X-ray imaging device

Abstract

The present invention provides an X-ray imaging apparatus that can prevent the operation from becoming complicated and the temporary interruption of patient observation caused by changing the output mode of the image signal in the X-ray detection unit in accordance with the movement of the X-ray irradiation range. [Solution] This X-ray imaging apparatus 100 comprises an X-ray irradiation unit 1, an X-ray detection unit 2 that outputs an image signal, a collimator 3, a control unit 6, and an image generation unit 4. The control unit 6 switches the output mode of the X-ray detection unit 2 to a first mode in which the time required to output the image signal is relatively long, but the visibility of the generated X-ray image 40 is relatively high, when the entire X-ray irradiation range 50 is included in the first region 20a. When at least a part of the X-ray irradiation range 50 is included in the second region 20b located outside the first region 20a, the control unit 6 switches the output mode of the X-ray detection unit 2 to a second mode in which the time required to output the image signal is relatively short, but the visibility of the generated X-ray image 40 is relatively low.

Description

Technical Field

[0001] The present invention relates to an X-ray imaging apparatus, and more particularly to an X-ray imaging apparatus that adjusts the irradiation range of X-rays in accordance with the movement of a region of interest in an X-ray image and performs imaging.

Background Art

[0002] Conventionally, an X-ray imaging apparatus that adjusts the irradiation range of X-rays in accordance with the movement of a region of interest in an X-ray image and performs imaging has been known (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses an X-ray diagnostic apparatus (X-ray imaging apparatus) including a top plate on which a subject is placed, an X-ray tube that irradiates X-rays, an X-ray detector that detects X-rays transmitted through the subject, and an aperture device that forms an irradiation range of X-rays on the X-ray detector. In the X-ray diagnostic apparatus disclosed in Patent Document 1, when the inspection target of the subject placed on the top plate is changed, if the changed inspection target is within the detection range of the X-ray detector, the aperture device is operated to move the center of the irradiation field. In the configuration disclosed in Patent Document 1, a configuration is disclosed in which the aperture device is operated to move the center of the irradiation field so that the center position of the irradiation field coincides with the changed inspection target. Further, in the configuration disclosed in Patent Document 1, when an endoscope is inserted into the body of the subject, moving the top plate imposes a large burden on the subject. Therefore, without moving the top plate, the aperture device is operated to move the center of the irradiation field.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Although not explicitly stated in Patent Document 1, when generating an X-ray image, depending on the positional relationship between the irradiation field (X-ray irradiation range) and the X-ray detector (X-ray detection unit), it may be difficult to generate an X-ray image with a predetermined level of visibility. Specifically, the X-ray image is generated based on the image signal output from the X-ray detection unit. Furthermore, the X-ray detection unit can detect X-rays only in the central region (first region). In the first region, the number of pixels is smaller than in the entire area of ​​the X-ray detection unit, so the time required to output the image signal is relatively longer, but it is possible to generate an X-ray image with relatively high visibility. However, in regions other than the first region (second region), due to the limitations of the X-ray detection unit, it is necessary to generate the X-ray image based on the image signal output from the entire area of ​​the X-ray detection unit. Therefore, it becomes difficult to generate an X-ray image with equivalent visibility compared to generating an X-ray image based on the image signal in the first region. As a countermeasure, it is conceivable to set the visibility when generating an X-ray image based on the image signal in the first region to a lower level, matching the visibility of the X-ray image based on the image signal in the second region. However, this is undesirable because it deliberately degrades the visibility of the X-ray image based on the image signal in the central region.

[0006] Therefore, it is conceivable to change the output mode of the image signal in the X-ray detection unit between the first and second regions. In this case, it is conceivable that the operator would set the output mode of the image signal in the X-ray detector in order to change the visibility of the X-ray image. However, if the operator sets the output mode of the image signal in the X-ray detector in order to change the visibility of the X-ray image, the operation becomes complicated and the observation of the subject is temporarily interrupted, which has the problem of reducing the operator's convenience (usability).

[0007] This invention was made to solve the above-mentioned problems, and one objective of this invention is to provide an X-ray imaging apparatus that can suppress the complicated operation and temporary interruption of patient observation caused by changing the output mode of the image signal in the X-ray detection unit in accordance with the movement of the X-ray irradiation range. [Means for solving the problem]

[0008] The X-ray imaging apparatus in the first aspect of this invention comprises an X-ray irradiation unit that irradiates X-rays, an X-ray detection unit having a facing surface opposite the X-ray irradiation unit and outputting an image signal based on the X-rays irradiated by the X-ray irradiation unit, an irradiation range changing unit that changes the position of the irradiation range of the X-rays irradiated from the X-ray irradiation unit on the facing surface, an image generation unit that generates an X-ray image based on the image signal output by the X-ray detection unit, a display unit that displays the X-ray image generated by the image generation unit, and a control unit, wherein the X-ray detection unit has a first region which is a predetermined area on the facing surface, and a first mode in which the time required to output the image signal in the predetermined area on the facing surface is relatively large, but the visibility of the X-ray image generated by the image generation unit is relatively high, and the position on the facing surface The output mode can be switched between a first mode, in which the time required to output an image signal within a fixed range is relatively small, but the visibility of the X-ray image generated by the image generation unit is relatively low. The control unit determines whether the X-ray irradiation range is in a first state, in which the entire X-ray irradiation range is included in the first region, or in a second state, in which at least a part of the X-ray irradiation range is included in the second region, which is located within the opposing surface but outside the first region, as a result of changing the position of the X-ray irradiation range on the opposing surface by the irradiation range changing unit. If it is determined that the state is the first state, the output mode of the X-ray detection unit is switched to the first mode. If it is determined that the state is the second state, the output mode of the X-ray detection unit is switched to the second mode.

[0009] Furthermore, the X-ray imaging apparatus in the second aspect of this invention comprises an X-ray irradiation unit that irradiates X-rays, an X-ray detection unit having a facing surface opposite the X-ray irradiation unit and outputting an image signal based on the X-rays irradiated by the X-ray irradiation unit, an irradiation range changing unit that changes the position of the irradiation range of the X-rays irradiated from the X-ray irradiation unit on the facing surface, an image generation unit that generates an X-ray image based on the image signal output by the X-ray detection unit, a display unit that displays the X-ray image generated by the image generation unit, and a control unit, wherein the X-ray detection unit has a first region which is a predetermined area on the facing surface, and although the time required to output the image signal in the predetermined area on the facing surface is relatively large, the visibility of the X-ray image generated by the image generation unit is relatively high. The output mode can be switched between a first mode and a second mode in which the time required to output the image signal within a predetermined range on the opposing surface is relatively short, but the visibility of the X-ray image generated by the image generation unit is relatively low. The control unit determines whether, as a result of changing the X-ray irradiation range by the irradiation range changing unit, the system is in a first state in which the entire X-ray irradiation range is included in the first region, or in a second state in which at least a part of the X-ray irradiation range is included in the second region, which is located within the opposing surface but outside the first region. If it is determined that the system is in the second state, the control unit deforms the X-ray irradiation range to maintain the first state and sets the output mode of the image signal in the X-ray detection unit to the first mode. [Effects of the Invention]

[0010] In the X-ray imaging apparatus described in the first phase above, the control unit determines whether the X-ray irradiation range is in a first state, where the entire X-ray irradiation range is included in the first region, or in a second state, where at least a part of the X-ray irradiation range is included in the second region, which is located within the opposing surface but outside the first region, as a result of the change made by the irradiation range changing unit on the opposing surface of the X-ray irradiation range. If it is determined to be in the first state, the control unit switches the output mode of the X-ray detection unit to the first mode. If it is determined to be in the second state, the control unit switches the output mode of the X-ray detection unit to the first mode. As a result, the system automatically switches between the first mode, which generates an X-ray image with relatively high visibility, and the second mode, which generates an X-ray image with relatively low visibility. Therefore, the operator can set an image signal output mode suitable for the positional relationship between the first region, the second region, and the X-ray irradiation range without having to change the image signal output mode of the X-ray detection unit. Consequently, it is possible to suppress the cumbersome operation and the temporary interruption of patient observation caused by changing the image signal output mode in the X-ray detection unit in response to the movement of the X-ray irradiation range.

