JP7225006B2 - X-ray diagnostic equipment - Google Patents

Description

An embodiment of the invention relates to an X-ray diagnostic apparatus.

Conventionally, in fluoroscopy using a cardiovascular X-ray diagnostic apparatus, the operator interrupts and resumes fluoroscopy in accordance with the progress of a device such as a catheter. is performed on During one fluoroscopy, the tube voltage, tube current, and pulse width are controlled to appropriate values by feedback control even if the device is advanced. On the other hand, the size of the X-ray focal point (hereinafter referred to as the focal point size) is either kept at a fixed value, or manually changed by the operator when switching from the end of the previous fluoroscopy to the next fluoroscopy. is set with Along with this, for example, if the thickness of the subject has changed according to the progress of the device during the previous fluoroscopy, there is a possibility that the appropriate focus size will not be selected in the next fluoroscopy.

JP 2018-134417 A

The problem to be solved by the present invention is to automatically determine the appropriate focal spot size.

An X-ray diagnostic apparatus according to an embodiment includes an X-ray tube that generates X-rays, an X-ray detector that detects the X-rays emitted from the X-ray tube, the X-ray tube and the X-ray detector. and an X-ray condition determination unit for determining conditions for X-ray irradiation by the X-ray tube. The X-ray condition determining unit controls the operation unit after the first moving image capturing based on the output of the X-ray detector in the first moving image capturing performed in response to the operation of the operating unit. determining the size of the focal point of X-rays in the second moving image imaging performed according to the operation, and after the second moving image imaging based on the output of the X-ray detector in the second moving image imaging A focal size of X-rays is determined in a third moving image pickup that is performed in response to an operation on the operation unit.

FIG. 1 is a diagram illustrating the configuration of an X-ray diagnostic apparatus according to the first embodiment. FIG. 2 is a flowchart illustrating a processing procedure of fluoroscopy execution processing by the X-ray diagnostic apparatus according to the first embodiment. FIG. 3 is a flowchart illustrating a processing procedure of imaging condition setting processing by the X-ray diagnostic apparatus according to the first embodiment. FIG. 4 is a flowchart illustrating a processing procedure of imaging condition setting processing by the X-ray diagnostic apparatus according to the second embodiment. FIG. 5 is a flowchart illustrating a processing procedure of imaging condition setting processing by the X-ray diagnostic apparatus according to the third embodiment. FIG. 6 is a flowchart illustrating a processing procedure of imaging condition setting processing by the X-ray diagnostic apparatus according to the fourth embodiment.

Hereinafter, embodiments of the X-ray diagnostic apparatus will be described in detail with reference to the drawings. In the following description, components having substantially the same functions and configurations are denoted by the same reference numerals, and redundant description will be given only when necessary. An X-ray diagnostic apparatus according to the following embodiments may be, for example, a single modality apparatus or a composite modality apparatus such as an angio-CT apparatus.

(First embodiment)
FIG. 1 is a diagram showing a configuration example of an X-ray diagnostic apparatus 1 according to the first embodiment. As shown in FIG. 1, the X-ray diagnostic apparatus 1 includes an imaging device 10, a bed device 30, and a console device 40. As shown in FIG. The imaging device 10 includes a high voltage generator 11 , an X-ray generator 12 , an X-ray detector 13 , a C-arm 14 and a C-arm driving device 142 .

The high voltage generator 11 generates a high voltage to be applied between the anode and the cathode in order to accelerate thermal electrons generated from the cathode of the X-ray tube, and outputs the high voltage to the X-ray tube.

The X-ray generating unit 12 includes an X-ray tube for irradiating the subject P with X-rays, a plurality of filters (hereinafter referred to as additional filters) having a function of attenuating or reducing the dose of irradiated X-rays, and an X-ray diaphragm. It has

An x-ray tube is a vacuum tube that produces x-rays. An X-ray tube includes a tube, a filament (cathode) provided in the tube, and a tungsten anode. An X-ray tube accelerates thermal electrons emitted from a filament with a high voltage. The X-ray tube generates X-rays by colliding these accelerated electrons with a tungsten anode.

In this embodiment, two types of filaments are provided that differ in the size of the focal point (effective focal point) of the generated X-rays (hereinafter referred to as focal point size). The filament to be used is selected from among the two filaments according to the input by the operator through the input interface 43 (described later) or the setting by the processing circuit 44 (described later), and the filament to be used is driven by a driving device (not shown). can be switched. By switching the filament used, the focal size is switched between the small focus and the medium focus. A medium focus has a larger focal size than a small focus. A small focus is, for example, a value within the range of 0.2-0.4 mm. Medium focus is, for example, a value within the range of 0.5-0.7 mm. A small focus is an example of a first focus size. A medium focus is an example of a second focus size.

Note that in the present embodiment, two types of focus sizes, a small focus and a medium focus, can be set as focus sizes, but three or more focus sizes may be set. In this case, a number of filaments is provided corresponding to the number of focus sizes that can be set.

The additional filter is composed of a metal plate such as copper or aluminum. The additional filter is arranged between the X-ray tube and the X-ray diaphragm so that the long-wavelength component (soft X-ray) of the continuous spectrum X-rays generated by the X-ray generator 12 is reduced according to the thickness of the additional filter. to remove. The thickness of the additional filter is, for example, a value within the range of 0.1-5 mm. Additional filters are also called x-ray filters, filter plates, beam filters, quality filters, or beam spectrogram filters. The additional filter hardens the quality of the X-rays generated by the X-ray generator 12 by removing long wavelength components depending on the thickness. The additional filter can also remove X-ray energy components unnecessary for X-ray diagnosis. Thereby, the additional filter adjusts the radiation quality of the X-rays generated by the X-ray generator 12 .

In this embodiment, four additional filters (Filter A to Filter D) are provided. Filters A to D have different thicknesses. Therefore, filters A to D have different removal rates of soft X-rays (hereinafter referred to as X-ray reduction rates). A thick additional filter (thick additional filter) has a larger X-ray reduction rate than a thin additional filter (thick additional filter). The thickness of filter A is greater than the thickness of filter B, the thickness of filter B is greater than the thickness of filter C, and the thickness of filter C is greater than the thickness of filter D. Therefore, the X-ray reduction rate of filter A is greater than the X-ray reduction rate of filter B, the X-ray reduction rate of filter B is greater than the X-ray reduction rate of filter C, and the X-ray reduction rate of filter C is greater than the X-ray reduction rate of filter C. It is larger than the X-ray reduction rate of D.

The driving device applies an additional filter selected from among a plurality of additional filters to the X-ray tube and the X-ray diaphragm in accordance with an operator's input through an input interface 43, which will be described later, or a setting made by a processing circuit 44, which will be described later. insert in between. Further, the thickness of the additional filter is adjusted by switching the additional filter inserted between the X-ray tube and the X-ray diaphragm. That is, the driving device arranges at least one of the plurality of additional filters on the path from the focal point of the X-ray tube to the X-ray detector 13 . The driver is an example of a filter driver.

