X-ray imaging device and method for controlling x-ray imaging device

Abstract

In this X-ray imaging device (100), a control unit (10) generates a plurality of selection X-ray images (A1-A7, B1-B7, C1-C7, and D1-D7) having different viewing characteristics corresponding to a plurality of selection parameters extracted from a storage unit (7), sets a selection parameter used for the generation of a selected one selection X-ray image (D5) as an observation parameter (P1) for generating an observation X-ray image (I1), and stores the selection parameter in the storage unit (7).

Description

X-ray imaging device and control method for X-ray imaging device

[0001] The present invention relates to an X-ray imaging apparatus and a control method for an X-ray imaging apparatus, and more particularly to an X-ray imaging apparatus that displays an X-ray imaging image and a control method for an X-ray imaging apparatus.

[0002] 2. Description of the Related Art Conventionally, X-ray diagnostic (imaging) devices that display X-ray images have been known. Such X-ray diagnostic (imaging) devices are disclosed, for example, in Japanese Patent Application Laid-Open No. 2019-145434.

[0003] The X-ray diagnostic apparatus described in JP 2019-145434 A includes an X-ray tube, an X-ray detector that detects X-rays, an image generating circuit that generates an X-ray image based on the output of the X-ray detector, and a display that displays the X-ray image. JP 2019-145434 A discloses that adjusting the output of the tube voltage, tube current, and exposure time leads to deterioration (changes) in the image quality of the X-ray image. JP 2019-145434 A also discloses that the output intensity of the X-rays is controlled by the tube voltage, tube current, and exposure time, and that the tube voltage, tube current, and exposure time are adjusted by a service technician.

[0004] JP 2019-145434 A

[0005] In the above-mentioned Japanese Patent Application Laid-Open No. 2019-145434, the output of the tube voltage, tube current, and irradiation time, which are related to the image quality of the X-ray image, are adjusted by a service technician. Here, the image quality of the X-ray image is affected by various parameters, such as image processing parameters, in addition to the tube voltage, tube current output, and irradiation time in the X-ray irradiator. Therefore, it is difficult for a user to know all of the parameters that should be changed to obtain an X-ray image of desired image quality, and these parameters related to the image quality of the X-ray image are generally set or adjusted by a service technician.

[0006] However, because the image quality of an X-ray image displayed on an X-ray imaging device varies greatly depending on the user's preferences, a different user may want to change the settings when acquiring an X-ray image. Furthermore, even when the same user uses the device, they may want to adjust the settings again after completing the settings once. Having to ask a service technician for each setting or adjustment is a significant burden on the service technician, and it takes time for the parameters to be set, which is inconvenient for the user. Therefore, there is a need for an X-ray imaging device and a control method for an X-ray imaging device that allows the user to set parameters for changing the image quality of an X-ray image without having to ask a service technician for adjustments.

[0007] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide an X-ray imaging apparatus and a control method for an X-ray imaging apparatus that enable parameters to be set for changing the image quality of X-ray images without having to request adjustments from a service technician.

[0008] An X-ray imaging device in a first aspect of the present invention includes an X-ray irradiation unit that irradiates an object with X-rays, an X-ray detection unit that detects the X-rays irradiated from the X-ray irradiation unit, a control unit that generates an X-ray image based on an X-ray detection signal detected by the X-ray detection unit, and a memory unit that stores a plurality of selection parameters that adjust the visibility characteristics of the X-ray image.The control unit is configured to generate a plurality of selection X-ray images, each having different visibility characteristics corresponding to the plurality of selection parameters extracted from the memory unit, accept a user's selection of one selection X-ray image from among the plurality of selection X-ray images, set the selection parameters used to generate the one selection X-ray image selected by the user as observation parameters for generating an observation X-ray image, and store them in the memory unit.

[0009] A control method for an X-ray imaging device in a second aspect of the present invention is a control method for an X-ray imaging device that includes a control unit that generates an X-ray image based on a detection signal of X-rays irradiated onto an object to be imaged, and a memory unit that stores a plurality of selection parameters that adjust the visibility characteristics of the X-ray image, and includes an extraction and generation step in which the control unit generates a plurality of selection X-ray images, each having different visibility characteristics corresponding to the plurality of selection parameters extracted from the memory unit; an acceptance step in which the control unit accepts the user's selection of one selection X-ray image from the plurality of selection X-ray images; a setting step in which the control unit sets the selection parameters used to generate the selected one selection X-ray image as observation parameters for generating a new observation X-ray image; and a storage step in which the memory unit stores the observation parameters.

[0010] In a first aspect of the X-ray imaging device and a second aspect of the control method for an X-ray imaging device, the control unit generates a plurality of selection X-ray images, each having different visibility characteristics, corresponding to a plurality of selection parameters extracted from a storage unit, accepts a user's selection of one selection X-ray image from the plurality of selection X-ray images, sets the selection parameters used to generate the selection X-ray image selected by the user as observation parameters for generating an observation X-ray image, and stores the selection parameters in the storage unit. This allows the user to set observation parameters to be used when performing X-ray imaging on a patient or the like based on the user's selection of one selection X-ray image from the selection X-ray images generated by the control unit, and stores and saves the observation parameters in the storage unit. As a result, parameters for changing the image quality of an X-ray image can be set without having to request adjustment from a service technician.

[0011] FIG. 1 is a diagram showing an X-ray imaging apparatus in an imaging room according to this embodiment. FIG. 2 is a block diagram for explaining the X-ray imaging apparatus according to this embodiment. FIG. 3 is an example of an observation X-ray image according to this embodiment. FIG. 4 is an example of a plurality of selection X-ray images displayed on a display unit according to this embodiment. FIG. 5 is another example of a plurality of selection X-ray images displayed on a display unit according to this embodiment. FIG. 6 is another example of a plurality of selection X-ray images displayed on a display unit according to this embodiment. FIG. 7 is a diagram for explaining the visibility characteristics of a plurality of selection X-ray images taken with adjustment parameters changed according to this embodiment. FIG. 8 is a flow chart showing processing by a control unit for updating and setting an observation parameter set according to this embodiment. FIG. 9 is a diagram for explaining observation parameters set for each user and displayed on a display unit according to this embodiment. FIG. 10 is a diagram for explaining the visibility characteristics of a plurality of selection X-ray images after image processing according to this embodiment.

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0013] The configuration of an X-ray imaging apparatus 100 according to an embodiment will be described with reference to FIGS. 1 and 2. FIG.