[0011] Furthermore, in the X-ray imaging apparatus according to the second aspect described above, the control unit determines whether the X-ray irradiation range is in a first state, where the entire X-ray irradiation range is included in the first region, or in a second state, where at least a part of the X-ray irradiation range is included in the second region, which is located within the opposing surface but outside the first region, as a result of changing the position of the X-ray irradiation range on the opposing surface by the irradiation range changing unit. If it is determined that the state is the first state, the X-ray irradiation range is deformed to maintain the first state, and the output mode of the image signal in the X-ray detection unit is set to the first mode. Therefore, since the output mode of the image signal in the X-ray detection unit does not switch from the first mode, which generates a relatively highly visible X-ray image, due to the movement of the X-ray irradiation range, it is possible to suppress the complicated operation caused by changing the output mode of the image signal to the second mode in conjunction with the movement of the X-ray irradiation range, and to suppress the temporary interruption of the observation of the subject. Here, some operators may not need X-ray images of parts of the subject other than the part they wish to observe. Therefore, some operators may prefer that the X-ray imaging device be set to the first mode, which has relatively higher visibility of the generated X-ray image, rather than changing to the second mode, which has relatively lower visibility of the generated X-ray image, when the X-ray irradiation range moves to a position that spans both the first and second regions. Accordingly, in the X-ray imaging device described in the second aspect above, even if the control unit determines, as a result of the control of the irradiation range changing unit, that the X-ray irradiation range is in a second state in which at least a part of the X-ray irradiation range is included in the second region, the control unit deforms the X-ray irradiation range to maintain the first state and sets the output mode of the image signal in the X-ray detection unit to the first mode. This makes it possible to maintain the first mode, which has relatively higher visibility of the generated X-ray image, even when the X-ray irradiation range moves to a position that spans both the first and second regions. As a result, it is possible to provide an X-ray imaging device that can meet the needs of operators who desire that the device be set to the first mode, which has relatively higher visibility of the generated X-ray image, even when the X-ray irradiation range moves to a position that spans both the first and second regions. [Brief explanation of the drawing]

[0012] [Figure 1]This is a schematic diagram showing the overall configuration of an X-ray imaging apparatus according to the first embodiment. [Figure 2] This is a functional block diagram of an X-ray imaging apparatus according to the first embodiment. [Figure 3] This is a schematic diagram used to explain X-ray images. [Figure 4] This is a schematic diagram illustrating the first and second regions in the X-ray detection unit according to the first embodiment. [Figure 5] This is a schematic diagram illustrating the movement of the X-ray irradiation area on the opposing surface. [Figure 6] This is a schematic diagram illustrating the image signal output in the first mode. [Figure 7] This is a schematic diagram illustrating the image signal output in the second mode. [Figure 8] These are schematic diagrams (A) and (B) illustrating the configuration for adjusting the X-ray irradiation range using an irradiation range changing unit. [Figure 9] These are schematic diagrams (A) illustrating a configuration for generating X-ray images at a low frame rate and (B) illustrating a configuration for generating X-ray images at a high frame rate. [Figure 10] These are schematic diagrams (A) to (C) illustrating the differences in binning size in the X-ray detection unit. [Figure 11] This is a schematic diagram illustrating the output modes of image signals in the first and second modes, and a configuration for changing the preferred output mode of the image signal in the second mode. [Figure 12] This is a flowchart illustrating the process by which the control unit according to the first embodiment changes the output mode of the image signal. [Figure 13] This is a functional block diagram of an X-ray imaging apparatus according to the second embodiment. [Figure 14] This is a schematic diagram illustrating the configuration in which the control unit according to the second embodiment sets the irradiable area. [Figure 15] This is a schematic diagram illustrating the configuration of the control unit according to the second embodiment, which deforms the irradiable range. [Figure 16] It is a schematic diagram for explaining a configuration in which a control unit according to the second embodiment displays a frame line deformed in accordance with the irradiation range of the deformed X-ray. [Figure 17] It is a schematic diagram of an X-ray image generated by an image generation unit according to the second embodiment. [Figure 18] It is a flowchart for explaining a process in which a control unit according to the second embodiment modifies the irradiation range of an X-ray.

Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments embodying the present invention will be described based on the drawings.

[0014] [First Embodiment] (Configuration of X-ray Imaging Apparatus) Referring to FIGS. 1 to 12, the configuration of an X-ray imaging apparatus 100 according to the present embodiment will be described.

[0015] First, referring to FIGS. 1 and 2, the overall configuration of the X-ray imaging apparatus 100 will be described. As shown in FIGS. 1 and 2, the X-ray imaging apparatus 100 includes an X-ray irradiation unit 1, an X-ray detection unit 2, a collimator 3, an image generation unit 4, a display unit 5, a control unit 6, an input reception unit 7, a storage unit 8, and a top plate 9. The X-ray imaging apparatus 100 is configured to irradiate a subject with X-rays and acquire an X-ray image 40 (see FIG. 3). Note that the collimator 3 is an example of an "irradiation range changing unit" in the claims.

[0016] The X-ray irradiation unit 1 and the X-ray detection unit 2 are used to perform fluoroscopic imaging of a subject's imaging site placed on the top plate 9. Here, fluoroscopic imaging refers to a method of acquiring a moving image of an imaging site while irradiating X-rays with a lower dose than still image imaging.

[0017] The X-ray irradiation unit 1 is configured to irradiate X-rays. The X-ray irradiation unit 1 includes an X-ray tube that irradiates X-rays when power is supplied from a power supply device (not shown).

[0018] The X-ray detection unit 2 has a facing surface 20 (see Figure 4) that faces the X-ray irradiation unit 1. The X-ray detection unit 2 also has a plurality of pixels 2a (see Figure 10(A)) that are provided below the facing surface 20 and accumulate charge. The X-ray detection unit 2 is, for example, an FPD (flat panel detector). The X-ray detection unit 2 is configured to output an image signal based on the X-rays irradiated by the X-ray irradiation unit 1.

[0019] In the X-ray imaging apparatus 100, the X-ray irradiation unit 1 is provided on the front side of the top plate 9, and the X-ray detection unit 2 is provided on the back side of the top plate 9. The X-ray irradiation unit 1 and the X-ray detection unit 2 are provided facing each other with the top plate 9 in between.

[0020] The collimator 3 is configured to change its position on the opposite surface 20 of the X-ray irradiation range 50 (see Figure 5) irradiated from the X-ray irradiation unit 1. The collimator 3 is positioned in front of the X-ray emission direction. Inside the collimator 3 are a first group of multiple shielding vanes 130 provided on the X-ray tube side, as shown in Figure 8(A), and a second group of multiple shielding vanes 140 provided on the top plate 9 side, as shown in Figure 8(B). The X-rays irradiated from the X-ray tube pass through the opening 3a (X-ray irradiation range 50) formed by the first group of multiple shielding vanes 130 and the second group of multiple shielding vanes 140. Details of how the collimator 3 adjusts the opening 3a (X-ray irradiation range 50) with the first group of multiple shielding vanes 130 and the second group of multiple shielding vanes 140 will be described later.

[0021] The image generation unit 4 is configured to generate an X-ray image 40 based on the image signal output by the X-ray detection unit 2. In this embodiment, the image generation unit 4 generates the X-ray image 40 as a moving image. The image generation unit 4 includes a GPU (Graphics Processing Unit) or an FPGA (Field-Programmable Gate Array) configured for image processing.

[0022] The display unit 5 is configured to display multiple X-ray images 40 generated by the image generation unit 4. The display unit 5 includes, for example, a liquid crystal monitor, an organic EL (Electro-Luminescence) monitor, and other display devices.

[0023] The control unit 6 is configured to control the collimator 3 and the output mode of the image signal in the X-ray detection unit 2. The control unit 6 includes a processor or circuit, such as a CPU (Central Processing Unit), and memory, such as ROM (Read Only Memory) or RAM (Random Access Memory).

[0024] The input receiving unit 7 is configured to receive operation input from the operator. The input receiving unit 7 includes, for example, a keyboard and a pointing device such as a mouse. The display unit 5 and the input receiving unit 7 may be integrally formed as a touch panel.

[0025] The memory unit 8 stores various programs executed by the control unit 6. The memory unit 8 also stores first mode information 30 and second mode information 31. The first mode information 30 and second mode information 31 are the conditions for the modes in which the X-ray detection unit 2 outputs an image signal. Details of the conditions for the modes in which the X-ray detection unit 2 outputs an image signal will be described later.

[0026] The top plate 9 is configured to support the subject. The top plate 9 has a support surface 9a on which the subject is placed. In this specification, the X direction is the longitudinal direction of the top plate 9 when it is in a horizontal position. The Y direction is the short direction of the top plate 9 when it is in a horizontal position. The Z direction is the vertical direction.

[0027] The X-ray imaging apparatus 100 includes a base 10, a first support column 11, a holding section 12, and a second support column 13 as its support mechanism. Furthermore, as shown in Figure 2, the X-ray imaging apparatus 100 includes a holding section moving mechanism 14, a top plate moving mechanism 15, an X-ray detection section moving mechanism 16, and an X-ray irradiation section moving mechanism 17 as its movement mechanism. Additionally, the X-ray imaging apparatus 100 includes a top plate rotating mechanism 18 and an X-ray irradiation section rotating mechanism 19 as its rotation mechanism.

[0028] Furthermore, as shown in Figure 1, the first support column 11 supports the entire X-ray imaging apparatus 100. The first support column 11 is mounted on the base 10. The first support column 11 is provided with a holding part movement mechanism 14 (see Figure 2). The holding part movement mechanism 14 allows the holding part 12 to move in the Z direction.

[0029] The holding unit 12 holds the top plate 9, the second support column 13, and the X-ray detection unit 2. The holding unit 12 is equipped with a top plate moving mechanism 15 (see Figure 2), an X-ray detection unit moving mechanism 16 (see Figure 2), and a top plate rotation mechanism 18 (see Figure 4). The top plate moving mechanism 15 allows the top plate 9 to move in the direction of its shorter side (Y direction in Figure 1). The X-ray detection unit moving mechanism 16 allows the X-ray detection unit 2 to move in the direction of its longer side (X direction in Figure 2) on the top plate 9. Note that the XY direction in Figure 2 is approximately horizontal. The top plate rotation mechanism 18 allows the top plate 9 to rotate around an axis 90 that extends along the direction of its shorter side (Y direction).