The X-ray diaphragm is positioned between the X-ray tube and the X-ray detector 13 and is composed of a lead plate as a metal plate. The X-ray diaphragm shields the X-rays outside the aperture area, narrows down the X-rays generated by the X-ray tube so that only the region of interest of the subject P is irradiated, and the X-ray irradiation area (X The size of the line field) (hereinafter referred to as the field size) is adjusted. For example, the X-ray diaphragm has four diaphragm blades, and by sliding these diaphragm blades, the size of the field of view is adjusted by adjusting the size of the X-ray shielded region to an arbitrary size. The diaphragm blades of the X-ray diaphragm are driven by a driving device (not shown) according to the region of interest input by the operator through the input interface 43 .

The X-ray detector 13 detects X-rays emitted from the X-ray tube and transmitted through the subject P. As such an X-ray detector 13, it is possible to use one that converts X-rays directly into charges, and one that converts X-rays into charges after converting them into light. It doesn't matter if it is. That is, the X-ray detector 13 includes, for example, a planar FPD (Flat Panel Detector) that converts X-rays that have passed through the subject P into charges and accumulates them, and a drive for reading out the charges accumulated in this FPD. and a gate driver for generating pulses. The size of the FPD is, for example, a value within the range of 8 to 16 inches. The FPD is configured by two-dimensionally arranging minute detection elements in the column direction and the line direction. Each detection element senses X-rays and includes a photoelectric film that generates charges according to the amount of incident X-rays, a charge storage capacitor that stores the charges generated in the photoelectric film, and a predetermined charge stored in the charge storage capacitor. It has a TFT (thin film transistor) that outputs at the timing of . Accumulated charges are sequentially read out by drive pulses supplied by the gate driver. The size of each detection element of the FPD (hereinafter referred to as FPD detection element) (hereinafter referred to as FPD element size) is, for example, a value within the range of 130 to 200 μm. However, the size of the FPD element is not limited to this example, and may be a minute size such as 76 μm square.

The C-arm 14 holds the X-ray generator 12 and the X-ray detector 13 so as to face each other with the subject P and the top plate 33 interposed therebetween, thereby performing X-ray imaging of the subject P on the top plate 33 . have a configuration that can be done. The C-arm 14 is slidably supported and rotatable around each of a plurality of rotation axes. The C-arm 14 is provided at appropriate locations with a plurality of power sources for achieving sliding and rotating motions. These power sources constitute the C-arm drive device 142 . The C-arm driving device 142 reads drive signals from the drive control function 443 and causes the C-arm 14 to slide, rotate, and linearly move.

The bed device 30 is a device for placing and moving the subject P, and includes a base 31 , a bed driving device 32 , a top plate 33 and a support frame 34 .

The base 31 is a housing that is installed on the floor and supports the support frame 34 so as to be movable in the vertical direction (Z direction).

The bed driving device 32 is a motor or actuator that is housed in the housing of the bed device 30 and moves the table 33 on which the subject P is placed in the longitudinal direction (Y direction) of the table 33 . The bed drive device 32 reads the drive signal from the drive control function 443 and moves the tabletop 33 horizontally or vertically with respect to the floor surface. By moving the C-arm 14 or the top board 33, the positional relationship of the imaging axis with respect to the subject P changes. Note that the bed driving device 32 may move the support frame 34 in the longitudinal direction of the top plate 33 in addition to the top plate 33 .

The top plate 33 is a plate provided on the upper surface of the support frame 34 and on which the subject P is placed.

The support frame 34 is provided above the base 31 and supports the top plate 33 so as to be slidable along its longitudinal direction.

In the bed apparatus 30, the top plate 33 may be movable with respect to the support frame 34, or the top plate 33 and the support frame 34 may be movable together with respect to the base 31. good.

The console device 40 has a memory 41 , a display 42 , an input interface 43 and a processing circuit 44 . Although the console device 40 is described as being separate from the imaging device 10 , the imaging device 10 may include the console device 40 or a part of each component of the console device 40 . The console device 40 corresponds to, for example, a medical image processing device.

In the following explanation, the console device 40 is assumed to execute a plurality of functions with a single console, but the plurality of functions may be executed by separate consoles. For example, the functions of the processing circuit 44 such as the image generation function 445, which will be described later, may be distributed and installed in different console devices.

The memory 41 is a storage device such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), or an integrated circuit that stores various information. Moreover, the memory 41 may be a portable storage medium such as a CD (Compact Disc), a DVD (Digital Versatile Disc), a flash memory, or the like, in addition to an HDD, SSD, or the like. The memory 41 may be a driving device that reads and writes various information with semiconductor memory devices such as flash memory and RAM (Random Access Memory). Moreover, the storage area of the memory 41 may be in the X-ray diagnostic apparatus 1 or in an external storage device connected via a network.

The memory 41 stores, for example, X-ray images, programs executed by the processing circuit 44, various data used for processing by the processing circuit 44, and the like. The memory 41 is an example of a storage unit.

The display 42 displays various information. For example, the display 42 outputs a medical image (X-ray image) generated by the processing circuit 44, a GUI (Graphical User Interface) for receiving various operations from the operator, and the like. For example, the display 42 is a liquid crystal display or a CRT (Cathode Ray Tube) display. Also, the display 42 is an example of a display unit. Also, the display 42 may be provided in the imaging device 10 . The display 42 may be of a desktop type, or may be configured by a tablet terminal or the like capable of wireless communication with the main body of the console device 40 .

The input interface 43 receives various input operations from the operator, converts the received input operations into electrical signals, and outputs the electrical signals to the processing circuit 44 . For example, the input interface 43 receives subject information, imaging conditions, input of various command signals, and the like from the operator. For example, the input interface 43 includes a trackball, a mouse, a keyboard, a trackball, a switch, a button, a joystick, and an operation surface for instructing movement of the C-arm 14, setting a region of interest (ROI), and performing fluoroscopy. It is realized by a touch pad that performs an input operation by touching, a touch panel display in which a display screen and a touch pad are integrated, a foot switch, and the like. Also, the input interface 43 is an example of an input unit and an operation unit. Also, the input interface 43 may be provided in the imaging device 10 . Also, the input interface 43 may be composed of a tablet terminal or the like capable of wireless communication with the main body of the console device 40 . It should be noted that the input interface 43 is not limited to having physical operation components such as a mouse and keyboard. For example, the input interface 43 includes an electrical signal processing circuit that receives an electrical signal corresponding to an input operation from an external input device provided separately from the device and outputs the electrical signal to the processing circuit 44. . The input interface 43 is an example of an operation unit for instructing imaging of moving images using the X-ray tube and the X-ray detector 13 .

The processing circuit 44 controls the operation of the X-ray diagnostic apparatus 1 as a whole. The processing circuit 44 executes a system control function 441, an imaging condition setting function 442, a drive control function 443, an X-ray control function 444, an image generation function 445, and a display control function 446 by calling and executing programs in the memory 41. It is a processor that

In FIG. 1, the single processing circuit 44 realizes the system control function 441, the imaging condition setting function 442, the drive control function 443, the X-ray control function 444, the image generation function 445, and the display control function 446. However, a processing circuit may be configured by combining a plurality of independent processors, and each function may be realized by executing a program by each processor. A system control function 441, an imaging condition setting function 442, a drive control function 443, an X-ray control function 444, an image generation function 445, and a display control function 446 are respectively a system control circuit, an imaging condition setting circuit, a drive control circuit, and an X-ray control circuit. They may also be referred to as line control circuitry, image processing circuitry and display control circuitry, and may be implemented as separate hardware circuits.