[0014] (Configuration of X-ray imaging device) As shown in FIG. 1, the X-ray imaging device 100 of this embodiment includes a tabletop 1, an imaging unit 2, a moving unit 3, a display unit 4, a touch panel 5, an operation unit 6, a memory unit 7, and a control unit 10.

[0015] A phantom F, which is a human body model serving as a subject, is placed on the top plate 1. The top plate 1 is formed as a rectangular flat plate in a plan view. The phantom F is placed on the top plate 1 so that the head-to-foot direction of the phantom F is along the long side of the top plate 1 and the left-to-right direction of the phantom F is along the short side of the top plate 1. In this specification, the long side of the top plate 1 is defined as the X direction. The direction of the short side of the top plate 1 is defined as the Y direction. The direction perpendicular to the X and Y directions is defined as the Z direction. The head-to-foot direction of the phantom F is the direction along the straight line connecting the head and feet of the phantom F.

[0016] The imaging unit 2 includes an X-ray irradiator 21 and an X-ray detector 22. The imaging unit 2 is configured to capture X-ray images such as an observation X-ray image I1 (see FIG. 3 ) of a subject or a selection X-ray image A1 (see FIG. 4 ) of a phantom F. The X-ray source 21A included in the X-ray irradiator 21 is disposed on one side of the tabletop 1 in the Z direction. The X-ray source 21A is configured to irradiate the phantom F or an actual patient with X-rays when a voltage is applied by an X-ray tube driver (not shown). The X-ray source 21A also includes a collimator 21B that can adjust the X-ray irradiation field, which is the range of X-ray irradiation. As shown in FIG. 1 , the X-ray source 21A is attached to the tip of one side of a C-arm 23.

[0017] The X-ray detection unit 22 is configured to detect X-rays irradiated from the X-ray source 21A and transmitted through the phantom F. The X-ray detection unit 22 includes, for example, an FPD (Flat Panel Detector). The X-ray detection unit 22 is attached to the tip of the other side of the C-arm 23 (the side opposite the X-ray source 21A). The C-arms 23 are also positioned so that their tip portions sandwich the tabletop 1. That is, the X-ray detection unit 22 is disposed on the other side of the tabletop 1 (the side opposite the X-ray source 21A), sandwiching the tabletop 1 between them. As a result, the X-ray imaging apparatus 100 is configured to be able to capture an X-ray image by irradiating X-rays from the X-ray source 21A with the phantom F placed on the tabletop 1 and detecting the X-rays transmitted through the phantom F with the X-ray detection unit 22.

[0018] The top plate moving unit 31 serving as the moving unit 3 is configured to move the position of the top plate 1 on which the phantom F is placed. The top plate moving unit 31 also includes a C-arm 23 that integrally holds the X-ray irradiation unit 21 and the X-ray detection unit 22. The top plate moving unit 31 is configured to move the top plate 1 under the control of the control unit 10 so as to change the relative position between the top plate 1 and the imaging unit 2. Specifically, the top plate moving unit 31 is configured to move the top plate 1 in any of the X, Y, and Z directions to change the relative position between the top plate 1 and the imaging unit 2. The top plate moving unit 31 includes a linear motion mechanism that can move the top plate 1 in the X direction, a linear motion mechanism that can move the top plate 1 in the Y direction, and a linear motion mechanism that can move the top plate 1 in the Z direction. Each linear motion mechanism includes, for example, a ball screw or a linear motor. In this embodiment, the top plate 1 can be moved automatically by the top plate moving unit 31 or manually by an operator.

[0019] The rotation mechanism 32 serving as the moving unit 3 is configured to be able to rotate the imaging unit 2 by rotating the C-arm 23 under the control of the control unit 10. The rotation mechanism 32 includes a moving mechanism that slides the C-arm 23 along the outer periphery of the C-arm 23. The rotation mechanism 32 is configured to be able to rotate the C-arm 23 around an axis along the longitudinal direction (X direction) of the tabletop 1 and around an axis along the lateral direction (Y direction) of the tabletop 1. The rotation mechanism 32 includes, for example, a motor.

[0020] The display unit 4 and the touch panel 5 include a liquid crystal display, an organic EL display, or the like. The display unit 4 is connected to the control unit 10 via a video interface such as HDMI (registered trademark). The display unit 4 is fixed to the ceiling of an imaging room where X-ray fluoroscopy is performed, for example. In this embodiment, the touch panel 5 is a display provided in the X-ray imaging apparatus 100, and also functions as an operation unit 6 that accepts operations on the X-ray imaging apparatus 100 by users such as doctors.

[0021] The operation unit 6 includes, for example, a mouse and a keyboard. The operation unit 6 is configured to receive input operations from an operator. The operation unit 6 is configured to transmit the received input operations to the control unit 10.

[0022] The storage unit 7 includes, for example, a hard disk drive (HDD) or nonvolatile memory. The storage unit 7 stores programs used in processing by the image generation unit 13. The storage unit 7 also stores image information captured by the imaging unit 2. The storage unit 7 is configured to store a plurality of selection parameters, including adjustment parameters for adjusting the imaging conditions of the imaging unit 2 and processing parameters for performing image processing on X-ray images, as well as observation parameters P1 to P3 (see FIG. 10). The storage unit 7 is also disposed near and connected to the control unit 10, and transmits the various stored information.

[0023] The control unit 10 includes an imaging control unit 11 that controls the imaging unit 2 to capture X-ray images with various adjustment parameters changed so as to change the visibility characteristics of the X-ray image. The control unit 10 also includes a movement control unit 12 that controls a tabletop moving unit 31 to move the tabletop 1 and the imaging unit 2 relative to each other and controls a rotation mechanism 32 to rotate the imaging unit 2. The control unit 10 is a computer including, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The control unit 10 also functions as an image generation unit 13 by executing a predetermined control program. The image generation unit 13 is a software functional block within the control unit 10 and is configured to function based on command signals from the control unit 10 (hardware). The control unit 10 is configured to control data communication with systems external to the X-ray imaging apparatus 100, for example.

[0024] (Setting Observation Parameters) Here, detailed operations performed by the control unit 10 when setting the observation parameters P1 to P3 (see FIG. 10 ) will be described using FIGS. 1 to 8 . In this embodiment, the observation parameters P1 to P3 stored in the storage unit 7 are a protocol made up of multiple types of parameters that are actually used by the user when imaging a patient, and include adjustment parameters and processing parameters. The image quality of the acquired X-ray image of the patient is changed based on changes to these observation parameters P1 to P3. Each user registers the observation parameters P1 to P3, with various parameters changed according to their preferences, in the storage unit 7, and when imaging a patient, X-ray fluoroscopy is performed using the registered observation parameters P1 to P3 (see FIG. 10 ).