[0030] The second support column 13 supports the X-ray irradiation unit 1. The second support column 13 is provided with an X-ray irradiation unit moving mechanism 17 (see Figure 4) and an X-ray irradiation unit rotation mechanism 19 (see Figure 2). The X-ray irradiation unit moving mechanism 17 allows the X-ray irradiation unit 1 to move in the longitudinal direction (X direction in Figure 2) on the top plate 9. The X-ray irradiation unit 1 and the X-ray detection unit 2 can move integrally with respect to the top plate 9 by the synchronous operation of the X-ray irradiation unit moving mechanism 17 and the X-ray detection unit moving mechanism 16. The X-ray irradiation unit rotation mechanism 19 allows the X-ray irradiation unit 1 to rotate around an axis 91 extending along the short direction (Y direction) of the top plate 9.

[0031] (X-ray image) Figure 3 is a schematic diagram of the X-ray image 40. As shown in Figure 3, the X-ray image 40 shows bone 70 and devices 71, etc. Devices 71 include, for example, catheters or endoscopes. In addition, a region of interest 51 is superimposed on the X-ray image 40. The region of interest 51 is the area that the operator wants to examine.

[0032] In the first embodiment, the control unit 6 (see Figure 2) is configured to control the movement of the region of interest 51 in the X-ray image 40. Specifically, when an operation input to move the region of interest 51 is received via the input receiving unit 7 (see Figure 2), the control unit 6 moves the region of interest 51 in accordance with the operation input. Furthermore, if the region of interest 51 is set at the tip of a device 71, the control unit 6 may recognize the tip of the device 71 and move the region of interest 51 to match the position of the tip of the device 71.

[0033] (Second and Second Domains) Figure 4 shows the opposing surface 20 of the X-ray detection unit 2. The opposing surface 20 includes at least a first region 20a and a second region 20b. The first region 20a is a predetermined region on the opposing surface 20. The second region 20b is the region of the opposing surface 20 outside of the first region 20a.

[0034] (Movement of irradiation area) In the first embodiment, the control unit 6 (see Figure 2) is configured to control the movement of the X-ray irradiation range 50 based on the movement of the region of interest 51 (see Figure 3). For example, as shown in Figure 5, the control unit 6 moves the X-ray irradiation range 50a, which is located in the first region 20a and adjusted to be smaller in size (area) than the first region 20a, to a position that spans the first region 20a and the second region 20b, as indicated by arrow 80a. Also, as indicated by arrow 80b, the control unit 6 moves the X-ray irradiation range 50b, which is positioned to span the first region 20a and the second region 20b, into the first region 20a. The control unit 6 moves the X-ray irradiation range 50 without moving the top plate 9 (see Figure 1) by controlling the collimator 3 (see Figure 2).

[0035] When the X-ray irradiation area 50a is located in the first region 20a, the X-ray detection unit 2 outputs an image signal from the first region 20a. Furthermore, X-rays are irradiated only within the X-ray irradiation area 50a of the first region 20a. Therefore, as shown in Figure 6, the image signal within the X-ray irradiation area 50a of the first region 20a has pixel values ​​corresponding to the body part of the subject. Thus, the area within the X-ray irradiation area 50a is imaged. In addition, there is no image signal in the area of ​​the first region 20a other than the X-ray irradiation area 50a because X-rays are not irradiated there. Therefore, the X-ray image 40 is displayed as a black-filled area.

[0036] When the X-ray irradiation area 50a is positioned to span the first region 20a and the second region 20b, the X-ray detection unit 2 outputs an image signal from the entire opposing surface 20 (the first region 20a and the second region 20b). Furthermore, X-rays are irradiated only within the X-ray irradiation area 50a of the opposing surface 20. Therefore, as shown in Figure 7, the image signal within the X-ray irradiation area 50a of the opposing surface 20 has pixel values ​​corresponding to the body part of the subject. Consequently, the area within the X-ray irradiation area 50a is imaged. In addition, there is no image signal in the area of ​​the opposing surface 20 other than the X-ray irradiation area 50a because X-rays are not irradiated there. Therefore, the X-ray image 40 is displayed as a black-filled area.

[0037] (Changing the X-ray irradiation range using a collimator) As shown in Figure 8(A), the first group of shielding vanes 130 includes a first shielding vane 131, a second shielding vane 132, a third shielding vane 133, and a fourth shielding vane 134. The first shielding vane 131 is located on the Y1 side inside the collimator 3 and is configured to focus the irradiated X-rays by moving in the Y2 direction. The second shielding vane 132 is located on the Y2 side inside the collimator 3 and is configured to focus the irradiated X-rays by moving in the Y1 direction. The third shielding vane 133 is located on the X1 side inside the collimator 3 and is configured to focus the irradiated X-rays by moving in the X2 direction. The fourth shielding vane 134 is located on the X2 side inside the collimator 3 and is configured to focus the irradiated X-rays by moving in the X1 direction.

[0038] The first shielding vane 131, the second shielding vane 132, the third shielding vane 133, and the fourth shielding vane 134 are configured to move independently of each other. Each of the first shielding vane 131, the second shielding vane 132, the third shielding vane 133, and the fourth shielding vane 134 is configured to move in response to an operation input to the input receiving unit 7 (see Figure 2).

[0039] As shown in Figure 8(B), the second group of shielding vanes 140 includes a fifth shielding vane 141, a sixth shielding vane 142, a seventh shielding vane 143, and an eighth shielding vane 144. The fifth shielding vane 141 is located on the Y1 side inside the collimator 3 and is configured to focus the irradiated X-rays by moving in the Y2 direction. The sixth shielding vane 142 is located on the Y2 side inside the collimator 3 and is configured to focus the irradiated X-rays by moving in the Y1 direction. The fifth shielding vane 141 and the sixth shielding vane 142 are configured as a first pair of shielding vanes 140a that are symmetrically controlled to move closer to or further away from each other along the Y direction.

[0040] The seventh shielding vane 143 is located inside the collimator 3 on the X1 side and is configured to focus the irradiated X-rays by moving in the X2 direction. The eighth shielding vane 144 is located inside the collimator 3 on the X2 side and is configured to focus the irradiated X-rays by moving in the X1 direction. The seventh shielding vane 143 and the eighth shielding vane 144 are configured as a second pair of shielding vanes 140b that are symmetrically controlled to move closer to or further away from each other along the X direction.

[0041] The first pair of shielding vanes 140a, consisting of the fifth shielding vane 141 and the sixth shielding vane 142, and the second pair of shielding vanes 140b, consisting of the seventh shielding vane 143 and the eighth shielding vane 144, are each configured to be movable in response to operational inputs to the input receiving unit 7 (see Figure 2).

[0042] Specifically, the multiple shielding vanes 130 of the first group are configured to individually adjust the position of each side of the X-ray irradiation area 50. The multiple shielding vanes 140 of the second group are configured to adjust the width (left-right dimension) and length (up-down dimension) of the X-ray irradiation area 50 without changing the central position of the X-ray irradiation area 50. Based on the set region of interest 51, the control unit 6 sets the X-ray irradiation area 50 and irradiates X-rays from the X-ray irradiation unit 1 to capture an X-ray image 40 of the region of interest 51.

[0043] Here, the X-ray detection unit 2 outputs an image signal based on the X-rays irradiated by the X-ray irradiation unit 1 onto the opposing surface 20 (see Figure 4). The image generation unit 4 (see Figure 2) generates an X-ray image 40 based on the image signal output by the X-ray detection unit 2. In the first embodiment, since the image generation unit 4 generates the X-ray image 40 as a moving image, the visibility of the X-ray image 40 is determined by at least one of the frame rate (number of frames per unit time) and the resolution.

[0044] Graph 60a shown in Figure 9(A) is a graph of the case when the frame rate is low when generating the X-ray image 40 as a moving image (see Figure 3). The horizontal axis of graph 60a is time. As shown in graph 60a, when the image generation unit 4 (see Figure 2) generates the X-ray image 40 as a moving image, it repeats a data storage period 61a and a data reading period 61b. The frame rate of the moving image is determined by the sum of the time of one data storage period 61a and one data reading period 61b. That is, the frame rate is determined by the sum of the time from time t0 to time t1 62a and the time from time t1 to time t2 62b. The data storage period 61a is the period during which charge is accumulated in multiple pixels 2a of the X-ray detection unit 2. The data reading period 61b is the period during which the charge accumulated in multiple pixels 2a of the X-ray detection unit 2 is read out.