The term "processor" used in the above description includes, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or an ASIC, a programmable logic device (e.g., Simple Programmable Logic Device (SPLD) , Complex Programmable Logic Device (CPLD), Field Programmable Gate Array (FPGA), etc. Processors function by reading and executing programs stored in memory circuits. Instead of storing the program in the memory circuit, the program may be directly embedded in the circuit of the processor.In this case, the processor can read and execute the program embedded in the circuit. Note that each processor of this embodiment is not limited to being configured as a single circuit for each processor, but is configured as a single processor by combining a plurality of independent circuits, and its function is implemented by 1 may be integrated into a single processor to implement its functions.

The processing circuit 44 controls each of the plurality of components in the X-ray diagnostic apparatus 1 by the system control function 441 based on the input operation received from the operator via the input interface 43 . For example, the processing circuit 44 controls various components in the imaging device 10 according to imaging conditions. The processing circuit 44 that implements the system control function 441 is an example of a system control section.

The processing circuit 44 sets imaging conditions (hereinafter referred to as imaging conditions) by an imaging condition setting function 442 . Fluoroscopy is an example of video imaging. The processing circuit 44 that implements the imaging condition setting function 442 is an example of an imaging condition setting unit.

The imaging conditions include conditions for X-ray irradiation by an X-ray tube (hereinafter referred to as X-ray conditions), magnification of AGC (Auto Gain Control) (hereinafter referred to as AGC magnification), information on additional filters to be used (hereinafter referred to as , filter specific information), detector spatial resolution, field size, source image distance (hereinafter referred to as SID), and the number of pixels that make up one pixel of an X-ray image. at least one of the size of the area in the FPD used for the above (hereinafter referred to as FPD pixel size). The filter specific information includes at least one of the type of additional filter used, the thickness of the additional filter used, and the like. The imaging conditions may be referred to as fluoroscopy conditions. The imaging condition setting function 442 is an example of an X-ray condition determination unit that determines X-ray conditions.

The X-ray conditions include, for example, at least one of tube current, tube voltage, focal spot size, pulse width, pulse rate (number of pulses per unit time), and the like.

In addition, the processing circuit 44 uses the imaging condition setting function 442 to determine the output of the X-ray detector 13 in the fluoroscopy performed immediately before in an examination including the execution of fluoroscopy a plurality of times. Determine the size of the X-ray focal spot. The processing circuitry 44 also sets the focal size of the X-ray according to the determined result. Here, the "focus size" and the "focus size" may correspond one-to-one or many-to-one. In the case of one-to-one correspondence, both "focus size" and "focus size" may be determined and set as "small focus" or "medium focus". Alternatively, even in the case of one-to-one correspondence, when using control grid electrodes, both "focus size" and "focus size" are determined and set as values within the range of, for example, 0.2 to 0.7 mm. You may On the other hand, in the case of multi-to-one correspondence, the "focus size" is determined, for example, as a value within the range of 0.2 to 0.4 mm, and the "focus size" is set as a small focus. may Alternatively, the "focus size" may be determined as a value within the range of 0.5 to 0.7 mm, for example, and the "focus size" may be set as a medium focus.

Specifically, the processing circuit 44 uses the imaging condition setting function 442 to perform the first fluoroscopy based on the output of the X-ray detector 13 in the first fluoroscopy executed in response to the operation to the input interface 43. determining the focal spot size in the second fluoroscopy to be performed later in response to an operation to the input interface 43; determines the focus size in the third fluoroscopy performed in response to the operation of . Supplementally, the processing circuit 44, for example, in the first moving image capturing and the second moving image capturing, based on the output of the X-ray detector 13 in the previous frame, the X-ray irradiation conditions and X Control is performed to set at least one of the gains applied to the line image. In addition, the processing circuit 44 determines the focal point of the X-rays in the second moving image capturing based on the output of the X-ray detector 13 in the first moving image capturing through the X-ray irradiation conditions in the first moving image capturing. determine the size of Furthermore, the processing circuit 44 determines the focal point of the X-rays in the third moving image capturing based on the output of the X-ray detector 13 in the second moving image capturing through the X-ray irradiation conditions in the second moving image capturing. determine the size of

Further, the processing circuit 44 acquires the X-ray conditions in the first fluoroscopy, for example, based on the X-ray image generated by the output of the X-ray detector 13 in the first fluoroscopy, The line condition may be used to determine the focal spot size in the second perspective. The first fluoroscopy is an example of the first moving image capturing, the second fluoroscopy is an example of the second moving image capturing, and the third fluoroscopy is an example of the third moving image capturing.

The processing circuit 44 uses the drive control function 443 to control the C-arm drive device 142 and the bed drive device 32 based on information on driving the C-arm 14 and the tabletop 33 input from the input interface 43, for example. The processing circuit 44 that implements the drive control function 443 is an example of a drive control section.

The processing circuit 44 uses the X-ray control function 444 to read, for example, information from the system control function 441, and sets X-ray conditions such as tube current, tube voltage, focal size, irradiation time, and pulse width in the high voltage generator 11. control. Note that the X-ray control function 444 is a function of selecting a filament to be used from a plurality of filaments provided in the bulb of the X-ray tube based on the size of the X-ray focal point determined by the imaging condition setting function 442. may include The processing circuit 44 that implements the X-ray control function 444 is an example of an X-ray controller.

The processing circuit 44 uses the image generation function 445 to generate an X-ray image based on the data output from the X-ray detector 13, for example. At this time, the processing circuit 44 performs AGC. AGC is control for adjusting the brightness of the generated X-ray image in order to keep the brightness of the generated X-ray image constant. Supplementally, AGC could not ensure the detector incident dose due to the upper limit of the X-ray incident dose to the subject per unit time (hereinafter referred to as the dose limit) and the tube output limit. is a digital gain multiplied by the entire image to ensure the brightness of the X-ray image. The AGC magnification is the ratio of the brightness of the X-ray image after adjustment to the X-ray image before adjustment by AGC. Note that the processing circuit 44 may perform various types of synthesizing processing, subtraction processing, and the like on the generated X-ray image. An X-ray image is an example of medical data. The processing circuit 44 that implements the image generation function 445 is an example of an image generator.

The processing circuit 44 uses the display control function 446 to read, for example, a signal from the system control function 441 , obtain a desired X-ray image from the memory 41 , and display it on the display 42 . The processing circuit 44 that implements the display control function 446 is an example of a display control unit.

Next, the operation of fluoroscopy execution processing executed by the X-ray diagnostic apparatus 1 will be described. The fluoroscopy execution process is a process of executing fluoroscopy of the subject according to the operation on the input interface 43 in the examination.

Note that the processing procedure in the fluoroscopy execution processing described below is merely an example, and each processing can be changed as appropriate as possible. Further, in the processing procedures described below, steps can be omitted, replaced, and added as appropriate according to the embodiment.