[0025] In this embodiment, the selection parameters stored in the storage unit 7 are protocols consisting of multiple types of parameters for generating selection X-ray images that the user refers to when setting the observation parameters P1 to P3, and include adjustment parameters and processing parameters. Furthermore, multiple types of selection parameters are registered in advance in the storage unit 7 when the X-ray imaging apparatus 100 is shipped.

[0026] The image generation unit 13 is configured to generate an X-ray image based on the detection signal detected by the X-ray detection unit 22. The image generation unit 13 includes, for example, a processor such as an FPGA (field-programmable gate array) configured for image processing. Note that in this embodiment, the X-ray image is, for example, an angiographic image obtained by X-ray imaging of blood vessels (a blood vessel model) in the head of the phantom F.

[0027] The image generator 13 is configured to generate one observation X-ray image I1, as shown in FIG. 3, based on one observation parameter P1 (see FIG. 10). Specifically, the image generator 13 generates one observation X-ray image I1 based on a detection signal detected by the X-ray detector 22 of X-rays irradiated based on adjustment parameters included in the observation parameter P1. If the observation parameter P1 includes processing parameters for image processing, the observation X-ray image I1 is generated by performing image processing on the X-ray image generated based on the detection signal. The observation parameter P1 is selected by the user from among multiple observation parameters P1 to P3 stored in the storage unit 7, for example.

[0028] The image generator 13 is configured to generate X-ray images such as a selection X-ray image A1 and a selection X-ray image B1 as shown in FIG. 4 based on the selection parameters extracted from the storage unit 7. FIG. 4 shows two generated selection X-ray images A1 and B2 displayed on the display unit 4. Specifically, the image generator 13 generates two selection X-ray images A1 and B1 based on X-ray detection signals detected by the X-ray detector 22, in accordance with the adjustment parameters included in the two selection parameters. If the selection parameters include processing parameters for image processing, the image generator 13 performs image processing on the X-ray images generated based on the detection signals, thereby generating two selection X-ray images such as a selection X-ray image C1 and a selection X-ray image D1 as shown in FIG. 5. These two selection parameters are extracted by the controller 10 from multiple selection parameters stored in the storage unit 7 based on, for example, one observation parameter P1 selected by the user.

[0029] Furthermore, the image generator 13 generates a plurality of selection X-ray images A1 and B1 (see FIG. 4) having visibility characteristics different from those of the observation X-ray image I1 (see FIG. 3) corresponding to the observation parameters P1 selected by the user from the storage unit 7. In this embodiment, the observation X-ray image I1 has two visibility characteristics that are in a trade-off relationship, for example, "noise suppressed (low noise)" and "blood vessels can be clearly seen (high clarity)." At this time, the controller 10 extracts from the storage unit 7 selection parameters for generating selection X-ray images A1 and B1 having visibility characteristics different (to different degrees) from those of the observation X-ray image I1. Specifically, the control unit 10 extracts from the memory unit 7 selection parameters for generating a selection X-ray image A1 in which the tendency of the visual characteristic of the observation X-ray image I1, that is, "noise is suppressed," is enhanced, and also extracts from the memory unit 7 selection parameters for generating a selection X-ray image B1 in which the tendency of the visual characteristic of "blood vessels can be seen clearly" is enhanced.

[0030] 6 , which have different visual characteristics from the one selection X-ray image A1 selected by the user. After receiving the selection of one selection X-ray image A1 from the user, the control unit 10 extracts two selection parameters from the storage unit 7 so as to include selection parameters for generating a selection X-ray image A2 that enhances the visual characteristic tendency of the selection X-ray image A1. Specifically, based on the user's selection of the selection X-ray image A1, which has an enhanced visual characteristic tendency of "noise suppressed (low noise)," the control unit 10 extracts selection X-ray parameters from the storage unit 7 so as to include a selection X-ray image A2 that further enhances the visual characteristic tendency of "noise suppressed." In this embodiment, the selection X-ray image A3 generated based on the selection X-ray image A1 has a degree of visual recognition specificity that is between that of the selection X-ray image A1 and that of the selection X-ray image A2.

[0031] In addition, when the control unit 10 receives a user's selection of one selection X-ray image B1, which has a stronger tendency for the visual characteristic of "blood vessels can be seen clearly (high clarity)," from among the two selection X-ray images A1 and B1 (see Figure 4), the control unit 10 extracts two selection X-ray parameters from the memory unit 7 so as to include selection X-ray parameters for generating a selection X-ray image B3, as shown in Figure 7, which has an even stronger tendency for the visual characteristic of "blood vessels can be seen clearly."

[0032] The control unit 10 is also configured to repeat the process of receiving one selection X-ray image from the user and generating the selection X-ray image by the image generation unit 13 a predetermined number of times, and to update and set the parameters used in generating the last selected selection X-ray image as the observation parameters P1 upon receiving a selection termination operation from the user. As shown in Fig. 8 , the selection X-ray images A1 to A7 and B1 to B7 are generated so that their visibility characteristics change each time they are selected by the user. For example, as shown in Fig. 8 , if the user selects selection X-ray image A1, which tends to have visibility characteristics of "suppressed noise" and "clear visibility of blood vessels" compared to selection X-ray image B1 (low noise and low clarity), selection X-ray image A2, which tends to have even less noise and lower clarity than selection X-ray image A1, and selection X-ray image A3, which has noise and clarity intermediate between those of selection X-ray image A1 and selection X-ray image A2, are generated. 8 shows that when selection X-ray image A2, which tends to have less noise and less definition, is selected, selection X-ray image A4, which tends to have even less noise and less definition than selection X-ray image A2, and selection X-ray image A5, which has noise and definition intermediate between selection X-ray image A2 and selection X-ray image A4, are generated. The same applies to the other selection X-ray images.

[0033] The control unit 10 extracts a plurality of selection parameters from the storage unit 7 so that the amount of change in the selection parameters, which are changed to enhance the tendency of the visual recognition characteristics of the X-ray images, becomes smaller each time the selection of one selection X-ray image by the user is accepted. That is, the amount of change in the parameters that changes when selection X-ray image A2 is generated based on the selection of selection X-ray image A1 is smaller than the amount of change in the parameters that changes when selection X-ray image A4 is generated based on the selection of selection X-ray image A2.