[0045] Graph 60b shown in Figure 9(B) is a graph of the case when the frame rate is high when generating the X-ray image 40 as a moving image (see Figure 3). In graph 60b, the horizontal axis is time. The data storage period 61c and data reading period 61d in graph 60b are shorter than the data storage period 61a and data reading period 61b in graph 60a. That is, in graph 60b, the sum of the time from time t0 to time t1 (62c) and the time from time t1 to time t2 (62d) is shorter than the sum of the time from time t0 to time t1 (62a) and the time from time t1 to time t2 (62b) in graph 60a. Therefore, the X-ray image 40 generated under the conditions of data storage period 61c and data reading period 61d shown in graph 60b has a higher frame rate than the X-ray image 40 generated under the conditions of data storage period 61a and data reading period 61b shown in graph 60a. The data storage period 61c is the period during which charge is accumulated in multiple pixels 2a of the X-ray detection unit 2. The data reading period 61d is the period during which the charge accumulated in the multiple pixels 2a of the X-ray detection unit 2 is read out.

[0046] Figure 10 shows a configuration for changing the number of pixels that output an image signal from the X-ray detection unit 2. Specifically, the X-ray detection unit 2 is configured to change the number of pixels that output an image signal by hardware binning.

[0047] Figure 10 shows examples of three different binning sizes. Figure 10(A) shows the case where the binning size is "small," Figure 10(B) shows the case where the binning size is "medium," and Figure 10(C) shows the case where the binning size is "large." In Figure 10(A), each pixel 2a included in the X-ray detection unit 2 outputs an image signal. In Figure 10(B), four pixels 2a in a 2x2 arrangement are treated as one pixel 2b and an image signal is output. In Figure 10(C), nine pixels 2a in a 3x3 arrangement are treated as one pixel 2c and an image signal is output. Therefore, as the binning size increases, the number of pixels outputting an image signal decreases, thus shortening the time required to output the image signal. However, as the number of pixels outputting an image signal decreases as the binning size increases, the resolution of the X-ray image 40 decreases.

[0048] The first region 20a (see Figure 4), which is the central part of the opposing surface 20 (see Figure 4), has fewer pixels compared to the entire opposing surface 20. Therefore, even if the binning size is reduced to improve the visibility of the X-ray image 40, increasing the time required to output the image signal, a high frame rate can be maintained. As a result, when generating an X-ray image 40 (see Figure 3) as a moving image based on X-rays detected only in the first region 20a, an X-ray image 40 with relatively high visibility (at a predetermined frame rate and resolution) can be generated. However, if at least a part of the X-ray irradiation range 50 (see Figure 5) is located in the second region 20b (see Figure 4), which is outside the first region 20a of the opposing surface 20, it is necessary to output the image signal from all pixels 2a of the opposing surface 20 due to the limitations of the X-ray detection unit 2. Therefore, when the X-ray irradiation area 50 is located in the second region 20b, the number of pixels 2a that output the image signal increases, which may make it difficult to generate an X-ray image 40 with the same visibility as an X-ray image 40 generated based on X-rays detected only in the first region 20a.

[0049] Therefore, in the first embodiment, the control unit 6 determines whether the X-ray irradiation range 50 is in a first state, where the entire X-ray irradiation range is included in the first region 20a, or in a second state, where at least a part of the X-ray irradiation range 50 is within the opposing surface 20 and is included in the second region 20b, which is located outside the first region 20a, as a result of the position change of the X-ray irradiation range 50 on the opposing surface 20 by the collimator 3. If the control unit 6 determines that the X-ray irradiation range 50 is in the first state, it switches the output mode of the X-ray detection unit 2 to the first mode. If the control unit 6 determines that the X-ray irradiation range 50 is in the second state, it switches the output mode of the X-ray detection unit 2 to the second mode.

[0050] In the first embodiment, when the control unit 6 outputs an image signal from the X-ray detection unit 2 in the first mode, it generates an X-ray image 40 with relatively high visibility based on a predetermined frame rate and a predetermined resolution. The predetermined frame rate is, for example, 30 fps (frames per second). The predetermined resolution is, for example, either a "small" binning size in which the image signal is output directly from each pixel 2a of the X-ray detection unit 2, or a "medium" binning size in which four pixels 2a in a 2x2 arrangement of multiple pixels 2a of the X-ray detection unit 2 are treated as one pixel 2b and the image signal is output.

[0051] Furthermore, the control unit 6 is configured to either lower the frame rate of the X-ray image 40 or lower the resolution of the X-ray image 40 when the visibility of the X-ray image 40 generated based on the image signal output in the second mode is lower than the visibility of the X-ray image 40 generated based on the image signal output in the first mode. When lowering the frame rate of the X-ray image 40 in the second mode, for example, the control unit 6 sets the frame rate of the generated X-ray image 40 to 15 fps. Also, when lowering the resolution of multiple X-ray images 40 generated based on the image signal output in the second mode, the control unit 6 sets the binning size to be larger than the binning size in the first mode. For example, if the binning size in the first mode is "small", the control unit 6 sets the binning size to "medium" in the second mode. Furthermore, if the binning size in the first mode is "medium", the control unit 6 sets the binning size in the second mode to "large", treating 3x3 (9 pixels 2a) of the multiple pixels 2a of the X-ray detection unit 2 as one pixel 2c and outputting an image signal.

[0052] In the first embodiment, the control unit 6 stores the frame rate and resolution of the X-ray image 40 generated based on the image signal output in the first mode as first mode information 30 (see Figure 2) in the storage unit 8 (see Figure 2). The control unit 6 also stores the frame rate and resolution of the X-ray image 40 generated based on the image signal output in the second mode as second mode information 31 (see Figure 2) in the storage unit 8.

[0053] In the first embodiment, when the image generation unit 4 generates an X-ray image 40 based on the image signal output in the first mode, it generates an X-ray image 40 with a higher frame rate and resolution than the X-ray image 40 generated based on the image signal output in the second mode. That is, the X-ray image 40 generated based on the image signal output in the first mode is relatively more visible than the X-ray image 40 generated based on the image signal output in the second mode. Also in the first embodiment, the control unit 6 displays the generated X-ray image 40 on the display unit 5.

[0054] (Setting the readout conditions for the charge accumulated in multiple pixels of the X-ray detection unit) Here, if the output mode of the image signal output from the X-ray detection unit 2 is switched to either the first mode or the second mode based on the operator's input, the operator's operation becomes complicated. Also, if the mode switching operation is performed in the middle of an examination using device 71 (see Figure 3), the operator will have to take their eyes off device 71, and the examination will be temporarily interrupted.

[0055] Therefore, in the first embodiment, the control unit 6 determines whether the X-ray irradiation range 50 is in a first state, where the entire X-ray irradiation range 50 is included in the first region 20a, or in a second state, where at least a part of the X-ray irradiation range 50 is within the opposing surface 20 but outside the first region 20a, as a result of the position change of the X-ray irradiation range 50 on the opposing surface 20 by the collimator 3. If the control unit 6 determines that the X-ray irradiation range 50 is in the first state, it switches the output mode of the X-ray detection unit 2 to the first mode. If the control unit 6 determines that the X-ray irradiation range 50 is in the second state, it switches the output mode of the X-ray detection unit 2 to the second mode.

[0056] Here, when generating an X-ray image 40 based on the image signal output in the second mode, the choice of whether to lower the frame rate or the resolution depends on the operator's preference. That is, some operators prefer to maintain the frame rate even if it reduces the resolution, while others prefer to maintain the resolution even if it reduces the frame rate. Therefore, in the first embodiment, as shown in Figure 11, the control unit 6 (see Figure 2) is configured to set, based on the input input received via the input receiving unit 7 (see Figure 2), whether to lower the frame rate of the X-ray image 40 or lower the resolution of the X-ray image 40 when the visibility of the X-ray image 40 (see Figure 3) generated based on the image signal output in the second mode is lower than the visibility of the X-ray image 40 generated based on the image signal output in the first mode.

[0057] Table 63 in Figure 11 shows the conditions for lowering the resolution when the visibility of the X-ray image 40 generated based on the image signal output in the second mode is lower than the visibility of the X-ray image 40 generated based on the image signal output in the first mode. Table 64 shows the conditions for lowering the frame rate when the visibility of the X-ray image 40 generated based on the image signal output in the second mode is lower than the visibility of the X-ray image 40 generated based on the image signal output in the first mode. As shown in Tables 63 and 64, the X-ray image 40 generated in the first mode has relatively higher visibility than the X-ray image 40 generated in the second mode by increasing both the frame rate and resolution of the generated X-ray image 40. A higher frame rate means a higher frame rate compared to the X-ray image 40 generated based on the image signal output in the second mode. For example, if the frame rate of the multiple X-ray images 40 generated based on the image signal output in the second mode shown in Table 64 is 7.5 fps, then the frame rate will be considered high even if the frame rate of the X-ray image 40 generated based on the image signal output in the first mode is 15 fps. Similarly, regarding the resolution shown in Table 63, if the resolution of the X-ray image 40 generated based on the image signal output in the first mode is higher than the resolution of the X-ray image 40 generated based on the image signal output in the first mode, then the frame rate will be considered high regardless of the numerical resolution.

[0058] The control unit 6 updates the second mode information 31 stored in the memory unit 8 based on the output conditions of the image signal in the second mode, which are set based on the operation input. In other words, the control unit 6 overwrites the second mode information 31 stored in the memory unit 8 with the frame rate and resolution in the second mode, which are set based on the operation input.

