X-ray diagnostic apparatus

Abstract

The present invention relates to an X-ray diagnostic apparatus that reduces the manufacturing cost of a quality filter. The X-ray diagnostic apparatus according to an embodiment includes: an X-ray tube having a plurality of focal spots and irradiating X-rays from each of the focal spots; a quality filter that changes the radiation quality of the X-rays irradiated from the plurality of focal spots; and a moving mechanism that moves the quality filter along the direction in which the plurality of focal spots are arranged.

Description

Technical Field

[0001] The embodiments disclosed in this specification and the accompanying drawings relate to an X-ray diagnostic apparatus. Background Art

[0002] For tomosynthesis imaging used in mammography in X-ray diagnosis, an imaging method is widely known in which an imaging image of tomosynthesis is obtained while moving an X-ray tube. However, when collecting data of an imaging image while continuously moving the X-ray tube, the imaging image may be blurred due to the movement of the focal point of the X-ray tube.

[0003] Therefore, an imaging method is being developed in which an X-ray tube having a plurality of fixed focal points is used, whereby an imaging image can be collected even without continuously moving the X-ray tube. Thus, X-ray imaging can be performed using X-rays irradiated from a fixed X-ray tube, and thus the generation of the above-described blur of the imaging image can be eliminated.

[0004] However, for an X-ray tube having a plurality of focal points, as with conventional X-ray tubes, in order to change the radiation quality of X-rays, a beam quality filter for adjusting the energy of photons is required. However, since X-rays are irradiated from all of the plurality of focal points, a beam quality filter having a relatively large area that covers the entire plurality of focal points must be mounted. However, as a raw material for manufacturing the beam quality filter, expensive materials such as molybdenum, rhodium, and silver are used, and an increase in the area of the beam quality filter using expensive raw materials increases the manufacturing cost of the X-ray diagnostic apparatus.

[0005] Patent Document 1: Japanese Patent Laid-Open No. 11-108857

[0006] Patent Document 2: Japanese Patent Laid-Open No. 2008-12206

[0007] Patent Document 3: Japanese Patent Laid-Open No. 2013-5854

[0008] Non-Patent Document: NIH Public Access, Proc SPIE. 2010 January 1; 7622:76225M. doi:10.1117 / 12.844586. Summary of the Invention

[0009] The problem to be solved by the embodiments disclosed in this specification and the accompanying drawings is to provide an X-ray diagnostic apparatus that reduces the manufacturing cost of a beam quality filter. However, the problem to be solved by the embodiments disclosed in this specification and the accompanying drawings is not limited to the above problem. It is also possible to define other problems corresponding to the respective effects brought about by the respective configurations shown in the embodiments described later as other problems.

[0010] The X-ray diagnostic apparatus according to the embodiment includes: an X-ray tube having a plurality of focal spots and irradiating X-rays from each focal spot; a beam quality filter for changing the radiation quality of the X-rays irradiated from the plurality of focal spots; and a moving mechanism for moving the beam quality filter along the direction in which the plurality of focal spots are arranged. Description of the Drawings

[0011] Figure 1 It is a block diagram showing the configuration of the X-ray diagnostic apparatus according to the first embodiment.

[0012] Figure 2 It shows Figure 1 An example of the configuration of the beam quality filter moving mechanism of the X-ray diagnostic apparatus shown.

[0013] Figure 3 It is a flowchart showing the processing content of the X-ray imaging process performed by the X-ray diagnostic apparatus according to the first embodiment.

[0014] Figure 4 It is a block diagram showing the configuration of the X-ray diagnostic apparatus according to the second embodiment.

[0015] Figure 5 It is a flowchart showing the processing content of the X-ray imaging process performed by the X-ray diagnostic apparatus according to the second embodiment.

[0016] Figure 6 It shows Figure 4 An example of the irradiation schedule generated by the X-ray tube selection control unit of the X-ray diagnostic apparatus shown.

[0017] Figure 7 It is a block diagram showing the configuration of the X-ray diagnostic apparatus according to the third embodiment.

[0018] Figure 8 It shows Figure 7 An example of the configuration of the beam quality filter moving mechanism of the X-ray diagnostic apparatus shown.

[0019] Figure 9 It shows Figure 7 A block diagram of a modified example of the configuration of the beam quality filter moving mechanism of the X-ray diagnostic apparatus shown.

[0020] Figure 10 It is a flowchart showing the processing content of the X-ray imaging process performed by the X-ray diagnostic apparatus according to the third embodiment.

[0021] Description of Reference Numerals

[0022] 1: X-ray diagnostic apparatus; 10: multi-focus X-ray tube; 20: quality filter moving mechanism; 22: support portion; 24: track; 26: drive mechanism; 30: quality filter; 32: sub-quality filter; 34: sub-quality filter; 40: compression plate; 50: X-ray detector; 60: control unit; 70: user interface; 80: high voltage generation device; 90: X-ray tube selection control unit; 100: quality filter position control unit; 102: quality filter speed calculation unit; 110: image storage device; 120: image processing device; 120: image processing device; 130: image display device; 140: timer; P: subject. Detailed implementation manners

[0023] Hereinafter, embodiments of the X-ray diagnostic apparatus will be described in detail with reference to the accompanying drawings. In the following description, components having substantially the same functions and configurations are given the same reference numerals, and repeated descriptions will be made only when necessary.

[0024] [First Embodiment]

[0025] First, based on Figure 1 the configuration of the X-ray diagnostic apparatus 1 of the first embodiment will be described. As shown in this Figure 1 figure, the X-ray diagnostic apparatus 1 is an apparatus capable of performing X-ray imaging of a subject P, and is configured to include a multi-focus X-ray tube 10, a quality filter moving mechanism 20, a quality filter 30, a compression plate 40, an X-ray detector 50, a control unit 60, a user interface 70, a high voltage generation device 80, an X-ray tube selection control unit 90, a quality filter position control unit 100, an image storage device 110, an image processing device 120, and an image display device 130.

[0026] The multi-focus X-ray tube 10 is an X-ray tube having a plurality of focal points and irradiating X-rays from each focal point. Here, the multi-focus X-ray tube will be briefly described. In an apparatus that uses X-rays for imaging to obtain an X-ray image, for example, there are apparatuses that perform tomosynthesis imaging in mammography, apparatuses that perform long-size imaging to achieve X-ray imaging of a relatively wide and long area, and the like. In such an apparatus for X-ray imaging, in order to obtain an X-ray image, the X-ray tube is moved to image the X-ray image of the region required for diagnosis. However, since the X-ray tube is moved, the image shakes and the imaging takes time. On the other hand, by using an X-ray tube having a plurality of focal points, X-rays can be independently irradiated from each focal point, and tomosynthesis imaging and long-size imaging can be achieved without moving the X-ray tube.

[0027] Similar to a normal single-focus X-ray tube, the multi-focus X-ray tube 10 has a filament of the cathode and a target metal of the anode within a vacuum enclosure. The multi-focus X-ray tube 10 is supplied with a current corresponding to the tube voltage and tube current from a high-voltage generating device 80. The tube voltage refers to the acceleration voltage of the electron beam within the multi-focus X-ray tube 10, and the higher the value of the tube voltage, the higher the transmittance of the X-ray. The tube current refers to the current value of the electron beam generated from the filament.