[0034] (Control Method for Setting Observation Parameters According to This Embodiment) Next, the processing flow of the control method for setting the observation parameters P1 of this embodiment of the X-ray imaging apparatus 100 will be described with reference to Figures 1 to 10. Note that steps S1 to S13 are controls executed by the control unit 10 of the X-ray imaging apparatus 100.

[0035] First, in step S1 of the flowchart shown in Fig. 9, the control unit 10 performs an observation parameter selection receiving step of receiving the selection of an observation parameter P1 whose settings will be updated. Specifically, in step S1, the user operates the operation unit 6 to select the observation parameter P1 that the user wishes to update from among the multiple observation parameters P1 to P3 displayed on the display unit 4 and stored in the storage unit 7, as shown in Fig. 10. Based on this user's selection operation, the control unit 10 receives that one observation parameter P1 whose settings will be updated has been selected. Then, the process proceeds to step S2.

[0036] Next, in step S2, the control unit 10 performs a first extraction step of extracting two types of selection parameters from the storage unit 7 based on the selected observation parameters P1. Specifically, in step S2, two types of selection parameters are extracted from the storage unit 7 for generating selection X-ray images A1 and B1 (see FIG. 4) that have different visibility from the observation X-ray image I1 (see FIG. 3) generated based on the selected observation parameters P1. At this time, the control unit 10 extracts the two types of selection parameters from the storage unit 7 so as to include selection parameters for generating selection X-ray image A1 that enhances the tendency of the visibility characteristics of observation X-ray image I1 generated based on the current observation parameters P1. Note that in this embodiment, the selection parameters extracted in step S2 are adjustment parameters for adjusting the imaging conditions of the imaging unit 2 (conditions for adjusting the tube current, tube voltage, and X-ray exposure time applied to the X-ray source 21A, the sensitivity of the X-ray detection unit 22, etc.) that change the X-ray dose detected by the X-ray detection unit 22. Then, the process proceeds to step S3.

[0037] Next, in step S3, the control unit 10 performs a first image generation step of performing X-ray fluoroscopy based on the selection parameters to generate two types of selection X-ray images A1 and B1 (see FIG. 4). Specifically, the control unit 10 changes the imaging conditions of the imaging unit 2 based on the two types of extracted selection parameters, performs X-ray fluoroscopy on the phantom F, and generates selection X-ray images A1 and B1 under each imaging condition. Then, the process proceeds to step S4.

[0038] Next, in step S4, the control unit 10 performs a first display step of displaying two types of selection X-ray image A1 and selection X-ray image B1 on the display unit 4 (see FIG. 1). In this embodiment, the control unit 10 also displays the selection X-ray image A1 and selection X-ray image B1 on the touch panel 5 (see FIG. 1). Thereafter, the process proceeds to step S5.

[0039] Next, in step S5, the control unit 10 performs a first receiving step of receiving a user's selection of one selection X-ray image A1 from the two selection X-ray images A1 and B1 displayed on the display unit 4 and touch panel 5. Specifically, in step S5, the user looks at the display unit 4 or touch panel 5 and operates the operation unit 6 or touch panel 5 to select one selection X-ray image A1 with the desired image quality. Based on this user's selection operation, the control unit 10 receives that one selection parameter has been selected. Then, the process proceeds to step S6.

[0040] Next, in step S6, the control unit 10 accepts a selection as to whether or not the setting of the adjustment parameters for the imaging unit 2 has been completed. In step S6, if the user is not satisfied with the image quality of the selection X-ray image A1 selected in step S5 and wishes to further change the image quality of the X-ray image, the user operates the operation unit 6 to input to the control unit 10 that the setting of the adjustment parameters has not been completed. If the control unit 10 accepts that the setting of the adjustment parameters has not been completed, the control unit 10 returns to step S2 and repeats the processes of steps S2 to S5 again. Note that, when returning to step S2, the control unit 10 extracts two types of selection parameters from the storage unit 7 so as to include selection parameters for generating a selection X-ray image A4 (see FIG. 8 ) that enhances the tendency of the visibility characteristics of the selection X-ray image selected in step S5.

[0041] In step S6, if the user is satisfied with the image quality of the selection X-ray image selected in step S5 and does not need to change the adjustment parameters any further, the user operates the operation unit 6 to input to the control unit 10 that the adjustment parameter setting has been completed. When the control unit 10 receives that the adjustment parameter setting has been completed, the control unit 10 proceeds to the processing of step S7. In this embodiment, for example, a case will be described in which the adjustment parameter setting has been completed in step S5 with the selection X-ray image A4 selected last.

[0042] Next, in step S7, the control unit 10 accepts a selection of whether or not to set processing parameters for the X-ray image. In this step S7, if the user wants to perform image processing collectively on X-ray images to be acquired in the future, the processing parameters are set so that the updated observation parameters P1 are set in a state including the processing parameters. If the control unit 10 accepts that processing parameters are to be set, the process proceeds to step S8. Note that if the control unit 10 accepts that processing parameters are not to be set, the process proceeds to step S13.

[0043] Next, in step S8, the control unit 10 performs a second extraction process in which two types of selection parameters are extracted from the storage unit 7. Similar to the first extraction process in step S2, the second extraction process in step S8 extracts two types of selection parameters from the storage unit 7 so as to include selection parameters for generating a selection X-ray image C1 in which the tendency of the visual recognition characteristics of the X-ray image is enhanced. Note that in this embodiment, the selection parameters extracted in step S2 are processing parameters for adjusting image processing conditions (conditions such as brightness adjustment, contrast adjustment, and strength of noise removal filter processing) performed on an already acquired X-ray image. Then, the process proceeds to step S9.

[0044] Next, in step S9, the control unit 10 performs image processing based on the selection parameters extracted from the storage unit 7 to perform a second image generation step of generating two selection X-ray images C1 and D1 (see FIG. 5 ). Specifically, the control unit 10 performs image processing based on the two extracted selection parameters (processing parameters) on the selection X-ray image A4, the selection of which was last accepted in step S5, to generate the selection X-ray image C1 and the selection X-ray image D1. Thereafter, the process proceeds to step S10.

[0045] Next, in step S10, the control unit 10 performs a second display step in which two types of selection X-ray image C1 and selection X-ray image D1 (see FIG. 5) are displayed on the display unit 4 and the touch panel 5 (see FIG. 1). Then, the process proceeds to step S11.