[0059] When storing the first mode information 30 and the second mode information 31, the number (No.) is associated with the frame rate and resolution. Therefore, when the control unit 6 switches between the first mode and the second mode, it switches the output mode based on the number. Alternatively, the control unit 6 may switch between the first mode and the second mode by setting the frame rate and resolution separately, rather than by the number.

[0060] (Image signal output mode change processing) Next, referring to Figure 12, we will explain the process by which the control unit 6 (see Figure 2) changes the mode in which it outputs an image signal from the X-ray detection unit 2 (see Figure 2).

[0061] In step 101, the control unit 6 determines whether or not to move the region of interest 51 (see Figure 3). If the region of interest 51 is to be moved, the process proceeds to step 102. If the region of interest 51 is not to be moved, the process proceeds to step 107.

[0062] If the process proceeds from step 101 to step 102, in step 102, the control unit 6 moves the region of interest 51.

[0063] Next, in step 103, the control unit 6 determines whether the entirety of the moved region of interest 51 is located within the first region 20a (see Figure 4) of the opposing surface 20 (see Figure 4) of the X-ray detection unit 2 (see Figure 4). If the moved region of interest 51 is located within the first region 20a, the process proceeds to step 104. If the moved region of interest 51 is not located within the first region 20a, the process proceeds to step 105.

[0064] If the process proceeds from step 103 to step 104, in step 104, the control unit 6 switches the mode in which the X-ray detection unit 2 outputs the image signal to the first mode. If the image signal output mode is already set to the first mode, the process in step 104 is skipped.

[0065] Furthermore, if the process proceeds from step 103 to step 105, in step 105, the control unit 6 switches the mode in which the X-ray detection unit 2 outputs the image signal to the second mode. If the image signal output mode is already set to the second mode, the process in step 105 is skipped.

[0066] Next, in step 106, the control unit 6 moves the X-ray irradiation range 50. Specifically, the control unit 6 moves the X-ray irradiation range 50 by controlling the collimator 3 (see Figure 8). Note that the process in step 106 may be performed after step 102.

[0067] Next, in step 107, the control unit 6 generates an X-ray image 40 by controlling the X-ray irradiation unit 1 (see Figure 2), the X-ray detection unit 2, the collimator 3, and the image generation unit 4 (see Figure 2).

[0068] Next, in step 108, the control unit 6 displays the generated X-ray image 40 on the display unit 5 (see Figure 2).

[0069] Next, in step 109, the control unit 6 determines whether or not to terminate the generation of the X-ray image 40. For example, the control unit 6 determines whether or not to terminate the generation of the X-ray image 40 based on whether or not there has been an input to terminate the generation of the X-ray image 40. If the generation of the X-ray image 40 is not terminated, the process proceeds to step 101. If the generation of the X-ray image 40 is terminated, the process ends.

[0070] (Effects of the first embodiment) In the first embodiment, the following effects can be obtained.

[0071] In the first embodiment, as described above, the X-ray imaging apparatus 100 comprises an X-ray irradiation unit 1 that irradiates X-rays, an X-ray detection unit 2 having a facing surface 20 facing the X-ray irradiation unit 1 and outputting an image signal based on the X-rays irradiated by the X-ray irradiation unit 1, a collimator 3 that changes the position of the irradiation range 50 of the X-rays irradiated from the X-ray irradiation unit 1 on the facing surface 20, an image generation unit 4 that generates an X-ray image 40 based on the image signal output by the X-ray detection unit 2, a display unit 5 that displays the X-ray image 40 generated by the image generation unit 4, and a control unit 6. The X-ray detection unit 2 has a first region 20a which is a predetermined area on the facing surface 20, and a first mode in which the time required to output an image signal in the predetermined area of ​​the facing surface 20 is relatively large, but the visibility of the X-ray image 40 generated by the image generation unit 4 is relatively high. The output mode can be switched between a first mode, in which the time required to output an image signal within a predetermined range of the opposing surface 20 is relatively small, but the visibility of the X-ray image 40 generated by the image generation unit 4 is relatively low. The control unit 6 determines whether, as a result of the change in the position of the X-ray irradiation range 50 on the opposing surface 20 by the collimator 3, the entire X-ray irradiation range 50 is included in the first region 20a, or whether at least a part of the X-ray irradiation range 50 is included in the second region 20b, which is located within the opposing surface 20 but outside the first region 20a. If it is determined that the state is the first mode, the output mode of the X-ray detection unit 2 is switched to the first mode. If it is determined that the state is the second mode, the output mode of the X-ray detection unit 2 is switched to the second mode.

[0072] As a result, the control unit 6 sets the output mode of the X-ray detection unit 2 to the first mode when the positional relationship between the first region 20a and the second region 20b and the X-ray irradiation area 50 is in the first state, and sets the output mode of the X-ray detection unit 2 to the first mode when it is in the second state. This automatically switches between the first mode, which generates an X-ray image 40 with relatively high visibility, and the second mode, which generates an X-ray image 40 with relatively low visibility. Therefore, the operator can set the output mode of the image signal to be suitable for the positional relationship between the first region 20a and the second region 20b and the X-ray irradiation area 50 without changing the output mode of the image signal of the X-ray detection unit 2. As a result, it is possible to suppress the cumbersome operation and the temporary interruption of the observation of the subject that would otherwise be caused by changing the output mode of the image signal in the X-ray detection unit 2 in response to the movement of the X-ray irradiation area 50.

[0073] Furthermore, in the first embodiment described above, the following additional effects can be obtained by configuring it as follows.

[0074] In other words, in the first embodiment, as described above, the X-ray image 40 is generated as a moving image, the visibility of the X-ray image 40 is determined by at least one of the frame rate and resolution, and the control unit 6 is configured to make the visibility of the X-ray image 40 in the second mode relatively lower by making at least one of the frame rate and resolution of the X-ray image 40 generated based on the image signal output in the second mode lower than at least one of the frame rate and resolution of the X-ray image 40 generated based on the image signal output in the first mode. As a result, by setting the output mode of the image signal to such that at least one of the frame rate or resolution of the X-ray image 40 generated based on the image signal output in the second mode is lower, the visibility of the X-ray image 40 generated based on the image signal output in the second mode can be easily made lower than the visibility of the X-ray image 40 generated based on the image signal output in the first mode. As a result, even when it is necessary to change the image signal output mode depending on the relative position between the X-ray irradiation area 50 and the first region 20a and the second region 20b, by changing to the second mode, the generation of the X-ray image 40 as a moving image can be seamlessly continued while reducing the visibility of the generated X-ray image 40. Furthermore, for example, if the image signal output mode is set to lower either the frame rate or the resolution of the X-ray image 40 generated based on the image signal output in the second mode, the frame rate or resolution of the X-ray image 40 generated based on the image signal output in the first mode can be maintained at the same frame rate or resolution as the X-ray image 40 generated based on the image signal output in the first mode. As a result, even when generating the X-ray image 40 based on the image signal output in the second mode, it is possible to make either the frame rate or the resolution of the generated X-ray image 40 equal to either the frame rate or the resolution of the X-ray image 40 generated based on the image signal output in the first mode, thereby suppressing an extreme decrease in the visibility of the generated X-ray image 40 when set to the second mode.

[0075] Furthermore, in the first embodiment, as described above, an input receiving unit 7 is further provided to receive operator input, and the control unit 6 is configured to set, based on the operator input received via the input receiving unit 7, whether to lower the frame rate of the X-ray image 40 or lower the resolution of the X-ray image 40 when the visibility of the X-ray image 40 generated based on the image signal output in the second mode is lower than the visibility of the X-ray image 40 generated based on the image signal output in the first mode. Here, when the X-ray image 40 is generated based on the image signal output in the second mode, depending on the surgical procedure, the area being photographed, and the operator's preference, there are cases where it is desirable to maintain the frame rate of the generated X-ray image 40 and cases where it is desirable to maintain the resolution. Therefore, by configuring the system as described above, it is possible to set the visibility of the X-ray image 40 generated based on the image signal output in the second mode, such as making the frame rate of the X-ray image 40 generated based on the image signal output in the second mode lower than the frame rate of the X-ray image 40 generated based on the image signal output in the first mode, or making the resolution of the X-ray image 40 generated based on the image signal output in the second mode lower than the resolution of the X-ray image 40 generated based on the image signal output in the first mode. As a result, the visibility of the X-ray image 40 generated based on the image signal output in the second mode can be set according to the surgical procedure, the imaging site, and the operator's preference, thereby improving the operator's convenience (usability).

[0076] [Second Embodiment] Next, a second embodiment will be described with reference to Figures 13 to 18. In this second embodiment, unlike the first embodiment in which the control unit 6 controls the mode in which the X-ray detection unit 2 outputs an image signal from the first mode to the second mode when the X-ray irradiation range 50 moves to a position that spans both the first region 20a and the second region 20b, the control unit 201 modifies the X-ray irradiation range 50 when the X-ray irradiation range 50 (see Figure 15) moves to a position that spans both the first region 20a (see Figure 15) and the second region 20b (see Figure 15), and sets the mode in which the X-ray detection unit 2 outputs an image signal to the first mode, which has relatively higher visibility of the X-ray image 40 compared to the second mode.