FIG. 2 is a flow chart showing an example of the procedure of fluoroscopy execution processing according to the present embodiment. The processing circuit 44 starts fluoroscopy execution processing, for example, when an instruction to start examination is input through the input interface 43 .

(perspective processing)
(Step S101)
The processing circuitry 44 executes an imaging condition setting function 442 . The processing circuit 44 uses the imaging condition setting function 442 to perform processing for setting imaging conditions for fluoroscopy to be executed next (hereinafter referred to as imaging condition setting processing). Details of the imaging condition setting process will be described later.

(Step S102)
The processing circuitry 44 determines whether or not an instruction to end the examination of the subject has been input. At this time, the processing circuit 44 determines whether or not an instruction to end the examination has been input, for example, by detecting an input of an instruction to end the examination of the subject through the input interface 43 . If an instruction to end the examination is input (step S102-Yes), the processing circuit 44 ends the fluoroscopy execution process.

If an instruction to end the inspection is not input (step S102-No), the process proceeds to step S103.

(Step S103)
The processing circuit 44 determines whether or not an instruction to execute fluoroscopy has been input according to the operation of the input interface 43 by the operator. At this time, the processing circuit 44 determines whether or not an instruction to execute fluoroscopy has been input, for example, by detecting whether or not a foot switch is being operated. If an instruction to execute (start) fluoroscopy is input (step S103-Yes), the process proceeds to step S104. If an instruction to execute (start) fluoroscopy is not input (step S103-No), the process returns to step S102, and the processing circuit 44 either receives an instruction to end the examination or executes (starts) fluoroscopy. waits until you enter an instruction to

(Step S104)
The processing circuit 44 executes a system control function 441 , a drive control function 443 , an X-ray control function 444 and an image generation function 445 to perform fluoroscopy using the imaging device 10 .

During execution of one fluoroscopy, the processing circuit 44 uses the image generation function 445 to generate a plurality of X-ray images, which are frames in time series, and uses the image generation function 445 to generate the generated X-ray images. Store in memory 41 . Then, the processing circuit 44 causes the display 42 to display an X-ray moving image generated from the plurality of generated X-ray images by the display control function 446 . At this time, the processing circuit 44 performs AGC using the image generation function 445 .

In addition, the processing circuit 44 controls the X-ray conditions in the subsequent frame based on the output of the X-ray detector 13 in the previous frame during execution of fluoroscopy by the system control function 441 and the X-ray control function 444. I do. In other words, the processing circuit 44 performs feedback control to change the X-ray conditions and the like based on changes in subject conditions during one fluoroscopy. For example, in feedback control, the processing circuit 44 detects changes in the thickness of the subject or the structure of the internal tissue of the subject due to the operation of moving the tabletop 33 on which the subject is placed during the execution of one fluoroscopy. In this case, the brightness, contrast, etc. of the X-ray image generated in the previous frame are detected, and the tube voltage is adjusted so that the brightness, contrast, etc. of the X-ray image displayed in the subsequent frame satisfies predetermined conditions. , controls the tube current, pulse width, and AGC multiplier. Through feedback control, an appropriate tube voltage, tube current, pulse width, and AGC magnification are selected even if subject conditions change during one fluoroscopy. Therefore, at the end of fluoroscopy, at least one of tube voltage, tube current, pulse width, and AGC magnification is appropriately controlled according to changes in subject conditions. In addition, the X-ray image finally generated in one fluoroscopy is adjusted so that the brightness, contrast and the like satisfy predetermined conditions.

(Step S105)
The processing circuit 44 determines whether or not an instruction to end fluoroscopy has been input. At this time, the processing circuit 44 determines whether or not an instruction to end fluoroscopy has been input, for example, by detecting whether or not a foot switch is being operated by the operator. If an instruction to end fluoroscopy has been input (step S105-Yes), the process proceeds to step S106. The processing circuit 44 continues execution of fluoroscopy by the process of step S104 until an instruction to end fluoroscopy is input.

(Step S106)
The processing circuit 44 executes a system control function 441 , a drive control function 443 , an X-ray control function 444 , and an image generation function 445 to end fluoroscopy by radiography. When fluoroscopy by X-ray imaging is completed, the process returns to step S101.

The processing circuit 44 sets the imaging conditions for the next fluoroscopy by executing the imaging condition setting process based on the end of the fluoroscopy by X-ray imaging. Specifically, the processing circuit 44 determines the focal size of the X-rays in the second moving image pickup based on the end of the first moving image pickup, and determines the size of the X-ray focus when the second moving image pickup ends. Based on this, the size of the X-ray focal point in the third moving image capturing is determined. After setting imaging conditions for fluoroscopy to be executed next by the process of S101, the processing circuit 44 determines whether or not an instruction to end the examination is input by the process of step S102. Therefore, even if the next fluoroscopy is not performed, imaging conditions for the next fluoroscopy are set by completing the examination.

As described above, in the fluoroscopy execution process, the processing circuit 44 starts fluoroscopy when an instruction to execute fluoroscopy is input through the input interface 43 . When the instruction to execute fluoroscopy is canceled in the input interface 43, the processing circuit 44 ends the fluoroscopy. Then, when an instruction to execute fluoroscopy is input again through the input interface 43, the processing circuit 44 executes the next fluoroscopy. During execution of one fluoroscopy, the processing circuit 44 controls the imaging conditions based on changes in subject conditions so that the image quality of the X-ray image is appropriately ensured.

(imaging condition setting process)
Next, the operation of imaging condition setting processing executed by the X-ray diagnostic apparatus 1 will be described. Note that the processing procedure in the imaging condition setting processing described below is merely an example, and each processing can be changed as appropriate as possible. Further, in the processing procedures described below, steps can be omitted, replaced, and added as appropriate according to the embodiment. FIG. 3 is a flow chart showing an example of the procedure of imaging condition setting processing according to the present embodiment.

(Step S111)
The processing circuit 44 obtains a number (hereinafter referred to as the number of times of fluoroscopy) indicating the number of times of fluoroscopy after the start of examination for the next fluoroscopy. The processing circuitry 44 determines the number of fluoroscopic observations for the next fluoroscopic examination, for example, by obtaining the number of fluoroscopic observations performed so far in the examination. For example, if no fluoroscopy has been performed so far after the start of the examination, the processing circuitry 44 determines that the next fluoroscopy is the first fluoroscopy after the start of the examination, and sets the number of fluoroscopy to one. Further, if one fluoroscopy has been performed so far after the start of the examination, the processing circuit 44 determines that the next fluoroscopy is the second fluoroscopy after the start of the examination, and sets the number of times of fluoroscopy to 2. . As an example, processing when the number of times of fluoroscopy is N will be described below.

(Step S112)
The processing circuit 44 determines whether or not the number of fluoroscopy times N for the next fluoroscopy is one. The processing circuit 44 determines whether or not the number of times N of fluoroscopy for the next fluoroscopy is 1, thereby determining whether the fluoroscopy to be performed next is the first fluoroscopy after the start of the examination, or It is determined whether it is the second or later fluoroscopy. If the number of times of fluoroscopy N is 1 (step S112-Yes), it is determined that the next fluoroscopy is the first fluoroscopy after the start of examination, and the process proceeds to step S113. If the number of times of fluoroscopy N is not 1 (step S112-Yes), that is, if the number of times of fluoroscopy N is 2 or more, it is determined that the next fluoroscopy to be performed is the second or subsequent fluoroscopy after the start of the examination, and the process is terminated. The process proceeds to step S114.