[0046] Next, in step S11, the control unit 10 performs a second receiving step of receiving information that the user has selected one selection X-ray image D1 from the two selection X-ray images displayed on the display unit 4 and the touch panel 5. The detailed operation of the control unit 10 in step S11 is the same as the operation of the control unit 10 in step S5. Then, the process proceeds to step S12.

[0047] Next, in step S12, the control unit 10 accepts a selection as to whether or not the setting of the processing parameters for image processing has been completed. In step S12, if the user is not satisfied with the image quality of the selection X-ray image D1 selected in step S11 and wishes to further change the image quality of the X-ray image, the user operates the operation unit 6 to input to the control unit 10 that the setting of the processing parameters has not been completed. If the control unit 10 accepts that the setting of the adjustment parameters has not been completed, the control unit 10 returns to step S8 and repeats the processes of steps S8 to S11 again. Note that, if the control unit 10 returns to step S8, it extracts two types of selection parameters from the storage unit 7 so as to include selection parameters for generating a selection X-ray image D3 (see FIG. 11 ) that enhances the tendency of the visual recognition characteristics of the selection X-ray image selected in step S11.

[0048] Specifically, in step S11, the selection X-ray images C1 to C7 and D1 to D7 are generated so that their visibility characteristics change each time they are selected by the user, as shown in Fig. 11. For example, as shown in Fig. 11, if the user selects selection X-ray image D1, which has a strong tendency for visibility characteristics (high noise and high clarity) such that "blood vessels can be seen more clearly (high clarity)" and "noise is not suppressed (high noise)" compared to selection X-ray image C1, then selection X-ray image D3, which tends to have even more noise and higher clarity than selection X-ray image D1, and selection X-ray image D2, which has clarity and noise levels intermediate between those of selection X-ray image D1 and selection X-ray image D3, are generated. 11 shows that when a selection X-ray image D2, which tends to have less noise and less definition than selection X-ray image D1, is selected, a selection X-ray image D4, which tends to have less noise and less definition than selection X-ray image D2, and a selection X-ray image D5, which tends to have more noise and greater definition than selection X-ray image D2, are generated. The same applies to the other selection X-ray images.

[0049] Furthermore, the control unit 10 extracts a plurality of selection parameters from the storage unit 7 so that the amount of change in the selection parameters, which are changed to enhance the tendency of the visibility characteristics of the X-ray images, becomes smaller each time the selection of one selection X-ray image by the user is accepted. That is, the amount of change in the parameters that changes when a selection X-ray image D3 is generated based on the selection of selection X-ray image D1 is smaller than the amount of change in the parameters that changes when a selection X-ray image D7 is generated based on the selection of selection X-ray image D3.

[0050] In step S12, if the user is satisfied with the image quality of the selection X-ray image selected in step S11 and does not need to change the processing parameters any further, the user operates the operation unit 6 to input to the control unit 10 that the processing parameter setting has been completed. When the control unit 10 receives that the processing parameter setting has been completed, the control unit 10 proceeds to the processing of step S13. In this embodiment, for example, a case will be described in which the processing parameter setting has been completed in step S11 with the selection X-ray image D5 being selected last.

[0051] Next, in step S13, the control unit 10 updates and sets the observation parameters P1 selected in step S1. Specifically, the control unit 10 updates and sets a combination of both the adjustment parameters for generating the selection X-ray image A4 last selected in step S5 and the processing parameters for generating the selection X-ray image D5 last selected in step S11 as new observation parameters P1, and stores the combination in the storage unit 7. In this way, the control unit 10 updates and sets the observation parameters P1 for generating X-ray images that meet the user's preferences.

[0052] (Effects of this embodiment) The above embodiment can provide the following effects.

[0053] In the X-ray imaging apparatus 100 according to a first aspect and the control method for the X-ray imaging apparatus 100 according to a second aspect of the present embodiment, the control unit 10 generates a plurality of selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7, each having different visibility characteristics, corresponding to a plurality of selection parameters extracted from the storage unit 7, accepts a user's selection of one selection X-ray image D5 from among the plurality of selection X-ray images, sets the selection parameters used to generate the selection X-ray image D5 selected by the user as observation parameters P1 for generating an observation X-ray image I1, and stores the selection parameters in the storage unit 7. As a result, based on the user's selection of one selection X-ray image D5 from among the selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7 generated by the control unit 10, the control unit 10 can set observation parameters P1 to be used when performing X-ray imaging on a subject or the like, and store and save the observation parameters P1 in the storage unit 7. As a result, the observation parameters P1 for changing the image quality of the X-ray image can be set without having to ask a service technician to make the adjustment.

[0054] Furthermore, the X-ray imaging apparatus 100 and the control method for the X-ray imaging apparatus 100 according to the above embodiment are configured as follows, thereby providing the following additional effects.

[0055] In the X-ray imaging apparatus 100 and the control method for the X-ray imaging apparatus 100 according to the above embodiment, the control unit 10 is configured to, after accepting the user's selection of one selection X-ray image A1, further generate a plurality of selection X-ray images A2 and A3 having visibility characteristics different from the visibility characteristics of the selection X-ray image A1 selected by the user, before setting the observation parameters P1. This allows the user to check a plurality of selection X-ray images A2 and A3 whose visibility characteristics have been further modified relative to the selected selection X-ray image A1. As a result, the user can increase the number of selection X-ray images to refer to when setting the observation parameters P1 to P3, thereby obtaining X-ray images with visibility characteristics that better suit the user's preferences.

[0056] In the X-ray imaging apparatus 100 and the control method for the X-ray imaging apparatus 100 according to the above embodiment, the control unit 10 is configured to: accept a user's selection of one selection X-ray image and generate multiple selection X-ray images A1-A7 and B1-B7 twice; accept a user's selection of one selection X-ray image A4 and generate multiple selection X-ray images C1-C7 and D1-D7 twice; then accept a selection termination operation from the user; and set the selection parameters used to generate the selection X-ray image D5 last selected by the user as the observation parameters P1. This allows the user to select a selection X-ray image with image quality closer to their preference by repeatedly checking multiple selection X-ray images with modified visibility characteristics from the multiple selection X-ray images they previously selected. As a result, the user can set the observation parameters P1-P3 closer to their preference.

[0057] In the X-ray imaging apparatus 100 and the control method for the X-ray imaging apparatus 100 according to the above embodiment, the control unit 10 accepts a user's selection of one observation parameter P1 from among the observation parameters P1 to P3 stored in the storage unit 7, and generates a plurality of selection X-ray images A1 and B1 having visibility characteristics different from the visibility characteristics of the observation X-ray image I1 corresponding to the one observation parameter P1. The control unit 10 is also configured to update and set the selection parameters used in generating one selection X-ray image D5 selected by the user from among the plurality of selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7 as the observation parameters P1. This makes it easier to set the desired observation parameters P1 than if the observation parameters P1 were set from scratch.