[0077] (Configuration of X-ray imaging equipment) As shown in Figure 13, the X-ray imaging apparatus 200 comprises an X-ray irradiation unit 1, an X-ray detection unit 2, a collimator 3, a control unit 201, an image generation unit 4, a display unit 5, an input reception unit 7, and a storage unit 8.

[0078] In the second embodiment, the control unit 201 is configured to control the movement of the region of interest 51 in the X-ray image 40. The control unit 201 is also configured to control the movement of the X-ray irradiation range 50 based on the movement of the region of interest 51. The control unit 201 is also configured to determine whether, as a result of the change in the position of the X-ray irradiation range 50 on the opposing surface 20 by the collimator 3, the X-ray irradiation range 50 is in a first state, where the entire X-ray irradiation range 50 is included in the first region 20a, or whether, as a result of the change in the position of the X-ray irradiation range 50 on the opposing surface 20 by the collimator 3, the X-ray irradiation range 50 is in a second state, where at least a part of the X-ray irradiation range 50 is included in the second region 20b, which is located within the opposing surface 20 but outside the first region 20a. Furthermore, even if the control unit 201 determines that the X-ray irradiation range 50 is in the first state, it is configured to deform the X-ray irradiation range 50 to maintain the first state and to set the output mode of the image signal in the X-ray detection unit 2 to the first mode.

[0079] Furthermore, the memory unit 8 is configured to store the irradiable area 33, which will be described later.

[0080] (Setting the irradiable area) In the second embodiment, as shown in Figure 14, the control unit 201 is configured to control the setting of the irradiable area 33 of the X-ray irradiation unit 1 on the opposing surface 20. The control unit 201 sets the irradiable area 33 based on the operator's input. In the example shown in Figure 14, the irradiable area 33 is set to cover the entire first area 20a. The control unit 201 also stores the set irradiable area 33 in the storage unit 8 (see Figure 13). Specifically, the control unit 201 stores in the storage unit 8 the position information of the pixels 2a set in the irradiable area 33 on the opposing surface 20 of the X-ray detection unit 2.

[0081] (Deformation of the X-ray irradiation area) Next, referring to Figure 15, a configuration in which the control unit 201 (see Figure 13) according to the second embodiment performs control to deform the X-ray irradiation range 50 will be described. Figure 15 shows an example in which the X-ray irradiation range 50 is moved in the Y1 direction, as shown by arrow 80c, from a position where the position of the Y1-side end 50d of the X-ray irradiation range 50 and the position of the Y1-side end 33a of the irradiable area 33 are equal. When the control unit 201 according to the second embodiment moves the X-ray irradiation range 50 so that the end 50d of the X-ray irradiation range 50 is located outside the end 33a of the irradiable area 33, it performs control to deform the shape of the X-ray irradiation range 50 to match the end 33a of the irradiable area 33. In the example shown in Figure 15, the shape of the X-ray irradiation range 50 before movement is square, but the shape of the X-ray irradiation range 50 after movement is deformed to be rectangular.

[0082] (Display of border lines corresponding to the X-ray irradiation area) Next, referring to Figure 16, a configuration in which the control unit 201 (see Figure 13) according to the second embodiment displays a frame 53 corresponding to the X-ray irradiation area 50 (see Figure 15) for the X-ray image 40 will be described.

[0083] As shown in Figure 16, the control unit 201 is configured to superimpose and display a frame line 53 indicating the X-ray irradiation range 50 on the overall X-ray image 42, which is an X-ray image 40 generated based on the image signal output for the entire area of ​​the opposing surface 20. In the second embodiment, the control unit 201 deforms the X-ray irradiation range 50 when moving the X-ray irradiation range 50 so that the end 50d (see Figure 15) of the irradiable area 33 (see Figure 15) is located outside the end 33a (see Figure 15). In this case, if a frame line that does not correspond to the deformation of the X-ray irradiation range 50 is displayed, a frame line 54 including an area that is not actually irradiated with X-rays will be displayed. In this case, an X-ray image 40 will be taken that shows an area different from the X-ray image expected by the operator.

[0084] Therefore, in the second embodiment, the control unit 201 is configured to perform control to deform and display the frame line 53 to match the deformed shape of the X-ray irradiation range 50 when the X-ray irradiation range 50 is moved so that the end 50d of the X-ray irradiation range 50 is located outside the end 33a of the irradiable area 33. In the example shown in Figure 15, the X-ray irradiation range 50 is deformed to become a rectangle, so in the example shown in Figure 16, the frame line 53 is deformed to become a rectangle. The frame line 53 is a line that indicates the area corresponding to the area where X-rays are actually irradiated, and may indicate an area different from the region of interest 51 depending on the deformation of the X-ray irradiation range 50. The positional relationship of the frame line 53 with respect to the overall X-ray image 42 is the same as the positional relationship of the X-ray irradiation range 50 with respect to the opposing surface 20 (see Figure 14) of the X-ray detection unit 2 (see Figure 14). Furthermore, the positional relationship of the X-ray irradiation range 50 with respect to the opposing surface 20 of the X-ray detection unit 2 can be obtained based on positional information acquired from the drive unit that drives the X-ray detection unit 2, the drive unit that drives the collimator 3 (see Figure 13), and the like.

[0085] In the second embodiment, when the X-ray irradiation range 50 is moved so that its end 50d is located outside the end 33a of the irradiable area 33, the X-ray irradiation range 50 is deformed. Therefore, as shown in Figure 17, the image generation unit 4 (see Figure 13) generates an X-ray image 43 in which the portion of the region of interest 51 of the X-ray image 40 that is not included in the deformed X-ray irradiation range 50 is displayed as a padding area 43a. The control unit 201 then displays the X-ray image 43 on the display unit 5. Since the padding area 43a is an area that is not irradiated with X-rays, no image signal is output from the corresponding pixel 2a. Therefore, the padding area 43a is treated as having a pixel value of "0" and is displayed as black or white. The X-ray image 43 shown in Figure 17 is an example in which the padding area 43a is displayed as black.

[0086] (X-ray irradiation range adjustment process) Next, referring to Figure 18, we will explain the process by which the control unit 201 (see Figure 13) adjusts the X-ray irradiation range 50 (see Figure 15) when generating the X-ray image 40 (see Figure 16).

[0087] In step 300, the image generation unit 4 generates an overall X-ray image 42 (see Figure 16), which is an X-ray image 40 generated based on the X-rays detected over the entire area of ​​the opposing surface 20. The control unit 201 then displays the generated overall X-ray image 42 on the display unit 5 (see Figure 13).

[0088] Next, the control unit 201 overlays a frame 53 (see Figure 16) indicating the X-ray irradiation area 50 (see Figure 15) onto the overall X-ray image 42.

[0089] Then, the process proceeds from step 101 to step 103. In step 103, if the moved region of interest 51 is located within the first region 20a, the process proceeds to step 106, and then to step 302. If the moved region of interest 51 is not located within the first region 20a, the process proceeds to step 303.

[0090] If the process proceeds from step 103 through step 106 to step 302, in step 302, the control unit 201 moves the frame line 53 (see Figure 17) to match the movement of the X-ray irradiation range 50. At this time, the control unit 201 does not deform the X-ray irradiation range 50 or the frame line 53. After that, the process proceeds to step 305 via step 104.

[0091] Furthermore, if the process proceeds from step 103 to step 303, in step 303, the control unit 201 deforms the X-ray irradiation range 50. Specifically, the control unit 201 deforms the shape of the X-ray irradiation range 50 to match the edge 33a (see Figure 15) of the irradiable area 33 (see Figure 15).

[0092] Next, in step 304, the control unit 201 deforms the frame line 53. Specifically, the control unit 201 deforms the frame line 53 to match the shape of the deformed X-ray irradiation area 50.

[0093] Subsequently, the process proceeds to step 305 via step 104. In step 305, the image generation unit 4 generates an X-ray image 40. If the process proceeds to step 305 via steps 103, 106, 302, and 104, the image generation unit 4 generates an X-ray image 40 in the same manner as in the first embodiment described above. Also, if the process proceeds to step 305 via steps 103, 303, 304, and 104, the image generation unit 4 generates an X-ray image 43 as shown in Figure 18.

[0094] Next, in step 306, the control unit 201 displays the X-ray image 40 or the X-ray image 43 on the display unit 5.

[0095] Then, in step 109, a decision is made as to whether or not to terminate the generation of X-ray image 40 or X-ray image 43. If the generation of X-ray image 40 or X-ray image 43 is not terminated, the process proceeds to step 101. If the generation of X-ray image 40 or X-ray image 43 is terminated, the process ends.

[0096] The other configurations of the second embodiment are the same as those of the first embodiment described above.

[0097] (Effects of the second embodiment) In the second embodiment, the following effects can be obtained.