[0028] In addition, the filament is formed of, for example, carbon nanotubes. When a current corresponding to the tube current is supplied from the high-voltage generating device 80, the filament generates thermoelectrons. That is, the number of thermoelectrons generated per unit time is the tube current. The target metal is, for example, tungsten or the like. A tube voltage supplied from the high-voltage generating device 80 is applied between these cathode and anode, and an electric field is generated between the cathode and anode. The thermoelectrons accelerated by this electric field collide with the target metal of the anode, and X-rays are generated from the target metal. As the tube voltage increases, the wavelength peak of the X-ray shifts toward the short-wavelength side, and the energy of the X-ray also increases.

[0029] Furthermore, in the multi-focus X-ray tube 10 of the present embodiment, in order to form multiple focal points, for example, multiple cathodes are provided. Then, when a tube current is supplied to any one of the multiple cathodes, thermoelectrons are irradiated from the cathode to which the tube current is supplied, collide with the anode as the target metal, and X-rays are generated. In the case of this configuration, by appropriately selecting the cathode to which the tube current is supplied, the focal point at which the X-ray is irradiated can be selected.

[0030] Alternatively, in order to form multiple focal points, in the multi-focus X-ray tube 10, for example, after changing the orbit of the thermoelectrons irradiated from the cathode using a deflector, they collide with the anode as the target metal to generate X-rays. The deflector changes the orbit of the thermoelectrons by changing the electric field and magnetic field generated by the deflector. In the case of this configuration, similar to a normal single-focus X-ray tube, as long as a pair of cathode and anode are provided, by controlling the intensity and orientation of the electric field and magnetic field generated by the deflector, the position of the focal point at which the X-ray is irradiated can be selected.

[0031] In Figure 1 is shown a multi-focus X-ray tube 10 having five focal points #1 to #5. That is, the focal points #1, #2... #5 are arranged in order from the left side to the right side of the figure. Regarding the number of focal points of the multi-focus X-ray tube 10, depending on the purpose and characteristics of the X-ray diagnostic apparatus 1, it is not limited to five focal points, and a multi-focus X-ray tube 10 having less than five focal points or more than five focal points can also be used. In addition, in Figure 1 the arrangement direction of the focal points is linear, but a linear arrangement is not necessarily required, and the multiple focal points can also be arranged in an arc shape or a curved shape, etc., and there is no particular limitation on the number and arrangement method of the focal points of the multi-focus X-ray tube.

[0032] The line quality filter moving mechanism 20 is a mechanism that moves the line quality filter 30 in the direction in which the multiple focal points of the multi-focal X-ray tube 10 are arranged, and is configured to be able to move the line quality filter 30 to positions corresponding to the multiple focal points of the multi-focal X-ray tube 10, that is, the filtering positions. In other words, the line quality filter moving mechanism 20 is configured to be able to move the line quality filter 30 to the filtering positions where the X-rays irradiated from the multiple focal points intersect. In the present embodiment, for example, since the X-ray irradiation direction of the multi-focal X-ray tube 10 is downward, the line quality filter moving mechanism 20 is provided below the multi-focal X-ray tube 10.

[0033] Figure 2 is a block diagram showing an example of the configuration of the line quality filter moving mechanism 20 of the present embodiment. As shown in this Figure 2 figure, the line quality filter moving machine 20 includes, for example: a support portion 22 on which the line quality filter 30 is mounted; a track 24 laid along the direction in which the multiple focal points of the multi-focal X-ray tube 10 are arranged, for moving the support portion 22 on which the line quality filter 30 is mounted; and a drive mechanism 26 such as a motor that provides power for moving the support portion 22.

[0034] The track 24 is arranged along the multiple focal points of the multi-focal X-ray tube 10. That is, the track 24 is laid so that the line quality filter 30 can be positioned at the filtering positions corresponding to the respective focal points by the movement of the line quality filter moving mechanism 20 on the track 24. The number of tracks 24 laid can be one, two, or more.

[0035] For example, when the multiple focal points of the multi-focal X-ray tube 10 are linearly arranged, the track 24 is also linearly arranged along the multiple focal points. In addition, for example, when the multiple focal points of the multi-focal X-ray tube 10 are arranged in an arc shape, the track 24 is also arranged in an arc shape along the multiple focal points. In the present embodiment, the track 24 is an example of a guiding mechanism that guides the support portion 22 on which the line quality filter 30 is mounted. This guiding mechanism can also be composed of, for example, a groove that guides the support portion 22, a guiding device using magnetism, etc.

[0036] In addition, the drive mechanism 26 includes, for example: an interface for transmitting and receiving signals between the line quality filter position control unit 100 and other components of the X-ray diagnostic apparatus 1 other than the line quality filter moving mechanism 20; and a control circuit for managing the movement of the line quality filter moving mechanism 20. The drive mechanism 26 can be composed of, for example, an electric rotary motor, an electric linear motor, or an engine. In addition, the drive mechanism 26 can also be composed of a self-weight moving device that moves downward along an inclined plane by its own weight and stops at a specified position.

[0037] In this embodiment, the multi-focus X-ray tube 10 has five focal points #1 to #5. Therefore, the beam quality filter moving mechanism 20, for example, moves the beam quality filter 30 to five filtering positions corresponding to the focal points for irradiating X-rays while moving in the Figure 2 arrow direction in the figure. In addition, the beam quality filter moving mechanism 20 itself can move in the Figure 2 arrow direction in the figure and can also move in the direction opposite to the arrow. However, when irradiating X-rays from each focal point of the multi-focus X-ray tube 10, it can move in one direction and continuously irradiate X-rays from the focal points #1 to #5 respectively.

[0038] Again, as shown in Figure 1 the figure, the beam quality filter 30 is a filter provided on the support portion 22 of the above-mentioned Figure 2 beam quality filter moving mechanism 20. Similar to a normal single-focus X-ray tube, the beam quality filter 30 is used to change the radiation quality of the X-rays irradiated by the multi-focus X-ray tube 10 and adjust the energy of the photons, that is, the intensity of the X-rays. Due to the presence of this beam quality filter 30, it is also possible to reduce the radiation dose of the subject P. For example, molybdenum (Mo), rhodium (Rh), silver (Ag), etc. are used as raw materials for manufacturing the beam quality filter 30.

[0039] In addition, when taking an X-ray image using a multi-focus X-ray tube, the X-rays from each of the multiple focal points are irradiated independently. Therefore, the beam quality filter 30 requires an area corresponding to the irradiation range of the X-rays irradiated from one focal point. In other words, in this embodiment, as the size of the beam quality filter 30, an area sufficient to function as a filter for the X-rays irradiated from one focal point is required. However, since X-rays are not irradiated from other focal points simultaneously, it can be defined as a size such that it does not need to function as a filter for the X-rays irradiated from other focal points.