[0058] In the X-ray imaging apparatus 100 and the control method for the X-ray imaging apparatus 100 according to the above embodiment, the selection parameters and observation parameters P1 to P3 include adjustment parameters related to the adjustment of the X-ray irradiator 21 and the X-ray detector 22. This makes it possible to generate selection X-ray images A1 to A7 and B1 to B7 in which adjustment parameters related to the X-ray irradiator 21 and the X-ray detector 22 that cannot be operated by the user have been changed. As a result, the user can set observation parameter P1 in which adjustment parameters that cannot be operated by the user have been changed.

[0059] In the X-ray imaging apparatus 100 and the control method for the X-ray imaging apparatus 100 according to the above embodiment, the selection parameters and observation parameters P1 to P3 include processing parameters for performing image processing on X-ray images. This makes it possible to generate selection X-ray images C1 to C7 and D1 to D7 in which processing parameters related to complex image processing have been changed. As a result, the user can easily set the observation parameter P1 in which the processing parameters have been changed, without having to individually change various image processing parameters.

[0060] In the X-ray imaging apparatus 100 and the control method for the X-ray imaging apparatus 100 according to the above embodiment, the control unit 10 is configured to extract multiple selection parameters from the storage unit 7 each time the control unit 10 receives a selection of one of the selection X-ray images A1-A7, B1-B7, C1-C7, and D1-D7 by the user, so as to include selection parameters that enhance the degree of the tendency of the visual characteristics of the selection X-ray images A1-A7, B1-B7, C1-C7, and D1-D7. This generates selection X-ray images A1-A7, B1-B7, C1-C7, and D1-D7, which enhance the tendency of the visual characteristics preferred by the user. As a result, the user's desired observation parameter P1 can be easily set.

[0061] In the X-ray imaging apparatus 100 and the control method for the X-ray imaging apparatus 100 according to the above embodiment, the control unit 10 is configured to extract multiple selection parameters from the storage unit 7 so that the amount of change in the selection parameters, which are changed to enhance the degree of tendency of the visibility characteristics of the X-ray images, decreases each time the user selects one of the selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7. This makes it possible to generate selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7 with fine-tuned visibility characteristics to suit the user's preferences. As a result, the user's desired observation parameter P1 can be set more precisely and appropriately.

[0062] In the X-ray imaging apparatus 100 and the control method for the X-ray imaging apparatus 100 according to the above embodiment, the tendency of the visibility characteristics includes a tendency of high noise and high definition, and a tendency of low noise and low definition. This allows the user to select one of the selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7 that has been generated based on the visibility characteristic tendency that suits the user's preference from the two types of visibility characteristic tendencies relating to the level of noise and the level of definition.

[0063] The X-ray imaging apparatus 100 and the control method for the X-ray imaging apparatus 100 of the above embodiment further include a display unit 4 that displays X-ray images, and the display unit 4 is configured to display a plurality of selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7 side by side. This allows the user to simultaneously view the plurality of selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7 displayed on a single screen, and therefore allows the user to easily select a preferred selection X-ray image A1 to A7, B1 to B7, C1 to C7, or D1 to D7.

[0064] In the X-ray imaging apparatus 100 and the control method for the X-ray imaging apparatus 100 according to the above embodiment, the storage unit 7 is configured to store a plurality of selection parameters, each of which is configured from a plurality of parameters that change the visibility characteristics of an X-ray image. As a result, even when the image quality of an X-ray image is affected by a complex interplay of a plurality of parameters, the user can easily set the observation parameter P1, which is configured from a plurality of parameters, by selecting the selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7 that have been generated based on the selection parameter, which is configured from a plurality of parameters.

[0065] [Modifications] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the description of the above-mentioned embodiments, and further includes all modifications (modifications) within the meaning and scope of the claims.

[0066] For example, in the above embodiment, the imaging unit 2 includes one C-arm 23, and performs angiography to acquire X-ray images. However, the present invention is not limited to this. In the present invention, the imaging unit 2 is not particularly limited as long as it is configured to be able to perform X-ray imaging, and may include two C-arms 23 or no C-arm 23. Furthermore, the X-ray image is not limited to an image of blood vessels, and may be, for example, an X-ray image of a phantom F or a patient's bones.

[0067] In the above embodiment, the display unit 4 is fixed to the ceiling of the imaging room, but the present invention is not limited to this. In the present invention, the display unit 4 may be provided integrally with the control unit 10, for example, or may be provided movably.

[0068] In the above embodiment, the storage unit 7 is disposed near the control unit 10, but the present invention is not limited to this. In the present invention, the storage unit 7 may be configured to be provided at a location remote from the X-ray imaging device 100 by being connected to the X-ray imaging device 100 via a network.

[0069] Furthermore, in the above embodiment, an example was shown in which the control unit 10, after accepting the user's selection of one selection X-ray image A1, further generates a plurality of selection X-ray images A2 and A3 having visibility characteristics different from the visibility characteristics of the one selection X-ray image selected by the user before setting the observation parameters P1, but the present invention is not limited to this. In the present invention, it is not necessary to generate another selection X-ray image after the user selects one selection X-ray image A1.

[0070] In the above embodiment, the control unit 10 repeats the process of accepting the user's selection of one selection X-ray image and generating multiple selection X-ray images A1 to A7 and B1 to B7 twice, and then accepts the user's selection completion operation after repeating the process of accepting the user's selection of one selection X-ray image and generating multiple selection X-ray images C1 to C7 and D1 to D7 twice, and sets the selection parameters used to generate the selection X-ray image D5 last selected by the user as the observation parameters P1. However, the present invention is not limited to this. The present invention may also be configured to accept the user's selection of one selection X-ray image A1 and set the selection parameters directly as the observation parameters P1. Furthermore, the control unit 10 may repeat the process of accepting the user's selection of one selection X-ray image and generating multiple selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7 three or more times.

[0071] In the above embodiment, the control unit 10 accepts the user's selection of one observation parameter P1 from among the observation parameters P1 to P3 stored in the storage unit 7 and generates multiple selection X-ray images A1 and B1 having visibility characteristics different from the visibility characteristics of the observation X-ray image I1 corresponding to the selected observation parameter P1. Although the control unit 10 updates and sets the selection parameters used to generate one selection X-ray image D5 selected by the user from among the selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7 as the observation parameters P1, the present invention is not limited to this. The present invention may also be configured to generate selection X-ray images based on standard selection parameters preset in the device without using the observation parameters P1. In this case, the process is configured to start from step S2 of the flow in FIG. 9 . Alternatively, the observation parameters P1 may be assigned a different name and set as different observation parameters without being updated.