[0098] In the second embodiment, as described above, the X-ray imaging apparatus 200 includes an X-ray irradiation unit 1 that irradiates X-rays, an X-ray detection unit 2 having a facing surface 20 facing the X-ray irradiation unit 1 and outputting an image signal based on the X-rays irradiated by the X-ray irradiation unit 1, a collimator 3 that changes the position of the irradiation range 50 of the X-rays irradiated from the X-ray irradiation unit 1 on the facing surface 20, an image generation unit 4 that generates an X-ray image 40 based on the image signal output by the X-ray detection unit 2, a display unit 5 that displays the X-ray image 40 generated by the image generation unit 4, and a control unit 201. The X-ray detection unit 2 has a first region 20a which is a predetermined area on the facing surface 20, and although the time required to output the image signal in the predetermined area of ​​the facing surface 20 is relatively large, the visibility of the X-ray image 40 generated by the image generation unit 4 is relatively high. The output mode can be switched between a first mode and a second mode in which the time required to output the image signal within a predetermined range of the opposing surface 20 is relatively small, but the visibility of the X-ray image 40 generated by the image generation unit 4 is relatively low. The control unit 201 determines whether the X-ray irradiation range 50 is in a first state, where the entire X-ray irradiation range 50 is included in the first region 20a, or in a second state, where at least a part of the X-ray irradiation range 50 is within the opposing surface 20 but outside the first region 20a, as a result of the position of the X-ray irradiation range 50 on the opposing surface 20 by the collimator 3. If it is determined that the second state is in place, the X-ray irradiation range 50 is deformed to maintain the first state, and the output mode of the image signal in the X-ray detection unit 2 is set to the first mode.

[0099] As a result, the mode in which the X-ray detection unit 2 outputs an image signal does not change from the first mode, which has relatively high visibility of the X-ray image 40, due to the movement of the X-ray irradiation range 50. Therefore, it is possible to prevent the operation from becoming complicated and the observation of the subject from being temporarily interrupted, which would otherwise be caused by the operation of changing the mode in which the image signal is output to the second mode as the X-ray irradiation range 50 moves. However, some operators may not need X-ray images 40 of parts of the subject other than the part they wish to observe. For this reason, some operators may prefer that the X-ray irradiation range 50 be set to the first mode, which has relatively high visibility of the generated X-ray image 40, rather than being changed to the second mode, which has relatively low visibility of the generated X-ray image 40. Therefore, in the X-ray imaging apparatus 200 of the second embodiment, even if the control unit 201 determines that a second state is in which at least a part of the X-ray irradiation range 50 is included in the second region 20b as a result of the position change on the opposing surface 20 of the X-ray irradiation range 50 by the collimator 3, it deforms the X-ray irradiation range 50 to maintain the first state and sets the output mode of the image signal in the X-ray detection unit 2 to the first mode. As a result, even if it is determined that a second state is in which at least a part of the X-ray irradiation range 50 is included in the second region 20b, it is possible to maintain the first mode in which only the image signal of pixels 2a located within the first region 20a is output. As a result, it is possible to provide an X-ray imaging apparatus 200 that can meet the needs of an operator who wants the system to be set to a mode in which only the image signal of pixels 2a located within the first region 20a is output, and image signals in the region outside the first region 20a of the X-ray irradiation range 50 are not output.

[0100] Furthermore, in the second embodiment described above, the following additional effects can be obtained by configuring it as follows.

[0101] In other words, in the second embodiment, as described above, the control unit 201 performs the following: control to set the irradiable area 33 of the X-ray irradiation unit 1 on the opposing surface 20; and control to deform the shape of the X-ray irradiation area 50 to match the end 33a of the irradiable area 33 when moving the X-ray irradiation range 50 so that the end 50d of the X-ray irradiation range 50 is located outside the end 33a of the irradiable area 33. This makes it possible to suppress the irradiation of unnecessary X-rays that are not used for imaging outside the irradiable area 33. As a result, unnecessary exposure can be suppressed.

[0102] Furthermore, in the second embodiment, as described above, the control unit 201 performs the following controls: superimpose and display a frame line 53 indicating the X-ray irradiation range 50 on the overall X-ray image 42, which is an X-ray image 40 generated based on the X-rays detected over the entire area of ​​the opposing surface 20; and, when the X-ray irradiation range 50 is moved so that the end 50d of the X-ray irradiation range 50 is located outside the end 33a of the irradiable area 33, deform the frame line 53 to match the shape of the deformed X-ray irradiation range 50. As a result, the frame line 53 is displayed in a deformed state to match the shape of the deformed X-ray irradiation range 50, so the operator can easily grasp the area where X-rays are actually irradiated by checking the deformed frame line 53. As a result, compared to a configuration in which the frame line 53 is not deformed to match the shape of the deformed X-ray irradiation range 50, it is possible to make it easier for the operator to grasp the area where X-rays are actually irradiated, thereby improving the operator's convenience (usability).

[0103] Furthermore, the other effects of the second embodiment are the same as those of the first embodiment described above.

[0104] [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.

[0105] For example, the frame rate and resolution (binning size) of the X-ray image 40 generated based on the image signal output in the first mode in the first embodiment and the second embodiment, and the frame rate and resolution (binning size) of the X-ray image 40 generated based on the image signal output in the second mode are merely examples. If the visibility of the X-ray image generated based on the image signal output in the first mode is improved compared to the visibility of the X-ray image generated based on the image signal output in the first mode, the conditions for reading out the charge may be set to a different fps and binning size.

[0106] Furthermore, in the first embodiment described above, as shown in the second embodiment, the display unit may be configured to display the entire X-ray image, and a frame line may be superimposed on the displayed entire X-ray image.

[0107] Furthermore, in the first embodiment described above, the control unit 6 is configured to set, based on operation input received via the input receiving unit 7, whether to lower the frame rate or lower the resolution of the X-ray image 40 when the visibility of the X-ray image 40 generated based on the image signal output in the second mode is lower than the visibility of the X-ray image 40 generated based on the image signal output in the first mode. However, the present invention is not limited to this. For example, the frame rate in the second mode or the resolution in the second mode may be set in advance and configured not to be changed by the operator's operation input. However, if the frame rate in the second mode or the resolution in the second mode cannot be changed by the operator's operation input, the visibility of the X-ray image generated based on the image signal output in the second mode cannot be set according to the operator's preference, and the operator's convenience (usability) decreases. Therefore, it is preferable that the control unit be configured to allow setting whether to lower the frame rate or lower the resolution when the visibility of the X-ray image generated based on the image signal output in the second mode is lower than the visibility of the X-ray image generated based on the image signal output in the first mode.

[0108] Furthermore, in the first embodiment described above, an example was shown in which the control unit 6 is configured such that the output mode of the image signal in the second mode is lower in either frame rate or resolution than the X-ray image 40 generated based on the image signal output in the first mode. However, the present invention is not limited thereto. For example, the control unit may be configured to set the output mode of the image signal in the second mode to an output mode such that an X-ray image is generated in which both frame rate and resolution are lower than the X-ray image generated based on the image signal output in the first mode.

[0109] Furthermore, while the first and second embodiments described above show examples in which the X-ray imaging apparatus 100 (200) is configured as a so-called fluoroscopy table equipped with a tabletop 9, the present invention is not limited thereto. For example, the present invention can be applied to devices other than fluoroscopy tables as long as they are X-ray imaging apparatuses that capture X-ray images as moving images.

[0110] Furthermore, while the first and second embodiments described above show an example configuration in which the collimator 3 (X-ray irradiation range adjustment unit) has first shielding vanes 131 to fourth shielding vanes 134 and fifth shielding vanes 141 to eighth shielding vanes 144, the present invention is not limited thereto. The collimator (X-ray irradiation range adjustment unit) can have any configuration as long as the X-ray irradiation range can be changed.

[0111] Furthermore, while the first and second embodiments described above show examples in which the X-ray detection unit 2 has a first region 20a and a second region 20b on the opposing surface 20, the present invention is not limited thereto. The X-ray detection unit may have three or more regions on the opposing surface.

[0112] Furthermore, although the process by which the control unit 6 in the first embodiment changes the mode in which it outputs an image signal from the X-ray detection unit 2, and the process by which the control unit 201 in the second embodiment adjusts the X-ray irradiation range 50 have been described using a flow-driven flowchart that processes the processes sequentially according to the processing flow, the present invention is not limited thereto. In the present invention, the processing performed by the control unit may be carried out by event-driven processing, which executes the processing on an event-by-event basis. In this case, it may be carried out as a completely event-driven system, or a combination of event-driven and flow-driven systems may be used.

[0113] [Pattern] Those skilled in the art will understand that the exemplary embodiments described above are specific examples of the following embodiments.

