ray image, it is not necessary to set up a new imaging unit or other configuration for acquiring the discrimination image, thus preventing the configuration of the X-ray imaging system from becoming overly complex. (Item 6) The X-ray imaging system according to item 5, wherein the control unit determines the orientation of the target area in the X-ray image by detecting the bone portion corresponding to the target area in the X-ray image acquired as the discrimination image. By detecting bone in X-ray images taken from inside the subject's body, the orientation of the target area in the X-ray image can be easily determined, even when the subject's appearance is covered by surgical drapes or clothing. (Item 7) The system further comprises an optical imaging unit for capturing optical images of the subject, The control unit, The optical image captured by the optical imaging unit is acquired as the discrimination image. The orientation of the target part in the optical image acquired as the discrimination image is determined, An X-ray imaging system according to any one of items 1 to 4, wherein, based on the orientation of the target area in the determined optical image, at least one of the processes of rotating and inverting the target area in the X-ray image displayed on the display unit. By acquiring optical images captured by the optical imaging unit as discrimination images, the orientation of the target area of ​​the subject can be determined without irradiating the subject with X-rays, unlike when X-ray images are acquired to determine the orientation of the target area. Therefore, it is possible to suppress an increase in the dose of X-rays irradiated to the subject. (Item 8) The X-ray imaging system according to item 7, wherein the optical imaging unit includes an irradiation unit-side imaging unit located in the X-ray irradiation unit and a detection unit-side imaging unit located separately from the irradiation unit-side imaging unit in the X-ray detection unit. Since the X-ray irradiation unit and the X-ray detection unit each have their own imaging units, the optical imaging unit can be suppressed from being obscured by instruments or other objects placed around the subject in the captured optical image, compared to the case where the optical imaging unit is located in only one of the X-ray irradiation unit or the X-ray detection unit. Therefore, it is possible to suppress a decrease in the accuracy of determining the orientation of the target area in the optical image. (Item 9) The system further includes a support portion that integrally supports the X-ray irradiation portion and the X-ray detection portion, The X-ray imaging system according to any one of items 1 to 8, wherein the control unit performs at least one of the processes of rotating and inverting the target area in the X-ray image generated based on the X-ray detected by the X-ray detection unit which is integrally supported with the X-ray irradiation unit by the support unit. Even when the X-ray irradiation unit and the X-ray detection unit are integrally supported by a support unit, the orientation of the target area of ​​the subject in the X-ray image displayed on the display unit can be automatically changed, effectively reducing the effort required to change the orientation of the target area of ​​the subject in the X-ray image displayed on the display unit. (Item 10) The X-ray irradiation unit is configured to continuously irradiate X-rays in order to capture the X-ray image as a moving image. The X-ray imaging system according to any one of items 1 to 9, wherein the control unit performs at least one of the following processes based on the orientation of the determined target area: rotating the target area in the X-ray image displayed on the display unit as a moving image, and inverting the target area in the X-ray image displayed on the display unit as a moving image. Even when displaying X-ray images as moving images on the display unit, the orientation of the target area of ​​the subject in the X-ray image can be automatically changed, effectively reducing the effort required to change the orientation of the target area of ​​the subject in the moving X-ray image displayed on the display unit. For example, when a procedure is performed on a subject while visually recognizing the X-ray image as a moving image, the orientation of the target area of ​​the subject in the X-ray image can be automatically changed without interrupting the procedure, thus more effectively reducing the effort required to change the orientation of the target area of ​​the subject. (Item 11) The steps include irradiating the target area of ​​the subject with X-rays, The steps include detecting X-rays that have passed through the target area of ​​the subject, The system includes the step of displaying an X-ray image generated based on the detected X-rays on a display unit, The step of displaying the X-ray image on the display unit is: The steps include: acquiring a discrimination image in which the target area of ​​the subject is photographed; A step of determining the orientation of the target part in the acquired discrimination image, An X-ray image display method comprising the steps of changing the orientation of the target area of ​​the subject in the X-ray image displayed on the display unit by performing at least one of the following: a process of rotating the target area in the X-ray image displayed on the display unit so that it faces a predetermined display direction based on the orientation of the determined target area; and a process of inverting the target area in the X-ray image displayed on the display unit. By determining the orientation of the target area in the discrimination image, the orientation of the target area of ​​the subject in the X-ray image displayed on the display unit can be automatically changed without the need to operate buttons or other devices, even during surgery or examination. As a result, an X-ray image display method can be provided that reduces the effort required to change the orientation of the target area of ​​the subject in the X-ray image displayed on the display unit. [Explanation of symbols]

[0062] 11, 311 X-ray irradiation section 12,312 X-ray detection unit 13 Support part 20 Display section 30, 330 Control Unit 40 Storage section 50, 350 X-ray images 70, 270 Target shape information 90 subjects 91,391 Target areas 100, 200, 300 X-ray imaging systems 280, 380 optical images 281 Optical imaging unit (Irradiation unit side imaging unit) 282 Optical imaging unit (detection unit side imaging unit) 383 Optical Imaging Section