[0072] In the above embodiment, the selection parameters and observation parameters P1 to P3 include adjustment parameters related to the adjustment of the X-ray irradiator 21 and the X-ray detector 22, but the present invention is not limited to this. For example, the present invention may be configured to set the observation parameters P1 to P3 so as to change only the processing parameters related to image processing. In this case, the process is configured to start from step S8 in the flowchart of FIG. 9.

[0073] In the above embodiment, the selection parameters and observation parameters P1 to P3 include processing parameters for performing image processing on an X-ray image, but the present invention is not limited to this. In the present invention, for example, the observation parameters P1 to P3 may be registered so as to change only the adjustment parameters related to the adjustment of the X-ray irradiator 21 and the X-ray detector 22. In this case, the process proceeds to step S13 after step S6 in the flowchart of FIG. 9.

[0074] Furthermore, in the above embodiment, an example was shown in which the control unit 10 extracts a plurality of selection parameters from the storage unit 7 so as to include selection parameters that strengthen the tendency of the visibility characteristics of the selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7 each time the control unit 10 accepts the selection of one of the selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7 by the user, but the present invention is not limited to this. For example, the present invention may be configured such that, when the user makes the first selection, a selection X-ray image in which the tendency of the visibility characteristics is strengthened to the maximum is generated, and thereafter, each time the selection of a selection X-ray image is accepted, selection parameters are extracted that gradually weaken the tendency of the visibility characteristics.

[0075] Furthermore, in the above embodiment, an example was shown in which the control unit 10 extracts from the storage unit 7 a plurality of selection parameters so that the amount of change in the selection parameters, which are changed to enhance the tendency of the visibility characteristics of the X-ray images, decreases each time the selection of one of the selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7 by the user is accepted, but the present invention is not limited to this. In the present invention, the control unit 10 may be configured to extract from the storage unit 7 a plurality of selection parameters so that the amount of change in the selection parameters, which are changed to enhance the tendency of the visibility characteristics of the X-ray images, increases each time the selection of one of the selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7 by the user is accepted.

[0076] In the above embodiment, the display unit 4 for displaying X-ray images is further provided, and the display unit 4 displays a plurality of selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7 in an array, but the present invention is not limited to this. In the present invention, the display unit 4 may be configured to display a plurality of selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7 in order.

[0077] In the above embodiment, the storage unit 7 stores a plurality of selection parameters, each of which is configured with a plurality of parameters that change the visibility characteristics of an X-ray image. However, the present invention is not limited to this. In the present invention, the storage unit 7 may be configured to store a plurality of selection parameters, including a selection parameter that is configured with a single parameter.

[0078] In the above embodiment, the selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7 and the observation X-ray image I1 have two visibility characteristics that are in a trade-off relationship, namely, "noise suppression" and "clear visibility of blood vessels." However, the present invention is not limited to this. In the present invention, the visibility characteristics of the selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7 and the observation X-ray image I1 are not particularly limited as long as they affect the image quality of the X-ray images. Furthermore, the selection parameters used to generate the selection X-ray images A1 to A7, B1 to B7, C1 to C7, and D1 to D7 and the observation X-ray image I1 may be configured so that the generated X-ray images have three or more visibility characteristics, or may be configured to have only one visibility characteristic and parameters for generating an X-ray image that has a trade-off relationship with the X-ray exposure dose.

[0079] In the above embodiment, the control unit 10 is configured to generate two selection X-ray images A1 and B1, each having different visibility characteristics, corresponding to two selection parameters extracted from the storage unit 7. However, the present invention is not limited to this. In the present invention, three or more selection X-ray images, each having different visibility characteristics, corresponding to three or more selection parameters may be generated from the storage unit 7. In this case, the three or more generated selection X-ray images are displayed simultaneously on the display unit 4.

[0080] In the above embodiment, the adjustment parameters for the X-ray irradiator 21 and the X-ray detector 22 are set, followed by the setting of the processing parameters for performing image processing on the X-ray image. However, the present invention is not limited to this. After the adjustment parameters have been set (steps S1 to S6 and S13), the present invention may be configured to update the observation parameters P1 by performing a process of changing the processing parameters as necessary (steps S8 to S13) after X-ray imaging of an actual patient other than the phantom F.

[0081] Aspects It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0082] an X-ray imaging device comprising: an X-ray irradiation unit that irradiates an object with X-rays; an X-ray detection unit that detects the X-rays irradiated from the X-ray irradiation unit; a control unit that generates an X-ray image based on an X-ray detection signal detected by the X-ray detection unit; and a memory unit that stores a plurality of selection parameters for adjusting visibility characteristics of the X-ray image, wherein the control unit is configured to: generate a plurality of selection X-ray images, each having different visibility characteristics, corresponding to the plurality of selection parameters extracted from the memory unit; accept selection of one of the plurality of selection X-ray images by a user; set the selection parameters used to generate the one selection X-ray image selected by the user as observation parameters for generating an X-ray image for observation; and store the selection parameters in the memory unit.

[0083] (Item 2) The X-ray imaging device according to Item 1, wherein the control unit is configured to, after accepting the selection of the one selection X-ray image by the user, and before setting the observation parameters, further generate a plurality of selection X-ray images having visibility characteristics different from the visibility characteristics of the one selection X-ray image selected by the user.

[0084] (Item 3) The X-ray imaging device according to Item 2, wherein the control unit is configured to: repeat the process of accepting the selection of the one selection X-ray image by the user and generating the multiple selection X-ray images a predetermined number of times; accept a selection completion operation by the user; and set the selection parameters used in generating the selection X-ray image last selected by the user as the observation parameters.

[0085] (Item 4) The X-ray imaging device according to Item 1, wherein the control unit is configured to: accept selection of one of the observation parameters by the user from among the observation parameters stored in the storage unit; generate the plurality of selection X-ray images having visibility characteristics different from the visibility characteristics of the observation X-ray image corresponding to the one observation parameter; and update and set the selection parameter used in generating the one selection X-ray image selected by the user from among the plurality of selection X-ray images as the observation parameter.