(Step S113)
The processing circuit 44 reads the default imaging conditions for the first fluoroscopy after the start of the examination from the memory 41, and sets the read default imaging conditions as the imaging conditions for the next fluoroscopy. At this time, the processing circuit 44 sets the small focal point as the focal point size in the next fluoroscopy.

(Step S114)
When the number of times of fluoroscopy N is 2 or more, the processing circuit 44 acquires the imaging conditions for the number of times of fluoroscopy (N−1). The processing circuit 44 acquires the imaging conditions for the N−1 fluoroscopy by reading the imaging conditions for the N−1 fluoroscopy stored in the memory 41, for example. The processing circuit 44 acquires the imaging conditions for the fluoroscopy performed for the number of fluoroscopy times of N−1, thereby acquiring the imaging conditions for the fluoroscopy performed immediately before among the fluoroscopy performed after the start of the examination. The processing circuit 44 acquires, for example, the focus size, filter specification information, tube voltage, tube current, pulse width, and AGC magnification as imaging conditions for fluoroscopy for the number of times of fluoroscopy (N−1). As described above, during execution of fluoroscopy, feedback control is performed to change X-ray conditions and the like based on changes in subject conditions, and at the end of fluoroscopy, tube voltage, tube current, pulse width, and AGC magnification At least one of them is appropriately controlled according to changes in subject conditions. Therefore, by acquiring the imaging conditions for the fluoroscopy performed immediately before, it is possible to acquire the imaging conditions that are appropriately controlled according to changes in the subject conditions. In addition, by arithmetic processing based on the X-ray image generated in the immediately preceding fluoroscopy, imaging conditions that are more appropriately controlled according to changes in subject conditions are calculated, and the calculated imaging conditions are used in the immediately preceding execution. may be acquired as imaging conditions in fluoroscopy.

(Step S115)
The processing circuit 44 determines the incident dose to the X-ray detector in the X-ray generator 12 for each of the cases of performing fluoroscopy with a small focus size and with a medium focus size in fluoroscopy with the number of times of fluoroscopy N. is as close as possible to the X-ray dose required to ensure the quality of the X-ray image (hereinafter referred to as target dose). The imaging condition estimated value is an imaging condition when the conditions related to the short-time rating and continuous rating of the tube are satisfied and the incident dose to the X-ray detector is brought as close as possible to the target dose. Specifically, for example, when the number of times of fluoroscopy is N=2, the processing circuit 44 obtains the X-ray focal size, tube voltage, tube current and Based on the pulse width, the AGC magnification, and the filter specific information, the imaging condition estimated value in the second moving image imaging may be calculated. Here, when the number of times of fluoroscopy is N=2, the first moving image pickup and the second moving image pickup correspond to the (N-1)th moving image pickup and the Nth moving image pickup, respectively. Further, when the number of times of fluoroscopy is N=3, the processing circuit 44 obtains the X-ray focal size, tube voltage, tube current and pulse width, AGC An imaging condition estimated value in the third moving image imaging may be calculated based on the magnification and the filter specifying information. Similarly, when the number of times of fluoroscopy is N=3, the second moving image capturing and the third moving image capturing correspond to the (N-1)th moving image capturing and the Nth moving image capturing, respectively.

The imaging condition estimated value is the X-ray condition (hereinafter referred to as the X-ray condition estimated value) when the incident dose of the X-ray detector is brought as close as possible to the target dose in the X-ray generating unit 12, and the X-ray generating unit 12 and an AGC scale factor (hereinafter AGC scale estimate) expected to be applied by AGC when the X-ray detector entrance dose is brought as close as possible to the target dose. The X-ray condition estimated value is the tube voltage (hereinafter referred to as the tube voltage estimated value) when the incident dose of the X-ray detector is brought as close as possible to the target dose in the X-ray generator 12, and the X A tube current (hereinafter referred to as a tube current estimated value) when the line detector incident dose is brought as close as possible to the target dose, and a case where the X-ray detector incident dose is brought as close as possible to the target dose in the X-ray generator 12 pulse width (hereinafter referred to as pulse width estimate). Note that the imaging condition estimated values are the tube voltage estimated value that satisfies the conditions related to the output of the X-ray tube (hereinafter referred to as the target output) necessary to ensure the image quality of the X-ray image, and the tube current estimated value that satisfies the conditions. , a pulse width estimate that satisfies the condition for the target output, and an AGC magnification estimate that satisfies the condition for the target output.

As a process for calculating the imaging condition estimated value, for example, X-ray conditions for the current fluoroscopy are set to X{kV, mA, msec, AGC}, and the function of the previous or current conditions is set to h(Focus, BF, _{just before} BF, _{immediately before} kV, _{immediately before} mA, _{immediately before} msec, and _{immediately before} AGC), a process based on the following equation is executed.
X {kV, mA, msec, AGC} = h (Focus, BF, _{just before} BF, _{just before} kV, _{just before} mA, _{just before} msec, _{just before} AGC)
However, in the above formula, kV: tube voltage, mA: tube current, msec: pulse width, AGC: AGC magnification, Focus: focal size, BF: filter specific information, subscript "immediately before": conditions in previous fluoroscopy, subscript No characters: Conditions for fluoroscopy this time.

In the process of calculating the imaging condition estimated value, the processing circuit 44 first calculates the target output based on the focus size, the filter specification information, the tube voltage, the tube current, the pulse width, and the AGC magnification in the fluoroscopy at the number of fluoroscopy times of N−1. Calculate Next, the processing circuit 44 calculates the estimated tube voltage value Vp1, the estimated tube current value Ip1, the pulse width, and An estimated value Wp1, an estimated AGC magnification value Mp1, and an estimated tube voltage value Vp2, an estimated tube current value Ip2, an estimated pulse width value Wp2, and an estimated AGC magnification value Mp2 when fluoroscopy is performed with a medium focus size. are calculated respectively. If the focal size of each of the small focal point and the medium focal point is the same as the previous focal size, an imaging condition estimated value representing substantially the same imaging condition as the previous imaging condition is calculated. Supplementally, for example, when the number of times of fluoroscopy is N=2, the processing circuit 44 calculates the imaging condition estimated value in the second moving image imaging for each of a plurality of different focus sizes of X-rays, An imaging condition estimated value corresponding to the focal size determined as the focal size of the line is determined as the imaging condition for the second moving image imaging. Similarly, for example, when the number of times of fluoroscopy is N=3, the processing circuit 44 calculates an imaging condition estimated value in the third moving image imaging for each of a plurality of focus sizes with different X-ray focus sizes, An imaging condition estimated value corresponding to the focal size determined as the X-ray focal size is determined as the imaging condition for the third moving image imaging.