[0040] That is, regarding the area of the beam quality filter 30, according to necessary conditions such as the beam diameter of the X-rays irradiated from each focal point of the multi-focus X-ray tube 10 and the distance between the multi-focus X-ray tube 10 and the beam quality filter 30, an area corresponding to the irradiation range of the X-rays irradiated from each focal point is determined. And in order to reduce the non-uniformity of the captured X-ray image, it is necessary to make the radiation quality of the X-rays irradiated from each focal point after passing through the beam quality filter 30 constant, and it is necessary to make the entire beam quality filter 30 composed of a thickness and density as uniform as possible.

[0041] The compression plate 40 is provided above the X-ray detector 50, that is, in the direction where the multi-focus X-ray tube 10 is located. For example, the compression plate 40 is arranged to perform compression and fixation for X-ray imaging of the subject P, that is, the breast, placed on the X-ray detector 50. Therefore, the compression plate 40 is equipped with a mechanism for enabling up and down movement, etc. In addition, since the compression plate 40 is located above the subject P, it is made of a material that can be penetrated by X-rays, and is, for example, made of a transparent acrylic plate or the like that also takes visibility into account.

[0042] In addition, in Figure 1 , an example is shown where the X-ray diagnostic apparatus 1 is a device for performing tomosynthesis imaging by mammography. However, depending on the type of the X-ray diagnostic apparatus 1, the compression plate 40 is not necessarily an essential component. For example, in a device for performing X-ray imaging for chest X-ray diagnosis, etc., when the X-ray diagnostic apparatus 1 is a device for performing X-ray imaging other than the breast, the compression plate 40 is not necessarily required.

[0043] The X-ray detector 50 places the subject P and detects an X-ray image of the X-rays that have passed through the subject P in units of pixels according to the X-rays irradiated from the multi-focus X-ray tube 10, and outputs an image signal proportional to the detected X-ray amount to the image processing apparatus 120. The X-ray detector 50 is, for example, composed of a flat panel detector (FPD: Flat Panel Detector) or the like for detecting X-rays irradiated onto the detection surface.

[0044] The control unit 60 performs overall control of the X-ray diagnostic apparatus 1 of the present invention. Specifically, the control unit 60 issues necessary instructions to each component of the X-ray diagnostic apparatus 1 in order to implement various instructions input by the user via the user interface 70. The control unit 60 is, for example, composed of a storage medium that stores programs required for performing various examinations by the X-ray diagnostic apparatus 1, a processor for executing these programs, and the like.

[0045] The user interface 70 is equipped with a mechanism for the user to perform operations required for taking an X-ray image of the subject P using the X-ray diagnostic apparatus 1. For example, when a radiation switch is provided on the user interface 70, the user can indicate the start of X-ray imaging of irradiating X-rays from the multi-focus X-ray tube 10 by pressing the radiation switch. In addition, when the user interface 70 is composed of a touch panel, the user can input instructions required for X-ray diagnosis to the X-ray diagnostic apparatus 1 by touching the touch panel as needed. In the present embodiment, in addition to the radiation switch and the touch panel, the user interface 70 can also be composed of any appropriate input mechanisms such as a display, a switch button, a keyboard, a mouse, a trackball, etc.

[0046] The high-voltage generating device 80 supplies a current corresponding to the tube voltage and the tube current to the multi-focus X-ray tube 10, and is composed of, for example, a transformer and a rectifier. The transformer boosts the alternating current supplied from the AC power source according to the set tube voltage, and supplies the boosted alternating voltage to the rectifier. The rectifier rectifies the alternating voltage supplied from the transformer, and outputs a pulsating voltage having only a positive component as the tube voltage.

[0047] The X-ray tube selection control unit 90 selects the focus (e.g., Figure 1 focus #1 in Figure 1 ) among the multiple foci of the multi-focus X-ray tube 10 that should irradiate X-rays, and controls to apply the tube voltage set by the high-voltage generating device 80. In addition, the X-ray tube selection control unit 90 sends a signal including information on the selected focus (e.g.,

[0048] focus #1 in Figure 1 ) among the multiple foci of the multi-focus X-ray tube 10 that should irradiate X-rays to the beam quality filter position control unit 100.

[0049] The object of the X-ray diagnostic apparatus 1 according to the present embodiment is to reduce the manufacturing cost of the X-ray diagnostic apparatus 1 by reducing the area of the quality filter 30 for converting the radiation quality of the X-rays irradiated from each focal point of the multi-focal X-ray tube 10. In other words, the area of the quality filter 30 according to the present embodiment cannot cover the irradiation range of the X-rays irradiated from all the focal points of the plurality of focal points. Therefore, the quality filter position control unit 100 performs position control to move the quality filter 30 so that the quality filter 30 is located at a filtering position corresponding to the focal point of the irradiated X-rays when irradiating the X-rays. Thus, in order to physically move the quality filter 30 by the quality filter moving mechanism 20, the quality filter position control unit 100 outputs commands and information required to move the quality filter moving mechanism 20 to the quality filter moving mechanism 20.

[0050] In the present embodiment, for example, in the control unit 60 or the quality filter position control unit 100, a movement position correspondence table in which each focal point of the multi-focal X-ray tube 10 is associated with the position of the quality filter moving mechanism 20 is provided, so that the movement position of the quality filter moving mechanism 20 can be determined. The quality filter position control unit 100 determines the irradiation position of the X-rays irradiated from each focal point based on this movement position correspondence table, moves the quality filter moving mechanism 20, and moves the quality filter 30 to a filtering position corresponding to the focal point of the irradiated X-rays.

[0051] The image storage device 110 stores an X-ray image, which is an image of the X-rays that have passed through the subject P, according to the irradiation of the X-rays from each focal point of the multi-focal X-ray tube 10. In the present embodiment, a series of multiple X-ray images that have undergone the necessary image processing in the image processing device 120 are stored in the image storage device 110 in association with tomosynthesis imaging. The image storage device 110 includes, for example, a storage circuit. The storage circuit is constituted by a readable storage medium such as a magnetic storage medium, an optical storage medium, or a semiconductor memory.

[0052] The image processing device 120 generates an X-ray image based on the image signal of the X-rays output from the X-ray detector 50. The image processing device 120 includes, for example, an AD conversion circuit, an image correction unit, etc. The AD conversion circuit converts the image signal of the X-rays, which is an analog signal output from the X-ray detector 50, into a digital image signal. The image correction unit performs necessary correction processing on each pixel of the X-ray detector 50 for the digital image signal connected to the AD conversion circuit, and generates a corrected X-ray image. The generated X-ray image is, for example, saved in the image storage device 110 or displayed by the image display device 130. In addition, the AD conversion circuit can also be provided in the X-ray detector 50. In this case, the image processing device 120 obtains the digital image signal from the X-ray detector 50.

[0053] In addition, in the present embodiment, the X-ray diagnostic apparatus 1 performs a process of reconstructing images of a plurality of X-ray images captured of one subject P in order to capture an X-ray image based on the tomosynthesis imaging method. That is, the X-ray images captured at the respective plurality of focal points of the multi-focus X-ray tube 10 are read out from the image storage device 110 and reconstructed to generate one X-ray image.