[0114] (Item 1) An X-ray irradiation unit that irradiates with X-rays, An X-ray detection unit having a facing surface opposite to the X-ray irradiation unit and outputting an image signal based on the X-rays irradiated by the X-ray irradiation unit, An irradiation range changing unit that changes the position of the irradiation range of the X-rays irradiated from the X-ray irradiation unit on the opposing surface, An image generation unit generates an X-ray image based on the image signal output by the X-ray detection unit, A display unit that displays the X-ray image generated by the image generation unit, It comprises a control unit and, The aforementioned X-ray detection unit is, Having a first region which is a predetermined region on the opposing surface, The output mode can be switched between a first mode in which the time required to output the image signal in a predetermined range of the opposing surface is relatively large, but the visibility of the X-ray image generated by the image generation unit is relatively high, and a second mode in which the time required to output the image signal in a predetermined range of the opposing surface is relatively small, but the visibility of the X-ray image generated by the image generation unit is relatively low. The control unit, As a result of changing the position of the X-ray irradiation range on the opposing surface by the irradiation range changing unit, it is determined whether the state is a first state in which the entire X-ray irradiation range is included in the first region, or a second state in which at least a part of the X-ray irradiation range is included in a second region located within the opposing surface but outside the first region. (a) If it is determined that the first state is present, the output mode of the X-ray detection unit is switched to the first mode. (b) If it is determined that the second state is present, the output mode of the X-ray detection unit is switched to the second mode. X-ray imaging device.

[0115] (Item 2) The aforementioned X-ray image is generated as a moving image, The visibility of the aforementioned X-ray image is determined by at least one of the frame rate and resolution. The X-ray imaging apparatus according to item 1, wherein the control unit is configured to lower the visibility of the X-ray image in the second mode by making at least one of the frame rate and resolution of the X-ray image generated based on the image signal output in the second mode lower than at least one of the frame rate and resolution of the X-ray image generated based on the image signal output in the first mode.

[0116] (Item 3) It further includes an input receiving unit that receives user input, The X-ray imaging apparatus according to item 1 or 2, wherein the control unit is configured to lower the frame rate of the X-ray image or lower the resolution of the X-ray image when the visibility of the X-ray image generated based on the image signal output in the second mode is lower than the visibility of the X-ray image generated based on the image signal output in the first mode, based on the operation input input received via the input receiving unit.

[0117] (Item 4) An X-ray irradiation unit that irradiates with X-rays, An X-ray detection unit having a facing surface opposite to the X-ray irradiation unit and outputting an image signal based on the X-rays irradiated by the X-ray irradiation unit, An irradiation range changing unit that changes the position of the irradiation range of the X-rays irradiated from the X-ray irradiation unit on the opposing surface, An image generation unit generates the X-ray image based on the image signal output by the X-ray detection unit, A display unit that displays the X-ray image generated by the image generation unit, It comprises a control unit and, The aforementioned X-ray detection unit is, Having a first region which is a predetermined region on the opposing surface, The output mode can be switched between a first mode in which the time required to output the image signal in a predetermined range of the opposing surface is relatively large, but the visibility of the X-ray image generated by the image generation unit is relatively high, and a second mode in which the time required to output the image signal in a predetermined range of the opposing surface is relatively small, but the visibility of the X-ray image generated by the image generation unit is relatively low. The control unit, As a result of changing the position of the X-ray irradiation range on the opposing surface by the irradiation range changing unit, it is determined whether the state is a first state in which the entire X-ray irradiation range is included in the first region, or a second state in which at least a part of the X-ray irradiation range is included in a second region located within the opposing surface but outside the first region. If it is determined that the second state is present, the irradiation range of the X-rays is modified to maintain the first state, and the output mode of the image signal in the X-ray detection unit is set to the first mode. X-ray imaging device.

[0118] (Item 5) The control unit, Control for setting the irradiable area for X-rays irradiated from the X-ray irradiation unit on the opposing surface, The X-ray imaging apparatus according to item 4, which, when moving the X-ray irradiation range such that the edge of the X-ray irradiation range is located outside the edge of the irradiable area, performs control to deform the shape of the X-ray irradiation range to match the edge of the irradiable area.

[0119] (Item 6) The control unit, Control to superimpose and display a frame line indicating the irradiation range of the X-rays onto the overall X-ray image, which is an X-ray image generated based on the X-rays detected in the entire area of ​​the opposing surface, The X-ray imaging apparatus according to item 5, which performs control to deform and display the frame line to match the deformed shape of the X-ray irradiation area when the X-ray irradiation area is moved such that the edge of the X-ray irradiation area is located outside the edge of the irradiable area. [Explanation of Symbols]

[0120] 1 X-ray irradiation section 2 X-ray detection unit 3. Collimator (part for changing the irradiation range) 4 Image generation unit 5 Display section 6, 201 Control Unit 7 Input Reception Section 20 Opposing surface (opposing surface of the X-ray detection unit) 20a First region (a predetermined region on the opposing surface) 20b Second region (a region located within the opposing plane but outside the first region) 32 thresholds 33 Irradiation possible area 33a Edge of the irradiable area 40, 41, 43 X-ray images 42 Overall X-ray image 50, 50a, 50b X-ray irradiation range 51 Areas of Interest 53. Border lines (border lines indicating the X-ray irradiation area) 100, 200 X-ray imaging equipment

Claims

1. An X-ray irradiation unit that irradiates with X-rays, An X-ray detection unit having a facing surface opposite to the X-ray irradiation unit and outputting an image signal based on the X-rays irradiated by the X-ray irradiation unit, An irradiation range changing unit that changes the position of the irradiation range of the X-rays irradiated from the X-ray irradiation unit on the opposing surface, An image generation unit generates an X-ray image based on the image signal output by the X-ray detection unit, A display unit that displays the X-ray image generated by the image generation unit, It comprises a control unit and, The aforementioned X-ray detection unit is Having a first region which is a predetermined region on the opposing surface, The output mode can be switched between a first mode in which the time required to output the image signal in a predetermined range of the opposing surface is relatively large, but the visibility of the X-ray image generated by the image generation unit is relatively high, and a second mode in which the time required to output the image signal in a predetermined range of the opposing surface is relatively small, but the visibility of the X-ray image generated by the image generation unit is relatively low. The control unit, As a result of changing the position of the X-ray irradiation range on the opposing surface by the irradiation range changing unit, it is determined whether the state is a first state in which the entire X-ray irradiation range is included in the first region, or a second state in which at least a part of the X-ray irradiation range is included in a second region located within the opposing surface but outside the first region. (a) If it is determined that the first state is present, the output mode of the X-ray detection unit is switched to the first mode. (b) If it is determined that the second state is present, the output mode of the X-ray detection unit is switched to the second mode. X-ray imaging device.

2. The aforementioned X-ray image is generated as a moving image, The visibility of the aforementioned X-ray image is determined by at least one of the frame rate and resolution. The X-ray imaging apparatus according to claim 1, wherein the control unit is configured to relatively reduce the visibility of the X-ray image in the second mode by making at least one of the frame rate and resolution of the X-ray image generated based on the image signal output in the second mode lower than at least one of the frame rate and resolution of the X-ray image generated based on the image signal output in the first mode.

3. It further includes an input receiving unit that receives user input, The X-ray imaging apparatus according to claim 2, wherein the control unit is configured to set, based on the operation input received via the input receiving unit, whether to lower the frame rate of the X-ray image or lower the resolution of the X-ray image when the visibility of the X-ray image generated based on the image signal output in the second mode is lower than the visibility of the X-ray image generated based on the image signal output in the first mode.

4. An X-ray irradiation unit that irradiates with X-rays, An X-ray detection unit having a facing surface opposite to the X-ray irradiation unit and outputting an image signal based on the X-rays irradiated by the X-ray irradiation unit, An irradiation range changing unit that changes the position of the irradiation range of the X-rays irradiated from the X-ray irradiation unit on the opposing surface, An image generation unit generates an X-ray image based on the image signal output by the X-ray detection unit, A display unit that displays the X-ray image generated by the image generation unit, It comprises a control unit and, The aforementioned X-ray detection unit is Having a first region which is a predetermined region on the opposing surface, The output mode can be switched between a first mode in which the time required to output the image signal in a predetermined range of the opposing surface is relatively large, but the visibility of the X-ray image generated by the image generation unit is relatively high, and a second mode in which the time required to output the image signal in a predetermined range of the opposing surface is relatively small, but the visibility of the X-ray image generated by the image generation unit is relatively low. The control unit, As a result of changing the position of the X-ray irradiation range on the opposing surface by the irradiation range changing unit, it is determined whether the state is a first state in which the entire X-ray irradiation range is included in the first region, or a second state in which at least a part of the X-ray irradiation range is included in a second region located within the opposing surface but outside the first region. If it is determined that the second state is present, the irradiation range of the X-rays is modified to maintain the first state, and the output mode of the image signal in the X-ray detection unit is set to the first mode. X-ray imaging device.

5. The control unit, Control for setting the irradiable area for X-rays irradiated from the X-ray irradiation unit on the opposing surface, The X-ray imaging apparatus according to claim 4, wherein when the X-ray irradiation range is moved such that the end of the X-ray irradiation range is located outside the end of the irradiable area, control is performed to deform the shape of the X-ray irradiation range to match the end of the irradiable area.

6. The control unit, Control to superimpose and display a frame line indicating the irradiation range of the X-rays onto the overall X-ray image, which is an X-ray image generated based on the X-rays detected in the entire area of ​​the opposing surface, The X-ray imaging apparatus according to claim 5, wherein when the X-ray irradiation range is moved such that the end of the X-ray irradiation range is located outside the end of the irradiable area, the frame line is deformed and displayed to match the deformed shape of the X-ray irradiation range.

Images