[0086] (Item 5) The X-ray imaging apparatus according to Item 1, wherein the selection parameters and the observation parameters include parameters relating to adjustment of the X-ray irradiation unit and the X-ray detection unit.

[0087] (Item 6) The X-ray imaging apparatus according to item 1, wherein the selection parameters and the observation parameters include parameters for performing image processing on the X-ray image.

[0088] (Item 7) The X-ray imaging device according to Item 3, wherein the control unit is configured to extract a plurality of selection parameters from the storage unit each time the control unit receives the selection of one selection X-ray image by the user, so as to include the selection parameters that enhance the tendency of the visual characteristics of the selection X-ray image.

[0089] (Item 8) The X-ray imaging device described in Item 7, wherein the control unit is configured to extract the multiple selection parameters from the memory unit so that the amount of change in the selection parameters, which are changed to enhance the tendency of the visual characteristics of the X-ray image, becomes smaller each time the selection of one selection X-ray image by the user is accepted.

[0090] (Item 9) The X-ray imaging apparatus according to Item 7, wherein the trends in the visibility characteristics include a trend toward high noise and high definition, and a trend toward low noise and low definition.

[0091] (Item 10) The X-ray imaging apparatus according to Item 1, further comprising a display unit that displays the X-ray images, wherein the display unit is configured to display the plurality of selection X-ray images side by side.

[0092] (Item 11) The X-ray imaging apparatus according to Item 1, wherein the storage unit is configured to store the plurality of selection parameters, each of which is configured by a plurality of parameters that change the visibility characteristics of the X-ray image.

[0093] (Item 12) A control method for an X-ray imaging device including a control unit that generates an X-ray image based on a detection signal of X-rays irradiated onto an imaging subject, and a memory unit that stores a plurality of selection parameters for adjusting visibility characteristics of the X-ray image, the control unit comprising: an extraction / generation step in which the control unit generates a plurality of selection X-ray images, each having different visibility characteristics corresponding to the plurality of selection parameters extracted from the memory unit; an acceptance step in which the control unit accepts a user's selection of one of the plurality of selection X-ray images; a setting step in which the control unit sets the selection parameters used to generate the selected one selection X-ray image as observation parameters for generating a new observation X-ray image; and a storage step in which the storage unit stores the observation parameters.

[0094] REFERENCE SIGNS LIST 1 Top plate 2 Imaging unit 3 Moving unit 4 Display unit 5 Touch panel 6 Operation unit 7 Storage unit 10 Control unit 13 Image generation unit 21 X-ray irradiation unit 22 X-ray detection unit 100 X-ray imaging device A1 to A7, B1 to B7, C1 to C7, D1 to D7 X-ray image for selection F Phantom I1 X-ray image for observation P1 to P3 Observation parameters

Claims

1. An X-ray imaging device comprising: an X-ray irradiation unit which irradiates X-rays onto an object to be imaged; an X-ray detection unit which detects the X-rays irradiated from the X-ray irradiation unit; a control unit which generates an X-ray image based on an X-ray detection signal detected by the X-ray detection unit; and a memory unit which stores a plurality of selection parameters for adjusting visibility characteristics of the X-ray image, wherein the control unit is configured to: generate a plurality of selection X-ray images, each having different visibility characteristics corresponding to the plurality of selection parameters extracted from the memory unit; accept a selection of one of the plurality of selection X-ray images by a user; set the selection parameters used in generating the one selection X-ray image selected by the user as observation parameters for generating an observation X-ray image; and store the selection parameters in the memory unit.

2. The X-ray imaging device of claim 1, wherein the control unit is configured to, after accepting the selection of the one selection X-ray image by the user and before setting the observation parameters, further generate a plurality of the selection X-ray images having visual characteristics different from the visual characteristics of the one selection X-ray image selected by the user.

3. The X-ray imaging device of claim 2, wherein the control unit is configured to: repeat the process of accepting the user's selection of the one selection X-ray image and generating the multiple selection X-ray images a predetermined number of times; accept an operation by the user to end selection; and set the selection parameters used in generating the selection X-ray image finally selected by the user as the observation parameters.

4. The X-ray imaging device of claim 1, wherein the control unit is configured to: accept selection by the user of one of the observation parameters stored in the memory unit; generate the plurality of selection X-ray images having visual characteristics different from the visual characteristics of the observation X-ray image corresponding to the one observation parameter; and update and set the selection parameter used in generating the one selection X-ray image selected by the user from the plurality of selection X-ray images as the observation parameter.

5. The X-ray imaging device according to claim 1, wherein the selection parameters and the observation parameters include parameters relating to adjustment of the X-ray irradiation unit and the X-ray detection unit.

6. The X-ray imaging apparatus according to claim 1, wherein the selection parameters and the observation parameters include parameters for performing image processing on the X-ray image.

7. The X-ray imaging device of claim 3, wherein the control unit is configured to extract a plurality of selection parameters from the memory unit each time the control unit accepts selection of one selection X-ray image by the user, so as to include a selection parameter that enhances the degree of tendency of the visual characteristics of the selection X-ray image.

8. The X-ray imaging device described in claim 7, wherein the control unit is configured to extract the multiple selection parameters from the memory unit so that the amount of change in the selection parameters, which are modified to enhance the degree of tendency of the visual characteristics of the X-ray image, becomes smaller each time the selection of one selection X-ray image by the user is accepted.

9. The X-ray imaging device according to claim 7, wherein the trends in the visibility characteristics include a trend toward greater noise and greater sharpness, and a trend toward less noise and less sharpness.

10. The X-ray imaging device according to claim 1, further comprising a display unit for displaying the X-ray images, the display unit being configured to display the plurality of selection X-ray images side by side.

11. The X-ray imaging device according to claim 1, wherein said storage unit is configured to store said plurality of selection parameters, each of which is composed of a plurality of parameters that change the visual characteristics of said X-ray image.

12. A control method for an X-ray imaging device comprising a control unit which generates an X-ray image based on a detection signal of X-rays irradiated to an object to be imaged, and a memory unit which stores a plurality of selection parameters for adjusting the visibility characteristics of the X-ray image, the control unit comprising: an extraction and generation step in which the control unit generates a plurality of selection X-ray images, each having different visibility characteristics corresponding to the plurality of selection parameters extracted from the memory unit; an acceptance step in which the control unit accepts a user's selection of one of the plurality of selection X-ray images; a setting step in which the control unit sets the selection parameters used in generating the selected one selection X-ray image as observation parameters for generating a new observation X-ray image; and a storage step in which the storage unit stores the observation parameters.

Images