[0054] The image processing device 120 includes, for example, a storage circuit, a processing circuit, etc. As described above, the storage circuit includes a readable storage medium such as a magnetic storage medium, an optical storage medium, or a semiconductor memory. In addition, the storage circuit stores various processing functions executed by the processing circuit in the form of a program executable by a computer. The processing circuit is a processor or the like that realizes each processing function corresponding to each program by reading out and executing the program from the storage circuit. As the image processing executed by the image processing device 120, there are, for example, processes related to image reconstruction such as Filtered Back Projection, ML-EM, OS-EM, processes related to image adjustment such as gray-scale processing, frequency processing, and dynamic range compression, etc.

[0055] The image display device 130 displays the X-ray image that has undergone image processing in the image processing device 120 as a display image. For example, the image display device 130 is composed of a liquid crystal display device, a CRT (Cathode Ray Tube) monitor, etc. for displaying the X-ray image to the user, but the display method of the X-ray image is not particularly limited.

[0056] The above is the description of the configuration of the X-ray diagnostic apparatus 1 according to the first embodiment. Hereinafter, a series of processes related to the X-ray image capturing process of the X-ray diagnostic apparatus 1 according to the first embodiment will be described.

[0057] Figure 3This is a flowchart showing a series of processes for capturing an X-ray image of the first embodiment. This X-ray imaging process is performed for the following purpose: in the case of mammography, multiple X-ray images related to the subject P are captured according to the positioning of the subject P, and the captured multiple X-ray images are subjected to a reconstruction process and displayed, thereby enabling X-ray image diagnosis using tomosynthesis imaging.

[0058] The user positions the subject P for X-ray diagnosis in the X-ray diagnostic apparatus 1 (step S100). In this embodiment, as Figure 1 shown, the subject P, i.e., the breast, is placed on the X-ray detector 50, and the subject P is compressed and fixed in a position suitable for X-ray diagnosis using the compression plate 40.

[0059] Next, the user inputs an instruction to start imaging via the user interface 70 (step S102). For example, when a radiation switch is provided as the user interface 70, the user can input an instruction to start imaging by pressing this radiation switch. By inputting an instruction to start imaging, various operations required for X-ray imaging are thereby started.

[0060] Next, the control unit 60 sends a signal to the high-voltage generation device 80 and the X-ray tube selection control unit 90 (step S104). The high-voltage generation device 80, when receiving the signal, sets the tube voltage, tube current, and filament current that have been preset. The values of the preset tube voltage, tube current, and filament current are, for example, values input by the user via the user interface 70. Alternatively, the values of the preset tube voltage, tube current, and filament current are values calculated based on information such as the examination type specified by the input from the user interface 70 and the size of the subject P. The X-ray tube selection control unit 90, when receiving the signal, controls the multi-focus X-ray tube 10 so as to irradiate X-rays from the focus selected by this signal. In this embodiment, the multi-focus X-ray tube 10 has five foci #1 to #5. Therefore, first, the X-ray tube selection control unit 90 controls the multi-focus X-ray tube 10, for example, to irradiate X-rays starting from focus #1.

[0061] While performing step S104, the control unit 60 sends a signal to the beam quality filter position control unit 100 (step S106). When receiving the signal, the beam quality filter position control unit 100 controls the beam quality filter moving mechanism 20 so that the beam quality filter 30 is located at the filter position corresponding to the focal point selected by this signal. For example, based on a movement position correspondence table that correlates each focal point of the multi-focal X-ray tube 10 with the position of the beam quality filter moving mechanism 20, the beam quality filter position control unit 100 sends information on the position to which the beam quality filter 30 should move, that is, information on the filter position, to the beam quality filter moving mechanism 20. Based on the received information on the filter position, the beam quality filter moving mechanism 20 moves the beam quality filter 30. For example, as described above, when the selected focal point is focal point #1, the beam quality filter position control unit 100 controls the beam quality filter moving mechanism 20 so that the beam quality filter 30 stops at the filter position where it intersects the X-rays irradiated from the focal point #1 of the multi-focal X-ray tube 10.

[0062] Next, the control unit 60 irradiates X-rays from the X-ray tube, and irradiates X-rays from the focal point selected by the X-ray tube selection control unit 90 (step S108). For example, as described above, when the selected focal point is focal point #1, the values of the tube voltage, tube current, and filament current set by the high voltage generation device 80 are applied to the focal point #1 selected by the X-ray tube selection control unit 90, and thus X-rays are irradiated from the focal point #1 of the multi-focal X-ray tube 10. At this time, the beam quality filter 30 stops and stands by at the filter position where it can filter the X-rays irradiated from the focal point #1. Therefore, the X-rays irradiated from the focal point #1 of the multi-focal X-ray tube 10 pass through the beam quality filter 30, change the radiation quality to the desired X-ray spectrum for X-ray imaging of the subject P, and pass through the compression plate 40 and the subject P and reach the X-ray detector 50.

[0063] Next, the control unit 60 outputs the X-ray image signal in units of pixels of the X-rays that have passed through the compression plate 40 and the subject P and have been detected by the X-ray detector 50 to the image processing device 120 to generate one X-ray image (step S110). The generated X-ray image is saved in the image storage device 110. Thus, the imaging of one X-ray image at one focal point is completed. For example, when the initially selected focal point is focal point #1, the imaging of the X-ray image based on the X-rays irradiated from the focal point #1 of the multi-focal X-ray tube 10 is completed.

[0064] Next, the control unit 60 determines whether X-ray images have been captured at all the focal points of the multiple focal points of the multi-focal X-ray tube 10 (step S112). In the present embodiment, the multi-focal X-ray tube 10 has five focal points #1 to #5. Therefore, for example, when capturing an X-ray image starting from focal point #1, the capture is performed in the order of focal point #2, focal point #3... focal point #5. Therefore, in step S112, it is determined whether the capture has ended at all these five focal points.

[0065] When the capture has not ended at all the focal points (step S112: No), the control unit 60 moves the focal point for irradiating X-rays to the next focal point (step S114) and repeats from the above step S104. That is, an X-ray image is captured at the next focal point.

[0066] On the other hand, when it is determined that the capture of X-ray images has ended at all the focal points (step S112: Yes), the control unit 60 performs image processing based on multiple X-ray images of X-rays irradiated from each focal point of the multi-focal X-ray tube 10 (step S116). That is, the image processing device 120 of the X-ray diagnostic apparatus 1 reads out multiple X-ray images stored in the image storage device 110, performs reconstruction processing and image adjustment processing based on the multiple X-ray images, and generates one X-ray image.

[0067] Next, the control unit 60 displays the X-ray image that has undergone the image processing in step S114 on the image display device 130 so that the user can perform X-ray diagnosis of the subject P (step S118). In addition, the X-ray diagnostic apparatus 1 may also store the X-ray image generated in step S114 in the image storage device 110 as needed. Through this step S118, this X-ray imaging process ends.

[0068] As described above, in the X-ray diagnostic apparatus of the present embodiment, when capturing an X-ray image using the multi-focal X-ray tube 10, when moving the quality filter 30 having an area corresponding to the irradiation range of the X-rays irradiated from each focal point using the quality filter moving mechanism 20 and irradiating X-rays from multiple focal points respectively, the quality filter 30 is positioned at the filtering position corresponding to that focal point. Therefore, the area of the quality filter 30 can be minimized as much as possible, and the manufacturing cost of the quality filter 30 can be reduced. That is, there is no need to prepare a quality filter with an area that covers all multiple focal points, and the amount of expensive raw materials required for manufacturing the quality filter can be reduced.