Claims

1. An X-ray irradiation unit that irradiates the target area of ​​the subject with X-rays, An X-ray detection unit that detects X-rays irradiated from the X-ray irradiation unit and transmitted through the target area of ​​the subject, A display unit that displays an X-ray image generated based on the X-rays detected by the X-ray detection unit, The display unit comprises a control unit that causes the X-ray image to be displayed on the display unit, The control unit, A discrimination image is obtained in which the target area of ​​the subject is photographed. The orientation of the target part in the acquired discrimination image is determined, An X-ray imaging system that changes the orientation of a target area of ​​a subject in an X-ray image displayed on a display unit by performing at least one of the following processes: rotating the target area in the X-ray image displayed on the display unit so that it faces a predetermined display direction based on the orientation of the identified target area; and inverting the target area in the X-ray image displayed on the display unit.

2. The X-ray imaging system according to claim 1, wherein the control unit performs rotational image processing on the generated X-ray image, or rotates the X-ray detection unit around a direction perpendicular to the detection surface, thereby rotating the target area in the X-ray image displayed on the display unit.

3. The system further includes a storage unit that stores the imaging conditions for X-rays irradiated onto the target area of ​​the subject, The storage unit stores the display direction of the target area in the X-ray image displayed on the display unit, in association with the shooting conditions. The X-ray imaging system according to claim 1 or 2, wherein the control unit performs a process to rotate the target area in the X-ray image displayed on the display unit so that it faces the display direction which has been set in advance and stored in the memory unit in association with the imaging conditions.

4. The system further includes a storage unit that stores the imaging conditions for X-rays irradiated onto the target area of ​​the subject, The memory unit stores target shape information set to correspond to the target area, associated with the shooting conditions. The X-ray imaging system according to claim 1 or 2, wherein the control unit determines the orientation of the target area in the discrimination image based on the target shape information that is set in accordance with the target area and stored in the storage unit in association with the imaging conditions.

5. The control unit, The X-ray image generated based on the X-rays detected by the X-ray detection unit is acquired as the discrimination image. The orientation of the target area in the X-ray image acquired as the discrimination image is determined, The X-ray imaging system according to claim 1 or 2, wherein, based on the orientation of the target area in the determined X-ray image, at least one of the processes of rotating and inverting the target area in the X-ray image displayed on the display unit is performed.

6. The X-ray imaging system according to claim 5, wherein the control unit determines the orientation of the target area in the X-ray image by detecting the bone portion corresponding to the target area in the X-ray image acquired as the discrimination image.

7. The system further comprises an optical imaging unit for capturing optical images of the subject, The control unit, The optical image captured by the optical imaging unit is acquired as the discrimination image. The orientation of the target part in the optical image acquired as the discrimination image is determined, The X-ray imaging system according to claim 1 or 2, wherein, based on the orientation of the target area in the determined optical image, at least one of the processes of rotating and inverting the target area in the X-ray image displayed on the display unit is performed.

8. The X-ray imaging system according to claim 7, wherein the optical imaging unit includes an irradiation unit-side imaging unit located in the X-ray irradiation unit and a detection unit-side imaging unit located separately from the irradiation unit-side imaging unit in the X-ray detection unit.

9. The system further includes a support portion that integrally supports the X-ray irradiation portion and the X-ray detection portion. The X-ray imaging system according to claim 1 or 2, wherein the control unit performs at least one of the processes of rotating and inverting the target portion in the X-ray image generated based on the X-ray detected by the X-ray detection unit which is integrally supported with the X-ray irradiation unit by the support unit.

10. The X-ray irradiation unit is configured to continuously irradiate X-rays in order to capture the X-ray image as a moving image. The X-ray imaging system according to claim 1 or 2, wherein the control unit performs at least one of the following processes based on the orientation of the determined target area: rotating the target area in the X-ray image displayed on the display unit as a moving image, and inverting the target area in the X-ray image displayed on the display unit as a moving image.

11. The steps include irradiating the target area of ​​the subject with X-rays, The steps include detecting X-rays that have passed through the target area of ​​the subject, The system includes the step of displaying an X-ray image generated based on the detected X-rays on a display unit, The step of displaying the X-ray image on the display unit is: The steps include: acquiring a discrimination image in which the target area of ​​the subject is photographed; A step of determining the orientation of the target part in the acquired discrimination image, An X-ray image display method comprising the steps of changing the orientation of the target area of ​​the subject in the X-ray image displayed on the display unit by performing at least one of the following: a process of rotating the target area in the X-ray image displayed on the display unit so that it faces a predetermined display direction based on the orientation of the determined target area; and a process of inverting the target area in the X-ray image displayed on the display unit.

Images