(Step S116)
The processing circuit 44 determines whether or not the focus size of the fluoroscopy for the number of times of fluoroscopy (N−1) is a small focus based on the imaging conditions for the fluoroscopy for the number of times of fluoroscopy (N−1) acquired in step S114. If the focus size of fluoroscopy at the number of times of fluoroscopy N−1 is a small focus (step S116-Yes), the process proceeds to step S117. If the fluoroscopy focal size of N−1 is not a small focus (step S116-No), the processing circuit 44 determines that the fluoroscopy focal size of N−1 is a medium focal point, and the process proceeds to step S121. proceed to

(Step S117)
The processing circuit 44 determines whether or not the estimated tube voltage value Vp1 is equal to or less than the threshold value Vth1. The threshold Vth1 is a value for determining whether the contrast of the generated X-ray image satisfies a predetermined condition. The threshold Vth1 is, for example, a value determined from the range of 20 to 150 kV. A predetermined value may be set as the threshold Vth1, or may be input by the operator for each examination. The threshold Vth1 is an example of a determination value. Also, the threshold Vth1 is an example of a first value. If the tube voltage estimated value Vp1 is less than or equal to the threshold value Vth1 (step S117-Yes), the process proceeds to step S118. If the estimated tube voltage Vp1 is not less than or equal to the threshold Vth1 (step S117-No), that is, if the estimated tube voltage Vp1 is greater than the threshold Vth1, the process proceeds to step S119.

(Step S118)
The processing circuit 44 determines whether or not the exposure limit attainment index R is equal to or less than the threshold value β. Here, the dose limit attainment index R (=G/L×100[%]) is the ratio of the dose estimate value G to the dose limit L. The dose limit (Dose Limit) L is an upper limit value for the dose of X-rays (incident dose rate) incident on the subject per unit time. That is, the exposure limit L is the upper limit of the exposure dose. The exposure limit L is set in advance according to, for example, the country of use. Exposure limit L is, for example, a value such as 50 mGr/min or 87 mGr/min. The estimated radiation dose G is the amount of X-rays that are expected to enter the subject when fluoroscopy is performed the number of times of fluoroscopy N under the imaging condition estimated value when fluoroscopy is performed with a medium focus size. dose. The threshold value β is a value for determining whether or not there is a sufficient margin in the estimated radiation dose G with respect to the exposure limit L. The threshold β is an example of a dose determination value. The threshold β is, for example, a value determined from a range of 90-99%. A predetermined value may be set as the threshold β, or may be input by the operator for each fluoroscopy.

In the process of step S118, the processing circuit 44 first performs the following based on the tube voltage estimated value Vp2, the tube current estimated value Ip2, the pulse width estimated value Wp2, the AGC magnification estimated value Mp2, and the filter specific information in the N-th fluoroscopy. , the dose estimate G is calculated. Then, based on the estimated radiation dose G and the exposure limit L, the exposure limit attainment index R is calculated. If the exposure limit attainment index R is equal to or less than the threshold β (step S118-Yes), the processing circuit 44 sets the exposure limit L when fluoroscopy is performed the number of times N of fluoroscopy with the imaging condition estimated value corresponding to the middle focus as the imaging condition. It is determined that there is a sufficient margin of the incident dose rate for , and the process proceeds to step S120. When the exposure limit attainment index R is greater than the threshold β (step S118-No), the processing circuit 44 performs fluoroscopy the number of times N of fluoroscopy with the imaging condition estimated value corresponding to the middle focus as the imaging condition. It is determined that the margin of the incident dose rate is insufficient, and the process proceeds to step S119.

(Step S119)
The processing circuit 44 sets the focus size in fluoroscopy for the number of times of fluoroscopy N to a small focus. Further, the processing circuit 44 sets the imaging condition estimated value corresponding to the small focus as the imaging condition for the N fluoroscopy times. At this time, the processing circuit 44 sets the tube voltage estimated value Vp1 as the tube voltage in the fluoroscopy of the number N of fluoroscopy, the tube current estimated value Ip1 as the tube current in the fluoroscopy of the number N of the fluoroscopy, and the pulse width estimated value Wp1 as the number of fluoroscopy. It is set as the pulse width in N fluoroscopy, and the AGC magnification estimated value Mp1 is set as the AGC magnification in N fluoroscopy times. Then, the processing circuit 44 ends the imaging condition setting process, and the process proceeds to step S103.

(Step S120)
The processing circuit 44 sets the focus size in the fluoroscopy of the number N of fluoroscopy to the middle focus. In addition, the processing circuit 44 sets the imaging condition estimated value corresponding to the middle focus as the imaging condition for the N fluoroscopy times. At this time, the processing circuit 44 sets the tube voltage estimated value Vp2 as the tube voltage in the fluoroscopy of the number of times N of fluoroscopy, the tube current estimated value Ip2 as the tube current in the fluoroscopy of the number of times of the fluoroscopy of N, and the pulse width estimated value Wp2 as the number of times of the fluoroscopy. It is set as the pulse width in N fluoroscopy, and the AGC magnification estimated value Mp2 is set as the AGC magnification in N fluoroscopy times. Then, the processing circuit 44 ends the imaging condition setting process, and the process proceeds to step S103.

(Step S121)
The processing circuit 44 determines whether or not the estimated tube voltage value Vp1 is equal to or less than the threshold value Vth2. The threshold Vth2 is smaller than the threshold Vth1 by the set value α1. That is, Vth2=Vth1-α. The set value α1 is a value representing the margin of the tube voltage for determining switching from the medium focus to the small focus, and is a value determined within the range of 1 to 10 kV, for example. The set value α1 may be set to a predetermined value, or may be input by the operator for each examination. The threshold Vth2 is an example of a determination value. Also, the threshold Vth2 is an example of a second value. If the tube voltage estimated value Vp1 is less than or equal to the threshold value Vth2 (step S121-Yes), the process proceeds to step S122. If the tube voltage estimated value Vp1 is not less than or equal to the threshold value Vth2 (step S121-No), that is, if the tube voltage estimated value Vp1 is greater than the threshold value Vth2, the process proceeds to step S123.

(Step S122)
The processing of step S122 is the same as the processing of step S119. That is, the processing circuit 44 sets the focal point size in fluoroscopy of the number N of fluoroscopy times to a small focal point. Then, the processing circuit 44 ends the imaging condition setting process, and the process proceeds to step S103.

(Step S123)
The processing of step S123 is the same as the processing of step S120. That is, the processing circuit 44 sets the focus size in the fluoroscopy of the number N of times of fluoroscopy to the middle focal point. Then, the processing circuit 44 ends the imaging condition setting process, and the process proceeds to step S103.

When the imaging condition setting process ends, the processing circuit 44 executes fluoroscopy N times based on the imaging conditions set in the imaging condition setting process. Then, when the next fluoroscopy is performed after the fluoroscopy is completed for the number of times of fluoroscopy N, the processing circuit 44 again executes the imaging condition setting process in step S101. At this time, the processing circuit 44, in the same manner as the processing for setting the imaging conditions for the N fluoroscopy, based on the X-ray conditions for the N fluoroscopy, performs imaging, including the focus size for the N+1 fluoroscopy, for the N+1 fluoroscopy. Determine conditions.