[0069] [Second Embodiment]

[0070] In the first embodiment described above, the driving of the line quality filter moving mechanism 20 is temporarily stopped at the filtering position, and X-rays are irradiated from the multi-focus X-ray tube 10 while the line quality filter 30 is stopped from moving. On the other hand, in the second embodiment, the difference from the first embodiment is that X-rays are irradiated from the multi-focus X-ray tube 10 while the line quality filter moving mechanism 20 is driven and the line quality filter 30 moves without stopping. Hereinafter, the parts different from the first embodiment will be described.

[0071] Figure 4 is a block diagram for explaining the configuration of the X-ray diagnostic apparatus 1 of the second embodiment. As shown in this Figure 4 figure, similar to the first embodiment described above, the X-ray diagnostic apparatus 1 is an apparatus capable of performing X-ray imaging of a subject P, but the difference is that it includes a line quality filter speed calculation unit 102 instead of the line quality filtering position control unit 100, and additionally includes a timer 140.

[0072] The line quality filter speed calculation unit 102 calculates the speed at which the line quality filter moving mechanism 20 moves the line quality filter 30. In the second embodiment, when irradiating X-rays from each focus of the multi-focus X-ray tube 10, the line quality filter moving mechanism 20 does not stop the line quality filter 30 but continues to move it. That is, the line quality filter 30 does not stop and X-rays are irradiated from each focus of the multi-focus X-ray tube 10. Therefore, when irradiating X-rays from each focus, the line quality filter 30 must be located at the filtering position where it intersects the irradiated X-rays. If the line quality filter 30 is not located at the filtering position, the irradiated X-rays will not pass through the line quality filter 30, so the radiation quality of the X-rays cannot be changed. Therefore, the line quality filter speed calculation unit 102 calculates the speed at which the line quality filter moving mechanism 20 moves the line quality filter 30 so that when irradiating X-rays from each focus of the multi-focus X-ray tube 10 to the line quality filter 30, the line quality filter 30 passes through the filtering position corresponding to the focus irradiating the X-rays. In the present embodiment, the line quality filter speed calculation unit 102 and the control unit 60 constitute a control unit for controlling the line quality filter moving mechanism 20.

[0073] The timer 140 provides the time information required by the X-ray diagnostic apparatus 1 of the present embodiment. Based on the provided time information, the X-ray tube selection control unit 90 controls such that at a desired time, the high voltage generation apparatus 80 applies a tube voltage or the like to the multi-focus X-ray tube 10. Further, based on the provided time information, the beam quality filter speed calculation unit 102 calculates the moving speed of the beam quality filter moving mechanism 20. That is, when irradiating X-rays from each focus of the multi-focus X-ray tube 10, in order for the beam quality filter 30 to pass through the filtering position corresponding to the focus, the X-ray tube selection control unit 90 related to the control of X-ray irradiation and the beam quality filter speed calculation unit 102 related to the control of the beam quality filter moving mechanism 20 need to perform control synchronously. The timer 140 is implemented, for example, by using the stopwatch function, clock function, etc. provided in the control computer.

[0074] The above is the description of the parts different from those of the X-ray diagnostic apparatus 1 of the first embodiment in the configuration of the X-ray diagnostic apparatus 1 of the second embodiment. Hereinafter, a series of processes related to the imaging process of the X-ray image of the X-ray diagnostic apparatus 1 of the second embodiment will be described.

[0075] Figure 5 It is a diagram showing a flowchart representing a series of processes of the X-ray imaging of the second embodiment, and is a diagram corresponding to the above-described first embodiment Figure 3 corresponding diagram.

[0076] The operations from after the positioning of the subject P (step S100) to until the user inputs an instruction to start imaging (step S102) are the same as those of the first embodiment.

[0077] After this step S102, the control unit 60 sends signals to the high voltage generation apparatus 80 and the X-ray tube selection control unit 90 (step S204). When receiving the signal, the high voltage generation apparatus 80 sets the preset tube voltage, tube current, and filament current. When receiving the signal, the X-ray tube selection control unit 90 generates an irradiation schedule table that correlates the irradiation of X-rays from the nth focus of the multi-focus X-ray tube 10 after a few seconds from when the timer 140 starts measuring the time.

[0078] Figure 6 It is a diagram showing an example of the irradiation schedule table generated by the X-ray tube selection control unit 90 of the present embodiment. As shown in this Figure 6 figure, the irradiation schedule table of the present embodiment holds the focus numbers #1 to #5 that sequentially assign numbers to a plurality of foci, and the elapsed time designating the timing of irradiating X-rays with the focus number. That is, for each focus, the time at which the elapsed time measured by the timer 140 becomes a few seconds is determined for X-ray irradiation.

[0079] Again, as Figure 5 shown, the control unit 60 sends a signal to the timer 140 to start measuring the time (step S206). In addition, at the same time, the X-ray tube selection control unit 90 controls the timer 140 so that the time of the timer 140 corresponds to the prepared irradiation schedule. When the time of the irradiation schedule is reached, the tube voltage, tube current, and filament current preset by the high voltage generating device 80 are applied to the multi-focus X-ray tube 10 (step S208).

[0080] In addition, at the same time, the control unit 60 inputs the irradiation schedule created by the X-ray tube selection control unit 90 to the beam quality filter speed calculation unit 102. The beam quality filter speed calculation unit 102 calculates the speed of the beam quality filter moving mechanism 20 based on the input irradiation schedule so that when X-rays are irradiated from each focus of the multi-focus X-ray tube 10, the beam quality filter 30 can pass through the filtering position corresponding to that focus (step S210). Then, the beam quality filter speed calculation unit 102 controls the beam quality filter moving mechanism 20 so that the beam quality filter 30 moves at the calculated speed.

[0081] When the settings of the beam quality filter moving mechanism 20, the high voltage generating device 80, the X-ray tube selection control unit 90, and the timer 140 are completed, X-rays are irradiated from the respective foci, and X-ray images are sequentially captured (step S212). That is, based on the time information of the timer 140 and the irradiation schedule that establishes the correspondence between the number of seconds after the start measurement time of the timer 140 and from which focus the X-rays are irradiated, the X-ray tube selection control unit 90 selects the focus and irradiates X-rays at the specified elapsed time. On the other hand, the beam quality filter speed calculation unit 102 controls the beam quality filter moving mechanism 20 to move at the calculated speed, so that the beam quality filter 30 passes through the filtering position corresponding to the focus where the X-rays are irradiated at the specified elapsed time. For example, in the present embodiment, through this step S212, five X-ray images captured by irradiating X-rays from foci #1 to #5 are sequentially obtained. The plurality of captured X-ray images are stored in the image storage device 110.

[0082] Next, image processing of the plurality of X-ray images based on the X-rays irradiated from the respective foci of the multi-focus X-ray tube 10 is performed (step S116) and displayed on the image display device 130 (step S320). The processing of steps S116 and S118 is the same as that of the first embodiment.

[0083] As described above, according to the X-ray diagnostic apparatus 1 of the second embodiment, it is possible to successively obtain a plurality of X-ray images of the subject P without stopping the movement of the quality filter 30. Similar to the first embodiment, it is possible to reduce the manufacturing cost of the quality filter 30 and save the time when the quality filter 30 stops. Therefore, it is possible to obtain a plurality of X-ray images more quickly.

[0084] In addition, since X-rays are irradiated from each focus of the multi-focus X-ray tube 10 while the quality filter 30 is moving, even if there are some unevennesses in the density, thickness, etc. of the raw materials (e.g., Rh, Ag, etc.) constituting the quality filter 30, the X-rays transmitted through the quality filter 30 can be homogenized, and the unevenness in the X-ray image can be reduced. And during the manufacturing process, there is no need to improve the uniformity of the quality filter 30, so the manufacturing cost of the quality filter 30 can be further reduced.

[0085] In addition, in the present embodiment, it is assumed that the quality filter moving mechanism 20 moves at a constant speed calculated by the quality filter speed calculation unit 102, but the quality filter moving mechanism 20 may also decelerate at the filtering position. That is, it may be that when approaching the filtering position corresponding to the focus where X-rays are irradiated, the quality filter moving mechanism 20 decelerates without stopping, making it easier to align the timing of irradiating X-rays from the focus.

[0086] [Third Embodiment]

[0087] In the above first embodiment and second embodiment, one type of quality filter 30 is mounted on the quality filter moving mechanism 20, but in the third embodiment, the quality filter 30 is composed of a plurality of sub-quality filters with different raw material types, and it is possible to change the radiation quality of the X-rays according to the characteristics of the subject P, or to image the subject P with a plurality of X-rays of different radiation qualities in one imaging operation. Hereinafter, the parts different from the above first embodiment will be described, but this embodiment can also be applied to the X-ray diagnostic apparatus 1 of the second embodiment.

[0088] Figure 7 It is a block diagram for explaining the configuration of the X-ray diagnostic apparatus 1 of the third embodiment. As shown in this Figure 7 As shown, similar to the above first embodiment, the X-ray diagnostic apparatus 1 is an apparatus capable of performing X-ray imaging of the subject P, but the difference is that the quality filter 30 includes two sub-quality filters 32 and 34.

[0089] Figure 8 It is a block diagram showing an example of the configuration of the quality filter moving mechanism 20 of the present embodiment. As shown in this Figure 8As shown, in the beam quality filter moving mechanism 20 of the present embodiment, the beam quality filter 30 includes a sub-beam quality filter 32 and a sub-beam quality filter 34, both of which are provided on the support portion 22 of the beam quality filter moving mechanism 20, and the beam quality filter moving mechanism 20 is provided below (in the X-ray irradiation direction) of the multi-focus X-ray tube 10. These two sub-beam quality filters 32, 34 are used to adjust the photon energy of the X-rays irradiated by the multi-focus X-ray tube 10 and to adjust the radiation quality of the X-rays.

[0090] There is no particular limitation on the raw materials constituting the sub-beam quality filter 32 and the sub-beam quality filter 34. However, in the present embodiment, the sub-beam quality filter 32 and the sub-beam quality filter 34 are respectively constituted by different raw materials. In other words, in the sub-beam quality filter 32 and the sub-beam quality filter 34, the physical properties for changing the radiation quality of the X-rays are different. For example, when the sub-beam quality filter 32 is made of rhodium (Rh), the sub-beam quality filter 34 is made of a raw material other than Rh such as silver (Ag). Thus, the X-rays irradiated from each focus of the multi-focus X-ray tube 10 are converted into X-rays having different radiation qualities depending on whether they pass through the sub-beam quality filter 32 or the sub-beam quality filter 34, and two types of X-rays with different line amounts and characteristics can be utilized.

[0091] In this Figure 8 case, the two sub-beam quality filters 32, 34 are combined and provided on one support portion 22. Therefore, when the motor of the drive mechanism 26 is driven, the sub-beam quality filters 32, 34 move together as a unit. However, it is also possible to separate the two sub-beam quality filters 32, 34 without setting them on one support portion 22.

[0092] Figure 9 is a block diagram showing an example of the configuration of the beam quality filter moving mechanism 20 when the two sub-beam quality filters 32, 34 are separated. In this Figure 9 example, two support portions 22 are arranged on the track 24, and these two support portions 22 are connected to each other. Then, the sub-beam quality filter 32 is provided on one support portion 22, and the sub-beam quality filter 34 is provided on the other support portion 22. Since the two support portions 22 are connected, when the motor of the drive mechanism 26 is driven, the sub-beam quality filters 32, 34 move together in a separated state.

[0093] By preparing a plurality of sub-beam quality filters with different physical characteristics, it is possible to adjust the X-ray dose according to the characteristics of the subject P. For example, in the present embodiment, when the thickness of the right breast of a patient is different from that of the left breast and the thickness of the right breast is thicker, an X-ray image of the right breast can be taken using the sub-beam quality filter 32 with a higher X-ray transmittance, and an X-ray image of the left breast can be taken using the sub-beam quality filter 34 with a lower X-ray transmittance. In this case, when the user executes the X-ray imaging process via the user interface 70, an instruction input is made to indicate which beam quality filter among the plurality of sub-beam quality filters is to be used for imaging. That is, when taking an X-ray image of the right breast, the user places the right breast of the patient on the X-ray detector 50 and makes an instruction input via the user interface 70 to irradiate X-rays from the focal points #1 to #5 using the sub-beam quality filter 32 for X-ray imaging. Then, when taking an X-ray image of the left breast, the user places the left breast of the patient on the X-ray detector 50 and makes an instruction input via the user interface 70 to irradiate X-rays from the focal points #1 to #5 using the sub-beam quality filter 34 for X-ray imaging.

[0094] Alternatively, in the X-ray diagnostic apparatus 1 of the present embodiment, by the user making an instruction input for starting imaging once, dual-energy imaging of imaging a subject P with a plurality of different energies can be achieved. That is, for example, by taking an X-ray image of irradiating X-rays at the focal point #1 using the sub-beam quality filter 32, and then taking an X-ray image of irradiating X-rays at the same focal point #1 using the sub-beam quality filter 34, it is possible to take two images with X-rays of different energies at the focal point #1. By sequentially performing this imaging at the focal points #2 to #5, dual-energy imaging can also be performed.

[0095] After multiplying the X-ray images taken at the same position by appropriate coefficients and then performing subtraction, in addition to the simple X-ray image, a soft tissue image (excluding the bone image) and a bone tissue image can be generated. Thus, for example, in a simple X-ray image related to the chest, ribs and the like that can be separated into obstructive shadows can be made easier to read.

[0096] In addition, in the present embodiment, the configuration of the X-ray diagnostic apparatus 1 has been described by taking the case where the number of sub-beam quality filters included in the beam quality filter 30 is two as an example, but the number of sub-beam quality filters included in the beam quality filter 30 does not have to be two, and any number of multiple sub-beam quality filters such as three or four can also be included.