The effects of the X-ray diagnostic apparatus 1 according to this embodiment will be described below.

The X-ray diagnostic apparatus 1 according to the present embodiment controls the operation unit after the first moving image is captured based on the output of the X-ray detector 13 in the first moving image capturing performed in response to the operation of the operation unit. A focus size of X-rays is determined in the second moving image imaging performed according to the operation. Further, based on the output of the X-ray detector 13 in the second moving image capturing, the size of the X-ray focal point in the third moving image capturing performed in accordance with the operation to the operation unit after the second moving image capturing to decide.

In summary, the X-ray diagnostic apparatus 1 of the present embodiment operates on the input interface 43 based on the output of the X-ray detector 13 in the fluoroscopy performed immediately before according to the operation on the input interface 43. Determine the focal spot size in the next performed fluoroscopy.

For example, the X-ray diagnostic apparatus 1 of the present embodiment inputs after the number of times of fluoroscopy (N−1) based on the X-ray conditions for the number of times of fluoroscopy (N−1) executed according to the operation of the input interface 43. A focal size is determined in N fluoroscopy to be executed according to an operation to the interface 43, and based on the X-ray conditions in the N fluoroscopy, after the N fluoroscopy, an operation to the input interface 43 is performed. The focal size in N+1 fluoroscopy to be performed accordingly is determined.

Further, the X-ray diagnostic apparatus 1 of the present embodiment determines the focal size of the X-ray at the start of the second moving image capturing based on the output of the X-ray detector 13 at the end of the first moving image capturing. Then, based on the output of the X-ray detector 13 at the end of the second moving image capturing, the X-ray focal size at the start of the third moving image capturing is determined.

For example, the X-ray diagnostic apparatus 1 of the present embodiment determines the size of the X-ray focal point at the start of the number of times N of fluoroscopy based on the X-ray conditions at the end of the number of times of fluoroscopy N−1, Based on the output of the X-ray conditions at the end of N fluoroscopy, the size of the X-ray focal point at the start of N+1 fluoroscopy is determined.

Further, the X-ray diagnostic apparatus 1 of the present embodiment, based on the output of the X-ray detector 13 in the first moving image capturing, uses a specific X-ray focal size for the second moving image capturing. calculating an estimated imaging condition that satisfies a condition related to the target output in , and determining the size of the X-ray focal point in the second moving image capturing based on the estimated imaging condition in the second moving image capturing. Further, based on the output of the X-ray detector 13 in the second moving image capturing, the imaging condition estimated value is calculated for the third moving image capturing, and based on the imaging condition estimated value in the third moving image capturing, the third moving image is obtained. Determine the size of the X-ray focal point in the imaging.

For example, the X-ray diagnostic apparatus 1 of the present embodiment calculates the tube voltage estimated value Vp1 in fluoroscopy for the number of times of fluoroscopy (N−1) based on the X-ray conditions for fluoroscopy for the number of times of fluoroscopy (N−1), and based on the tube voltage estimated value Vp1 Determine the focal spot size for N fluoroscopy, calculate the estimated tube voltage Vp1 for N+1 fluoroscopy based on the X-ray conditions for N fluoroscopy, and calculate N+1 fluoroscopy based on the estimated tube voltage Vp1 determines the focal spot size in perspective.

That is, with the above configuration and operation, according to the X-ray diagnostic apparatus 1 of the present embodiment, based on the output of the X-ray detector 13 in the previous fluoroscopy, the next fluoroscopy executed by depressing the foot switch again. can be determined. Therefore, in the next fluoroscopy, the focus size can be set according to the X-ray conditions in the previous fluoroscopy. Therefore, even if the thickness of the subject changes during the previous fluoroscopy, the focal spot size appropriate for producing an X-ray image with a predetermined contrast may change due to feedback control. Based on the X-ray conditions controlled to appropriate values according to the thickness of the subject, the appropriate focal spot size in the next fluoroscopy can be automatically set. As a result, it is possible to improve the image quality of the X-ray image generated in the next fluoroscopy. For example, when the subject is thin and the tube output has a margin, a sharp image can be generated by setting a small focus. On the other hand, when the subject is thick and the tube voltage is high with a small focus, an image with high contrast and little noise can be generated by switching to a medium focus with high output.

Further, when the imaging condition estimated value in the second moving image capturing is equal to or less than the determination value, the X-ray diagnostic apparatus 1 of the present embodiment sets the focus size of the X-ray in the second moving image capturing to the first focus size is set, and when the imaging condition estimated value in the second moving image capturing is larger than the judgment value, the second focal size larger than the first focal size is set as the size of the X-ray focal point in the second moving image capturing. decide. Further, when the imaging condition estimated value in the third moving image capturing is equal to or less than the determination value, the first focus size is set as the size of the X-ray focus in the third moving image capturing, and the imaging in the third moving image capturing If the condition estimation value is larger than the determination value, a second focus size is determined as the size of the X-ray focus in the third moving image capturing.

In summary, for example, in the process of step S121, the X-ray diagnostic apparatus 1 of the present embodiment changes the focal size in N fluoroscopy when the estimated tube voltage Vp1 in N fluoroscopy is equal to or less than the threshold value Vth2. If the small focus is determined and the tube voltage estimated value Vp1 in the N fluoroscopy is larger than the threshold value Vth2, the medium focus is determined as the focal size in the N fluoroscopy.

For example, if the thickness of the subject decreased during the previous fluoroscopy run using a medium focal spot size, less X-ray tube power would be required to produce an X-ray image of a given brightness or higher. Become. In such a case, according to the X-ray diagnostic apparatus 1 of the present embodiment, the tube voltage estimated value Vp1 at the small focus becomes equal to or smaller than the threshold Vth2, and the focal size in the next fluoroscopy is set to the small focus. As a result, when there is a margin in the output of the X-ray tube, that is, when an X-ray image with a predetermined contrast or more can be generated even when a small focus with a small output is used, in the next fluoroscopy By setting the focus size to a small focus, an X-ray image with higher resolution can be generated than when the focus size is set to a medium focus.

Also, for example, when the thickness of the subject increases during the previous fluoroscopy using a small focus size, the number of X-ray tubes required to generate an X-ray image with a predetermined brightness or more The power is increased and the contrast of the generated x-ray image is reduced. In such a case, according to the X-ray diagnostic apparatus 1 of the present embodiment, the tube voltage estimated value Vp1 at the small focus becomes larger than the threshold Vth2, and the focus size in the next fluoroscopy is set to the medium focus. Therefore, in the next fluoroscopy, the focus size is switched to the middle focus that can increase the output of the X-ray tube compared to the small focus, thereby securing the necessary dose and suppressing the tube voltage. can be done. Therefore, it is possible to secure the contrast of the X-ray image and generate an X-ray image with less noise than when the small focus size is continuously used.

Further, when the X-ray focus size in the first moving image capturing is the first focus size, the X-ray diagnostic apparatus 1 of the present embodiment performs the second moving image capturing using the first value as the determination value. If the size of the X-ray focus in the first moving image capturing is the second focus size, a second value different from the first value is used as the determination value , determines the size of the X-ray focus in the second movie acquisition. Further, when the size of the X-ray focal point in the second moving image capturing is the first focal size, the first value is used as a determination value to determine the size of the X-ray focal point in the third moving image capturing. , if the size of the X-ray focal point in the second moving image capturing is the second focal size, the second value is used as the determination value to determine the size of the X-ray focal point in the third moving image capturing. For example, the second value is smaller than the first value.