[0097] The above is the description of the parts different from the configuration of the X-ray diagnostic apparatus 1 of the first embodiment in the configuration of the X-ray diagnostic apparatus 1 of the third embodiment. Hereinafter, a series of processes related to the imaging process of the X-ray image of the X-ray diagnostic apparatus 1 of the third embodiment will be described.

[0098] As described above, in the case of performing X-ray imaging using any one of the plurality of sub-line quality filters 32 and 34 included in the line quality filter 30, when the user performs the X-ray imaging process, an instruction input is made as to which sub-line quality filter 32 or 34 is to be used for X-ray imaging. For example, in step S102 of the above-described first embodiment, Figure 3 the user inputs an instruction to start imaging to the X-ray diagnostic apparatus 1 via the user interface 70. However, at this time, an instruction input is also made as to which of the sub-line quality filters 32 and 34 is to be used for X-ray imaging. For example, when the user selects the sub-line quality filter 32, the X-ray diagnostic apparatus 1 uses this sub-line quality filter 32 as the line quality filter and irradiates X-rays from the focal points #1 to #5 to capture an X-ray image.

[0099] Alternatively, it may be that, in Figure 3 step S103, when the user inputs an instruction to start imaging, the control unit 60 of the X-ray diagnostic apparatus 1 automatically detects the thickness of the subject P, and the X-ray diagnostic apparatus 1 determines whether to use the sub-line quality filter 32 or the sub-line quality filter 34 based on the detected thickness of the subject P. In this case, for example, by providing a sensor that detects the distance between the compression plate 40 and the X-ray detector 50, the thickness of the subject P is calculated based on the distance detected by this sensor.

[0100] In this manner, when the X-ray diagnostic apparatus 1 of the third embodiment is operated, except for the need to select the sub-line quality filter to be used during X-ray imaging, the X-ray imaging process in the X-ray diagnostic apparatus 1 is the same as that of the above-described first embodiment.

[0101] On the other hand, in the case of performing X-ray imaging using the plurality of sub-line quality filters 32 and 34 separately, the X-ray imaging process in the X-ray diagnostic apparatus 1 is different from the above-described embodiments. Figure 10 is a diagram showing a flowchart representing the processing content of the X-ray diagnostic apparatus 1 in this case. In this X-ray imaging process, so-called dual-energy imaging is achieved: at each of the focal points #1 to #5 of the multi-focus X-ray tube 10, X-ray imaging is performed using the sub-line quality filter 32 as the line quality filter, and X-ray imaging is performed using the sub-line quality filter 34 as the line quality filter. Hereinafter, the parts different from the above-described first embodiment will be described.

[0102] After the subject P is positioned (step S100), the operations until the user inputs an instruction to start imaging (step S102) are the same as those in the first embodiment. However, in the subsequent processing, the difference from the above-described first embodiment is that after X-ray imaging is performed using the sub-quality filter 32 as the first sub-quality filter, X-ray imaging is performed using the sub-quality filter 34 as the second sub-quality filter. That is, X-ray imaging is performed twice at one focal point.

[0103] The Figure 10 steps S304 to S310 in this Figure 3 correspond to the processing steps S104 to S110 in the above-described first embodiment. However, the difference is that in step S308, the sub-quality filter 32 as the first sub-quality filter is moved to the filtering position corresponding to the focal point where X-rays are irradiated, and X-rays are irradiated. That is, when the sub-quality filter 32 is in the filtering position, the multi-focal X-ray tube 10 irradiates X-rays from the focal point corresponding to this filtering position, thereby obtaining an X-ray image of X-rays based on the radiation quality according to the characteristics of the sub-quality filter 32.

[0104] In step S310, after the captured X-ray image is saved in the image storage device 110, the X-ray diagnostic apparatus 1 executes steps S312 to S318 in order to perform X-ray imaging using the sub-quality filter 34 as the second sub-quality filter. The steps S312 to S318 also correspond to the processing steps S104 to S110 in the above-described first embodiment. However, the difference is that in step S316, the second sub-quality filter 34 is moved to the filtering position corresponding to the focal point where X-rays are irradiated, and X-rays are irradiated. That is, when the sub-quality filter 34 is in the filtering position, the multi-focal X-ray tube 10 irradiates X-rays from the focal point corresponding to this filtering position, thereby obtaining an X-ray image of X-rays based on the radiation quality according to the characteristics of the sub-quality filter 34. Figure 3 Then, in step S320, the X-ray diagnostic apparatus 1 determines whether X-ray imaging has been performed at all the focal points of the multi-focal X-ray tube 10 (step S320). In the present embodiment, the multi-focal X-ray tube 10 has five focal points, focal point #1 to focal point #5, so it is determined whether two X-ray imaging operations have been completed in sequence from focal point #1 to focal point #5.

[0105] Then, in step S320, the X-ray diagnostic apparatus 1 determines whether X-ray images have been captured at all the focal points of the multi-focal X-ray tube 10 (step S320). In this embodiment, the multi-focal X-ray tube 10 has five focal points, focal point #1 to focal point #5, so it is determined whether two X-ray imaging operations have been completed in sequence from focal point #1 to focal point #5.

[0106] When the imaging of all the focal points has not been completed (step S320: No), after the X-ray diagnostic apparatus 1 moves the focal point that irradiates the X-ray to the next focal point (step S114), the processing is repeated from the above step S304. That is, the X-ray image is captured twice at the next focal point.

[0107] On the other hand, when it is determined that the imaging of the X-ray image has been completed for all the focal points (step S320: Yes), the X-ray diagnostic apparatus 1 performs image processing based on a plurality of X-ray images obtained by irradiating the X-rays from the respective focal points of the multi-focal X-ray tube 10 (step S322). That is, the X-ray diagnostic apparatus 1 reads out a plurality of X-ray images stored in the image storage device 110, performs reconstruction processing based on the plurality of X-ray images, and generates one X-ray image. At this time, although an X-ray image obtained by performing X-ray imaging using the sub-ray quality filter 32 and an X-ray image obtained by performing X-ray imaging using the sub-ray quality filter 34 are generated, since the intensity and radiation quality of the X-rays are different, a more detailed and diagnostic-appropriate single X-ray image can be generated by synthesizing the two images.

[0108] Next, the X-ray diagnostic apparatus 1 displays the X-ray image that has undergone the image processing of step S322 on the image display device 130 for the user to perform X-ray diagnosis of the subject P (step S324). In addition, the X-ray diagnostic apparatus 1 may also store the generated X-ray image in the image storage device 110 as needed. When displaying or storing these X-ray images, the finally generated single X-ray image may be displayed or stored, or the two X-ray images generated by performing imaging using the sub-ray quality filters 32 and 34 may be displayed or stored separately. Through this step S324, the X-ray imaging process ends.

[0109] As described above, according to the X-ray diagnostic apparatus 1 of the present embodiment, since the ray quality filter 30 includes a plurality of sub-ray quality filters made of different materials, X-ray imaging can be performed using X-rays of different radiation qualities. Therefore, in a case where the thickness of the subject P is relatively thick or the density is relatively high, for example, the sub-ray quality filter 32 that irradiates the subject P with X-rays of higher energy can be used for X-ray imaging, and in a case where the thickness of the subject P is relatively thin or the density is relatively low, for example, the sub-ray quality filter 34 that irradiates the subject P with X-rays of lower energy can be used for X-ray imaging.

[0110] Furthermore, according to the X-ray diagnosis apparatus 1 of the present embodiment, an X-ray image captured by low-energy X-rays and an X-ray image captured by high-energy X-rays can be acquired in a single imaging operation, so that, for example, dual-energy imaging can be realized by the X-ray diagnosis apparatus 1. Thus, an X-ray image with higher accuracy and suitable for diagnosis can be obtained.

[0111] In addition, in the above-mentioned first to third embodiments, the case of mammography in which the X-ray diagnostic device 1 performs X-ray photography of the breast is described as an example, but the X-ray diagnostic device 1 is not limited to mammography, and can be a device for performing X-ray photography of various parts. For example, the X-ray diagnostic device 1 can also be a long-length photography device that can perform X-ray photography of the entire leg or the entire chest. In this case, the compression plate 40 can be omitted. In addition, by positioning the legs and chest as the photography parts in front of the multi-focus X-ray tube 10 and irradiating X-rays from multiple focal points to perform X-ray photography, long-length X-ray photography can be performed without moving the X-ray tube. In addition, it is not limited to tomosynthesis photography and long-length photography. For example, the above-mentioned embodiment can also be applied to X-ray TV used in barium meal examination of the stomach, etc., and a general X-ray photography device.

[0112] In addition, in the first to third embodiments described above, the X-ray diagnostic apparatus 1 is described on the premise that the multi-focus X-ray tube 10 is fixed, but the multi-focus X-ray tube 10 does not necessarily need to be fixed. That is, the multi-focus X-ray tube 10 may be moved to perform X-ray imaging of a wider range than the subject P. In this case, in the above example, if imaging of irradiation of X-rays is completed at focal points #1 to #5, the multi-focus X-ray tube 10 may be moved and imaging of irradiation of X-rays may be performed again at focal points #1 to #5.

[0113] In this case, the moving direction of the multi-focus X-ray tube 10 may be a straight line or an arc. That is, when the multiple focal points in the multi-focus X-ray tube 10 are arranged in a straight line, the multi-focus X-ray tube 10 can be moved in a straight line along the direction in which the multiple focal points are arranged. On the other hand, when the multiple focal points in the multi-focus X-ray tube 10 are arranged in an arc shape, the multi-focus X-ray tube 10 can be moved in a manner of drawing an arc of the same radius on the extension line of the arc of the multiple focal points arranged in the arc shape.

[0114] In the above description, an example has been described in which the "processor" in the control unit 60 and the image processing device 120 reads out a program corresponding to each processing function from the storage circuit and executes it. However, the embodiment is not limited to this. The term "processor" means, for example, a circuit such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an application specific integrated circuit (ASIC), or a programmable logic device (for example, a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA)). When the processor is a CPU, for example, the processor reads out a program stored in the storage circuit and executes it, thereby implementing each processing function. On the other hand, when the processor is an ASIC, instead of storing the program in the storage circuit, the function is directly incorporated into the circuit of the processor as a logic circuit. Each processor of the present embodiment is not limited to the case where each processor is configured as a single circuit, and a plurality of independent circuits may be combined to form one processor and implement its processing function. It is also possible to Figure 1 combine a plurality of constituent elements in one processor to implement its processing function.

[0115] Several embodiments have been described, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the scope equivalent thereto.

Claims

1. An X-ray diagnostic apparatus, comprising: an X-ray tube having a plurality of focal spots and irradiating X-rays from each focal spot; a beam quality filter for changing the radiation quality of the X-rays irradiated from the plurality of focal spots; and a moving mechanism for moving the beam quality filter along the direction in which the plurality of focal spots are arranged. The beam quality filter adjusts the energy of the photons of the X-rays when the X-rays pass through the beam quality filter, thereby changing the radiation quality of the X-rays irradiated by the X-ray tube. The beam quality filter includes a plurality of sub-beam quality filters, and the types of raw materials of the plurality of sub-beam quality filters are different from each other. The moving mechanism moves the beam quality filter having the plurality of sub-beam quality filters while performing multiple X-ray imaging using different sub-beam quality filters at the same focal position.

2. The X-ray diagnostic apparatus according to claim 1, wherein, A control unit is provided, and the control unit controls the moving mechanism so that the beam quality filter is disposed at a filtering position corresponding to each of the plurality of focal spots.

3. The X-ray diagnostic apparatus according to claim 1, wherein, The moving mechanism includes: a guiding mechanism for guiding the beam quality filter along the direction in which the plurality of focal spots are arranged; and a supporting portion for supporting the beam quality filter and moving while being guided by the guiding mechanism.

4. The X-ray diagnostic apparatus according to claim 1, wherein, The beam quality filter has an area corresponding to the irradiation range of the X-rays irradiated from the plurality of focal spots respectively.

5. The X-ray diagnostic apparatus according to claim 2, wherein, The control unit controls the moving mechanism so that the plurality of sub-beam quality filters are respectively located at the filtering positions. When the plurality of sub-beam quality filters are respectively located at the filtering positions, the X-ray tube irradiates X-rays from the focal spot corresponding to the filtering position, thereby obtaining a plurality of X-ray images based on X-rays having different radiation qualities.

6. The X-ray diagnostic apparatus according to claim 1, wherein, The plurality of sub-beam quality filters are combined with each other and move integrally by the moving mechanism.

7. The X-ray diagnostic apparatus according to claim 1, wherein, The plurality of sub-beam quality filters are separated from each other and move together in a separated state by the moving mechanism.

8. The X-ray diagnostic apparatus according to any one of claims 1 to 7, wherein, The X-ray diagnostic apparatus is an X-ray apparatus capable of performing mammography, tomosynthesis imaging, an X-ray apparatus capable of performing long-size imaging, an X-ray TV, or an X-ray apparatus for general imaging.

9. The X-ray diagnostic apparatus according to any one of claims 1 to 7, wherein, The plurality of focal spots in the X-ray tube are arranged in a straight line or in an arc shape.

10. The X-ray diagnostic apparatus according to any one of claims 1 to 7, wherein, After the X-ray imaging of irradiating X-rays from the plurality of focal spots is completed, the X-ray tube is moved to perform X-ray imaging of irradiating X-rays from the plurality of focal spots again.

11. The X-ray diagnostic apparatus according to claim 2 or 5, wherein, The control unit controls the moving mechanism so that when X-rays are irradiated from any one of the plurality of focal spots, the beam quality filter stops and is located at the filtering position corresponding to the focal spot irradiating the X-rays.

12. The X-ray diagnostic apparatus according to claim 2 or 5, wherein, The control unit controls the moving mechanism so that when X-rays are irradiated from any one of the plurality of focal spots, the beam quality filter is located at the filtering position corresponding to the focal spot irradiating the X-rays without stopping the movement of the beam quality filter.

13. The X-ray diagnostic apparatus according to any one of claims 1 to 7, wherein, When X-rays are irradiated from the X-ray tube, the moving mechanism continuously moves the beam quality filter without stopping.

Images