In summary, the X-ray diagnostic apparatus 1 of the present embodiment, for example, when the focus size in fluoroscopy of the number of times of fluoroscopy of N−1 is a small focus, based on the tube voltage estimated value Vp1 and the threshold value Vth1 of fluoroscopy of the number of times of fluoroscopy of N , the focus size in fluoroscopy for the number of times of fluoroscopy is determined, and if the focus size in fluoroscopy for the number of times of fluoroscopy of N−1 is medium focus, the number of fluoroscopy times Determine the focal spot size in N perspectives. Here, the threshold Vth2 is smaller than the threshold Vth1.

That is, with the above configuration and operation, according to the X-ray diagnostic apparatus 1 of the present embodiment, the threshold for determining whether or not to switch the focus size in the next fluoroscopy from the middle focus to the small focus, is different from the threshold for switching the focus size to . Therefore, for example, even if the tube voltage estimated value Vp1 switches between a range smaller than the threshold Vth and a range larger than the threshold Vth each time the previous fluoroscopy is switched to the next fluoroscopy, Since the threshold for determining the switching of the focus size to the small focus and the threshold for determining the switching of the focus size from the small focus to the medium focus are different, it is possible to prevent the focus size from being switched each time fluoroscopy is performed.

In addition, the X-ray diagnostic apparatus 1 of the present embodiment provides the ratio of the estimated radiation dose to the upper limit of the radiation dose when the estimated imaging condition value for the second moving image capturing is used as the imaging condition for the second moving image capturing, and , and the ratio of the estimated exposure dose to the upper limit value of the exposure dose when the estimated imaging conditions for the third moving image capturing are used as the imaging conditions for the third moving image capturing. Further, the size of the X-ray focal point in the first moving image capturing is the first focal size, the imaging condition estimated value in the second moving image capturing is larger than the determination value, and the ratio in the second moving image capturing is larger than the dose determination value, the first focus size is determined as the size of the X-ray focus in the second video imaging. Further, the size of the X-ray focal point in the second moving image capturing is the first focal size, the imaging condition estimated value in the third moving image capturing is larger than the determination value, and the ratio in the third moving image capturing is larger than the dose determination value, the first focus size is determined as the size of the X-ray focus in the third moving image capturing.

In summary, the X-ray diagnostic apparatus 1 of the present embodiment, for example, has a small focus size in fluoroscopy with the number of fluoroscopy times of N−1, the tube voltage estimated value Vp1 in fluoroscopy with the number of fluoroscopy times of N is larger than the threshold value Vth1, and , if the exposure limit attainment index R is equal to or less than the threshold value β, the focus size in fluoroscopy with the number of fluoroscopy times N is determined to be a medium focus, the focus size in fluoroscopy with the number of fluoroscopy times N−1 is a small focus, and the focus size in fluoroscopy with the number of fluoroscopy times N is When the tube voltage estimated value Vp1 is greater than the threshold Vth1 and the exposure limit attainment index R is greater than the threshold β, the focus size in the fluoroscopy of the number N of fluoroscopy is determined to be a small focus.

Therefore, in the X-ray diagnostic apparatus 1 of the present embodiment, when a small focus is used in the previous fluoroscopy, the contrast of the X-ray image generated in the next fluoroscopy is low, and a medium focus is used as the focal size. The next focus size is switched to the medium focus only when a sufficient margin of predicted exposure dose is ensured for the exposure limit in the case of use. On the other hand, even if the contrast of the X-ray image generated in the next fluoroscopy is low, the X-ray diagnostic apparatus 1 of the present embodiment does not provide sufficient margin for the predicted exposure dose with respect to the exposure limit. Do not switch next focus size to medium focus.

That is, with the above configuration and operation, according to the X-ray diagnostic apparatus 1 of the present embodiment, the focal size is set to the medium focal point where the exposure dose of the subject increases only when a certain or more allowance for the exposure dose is ensured. switch. As a result, it is possible to reliably prevent the exposure dose to the subject from exceeding the exposure limit in the next fluoroscopy.

(Second embodiment)
A second embodiment will be described. This embodiment is obtained by modifying the configuration of the first embodiment as follows. In the present embodiment, part of the imaging condition setting processing executed by the processing circuit 44 by the imaging condition setting function 442 is different from the first embodiment. In this embodiment, processing circuitry 44 uses the tube current estimate instead of the tube voltage estimate to determine the focal spot size in the next fluoroscopy. Descriptions of the same configurations, operations, and effects as in the first embodiment are omitted.

The operation of the imaging condition setting process executed by the X-ray diagnostic apparatus 1 will be described below. FIG. 4 is a flowchart showing an example of the procedure of imaging condition setting processing executed by the X-ray diagnostic apparatus 1 according to this embodiment. The processes of steps S131 to S136, steps S138 to S140, and steps S142 to S143 in FIG. Since it is the same as the processing, the explanation is omitted.

(imaging condition setting process)
(Step S137)
The processing circuit 44 determines whether or not the estimated tube current value Ip1 is equal to or less than the threshold value Ith1. The threshold Ith1 is a value for determining whether the contrast of the generated X-ray image satisfies a predetermined condition. The threshold Ith1 is, for example, a value determined from the range of 50 to 200 mA. A predetermined value may be set as the threshold value Ith1, or may be input by the operator for each examination. The threshold Ith1 is an example of a determination value. Also, the threshold Ith1 is an example of a first value. If the tube current estimated value Ip1 is less than or equal to the threshold value Ith1 (step S137-Yes), the process proceeds to step S138. If the estimated tube current value Ip1 is not less than or equal to the threshold value Ith1 (step S137—No), that is, if the estimated tube current value Ip1 is greater than the threshold value Ith1, the process proceeds to step S139.

(Step S141)
The processing circuit 44 determines whether or not the estimated tube current value Ip1 is equal to or less than the threshold value Ith2. The threshold Ith2 is smaller than the threshold Ith1 by a set value α2. That is, Ith2=Ith1-α2. The set value α2 is, for example, a value determined from the range of 5 to 20 mA. The set value α2 may be set to a predetermined value, or may be input by the operator for each examination. The threshold Ith2 is an example of a determination value. Also, the threshold Ith2 is an example of a second value. If the tube current estimated value Ip1 is less than or equal to the threshold value Ith2 (step S141-Yes), the process proceeds to step S122. If the estimated tube current value Ip1 is not less than or equal to the threshold value Ith2 (step S141-No), that is, if the estimated tube current value Ip1 is greater than the threshold value Ith2, the process proceeds to step S123.

The effects of the X-ray diagnostic apparatus 1 according to this embodiment will be described below.

For example, the X-ray diagnostic apparatus 1 of the present embodiment calculates an estimated tube current value Ip1 for N fluoroscopy based on the X-ray conditions for N−1 fluoroscopy, and based on the tube current estimated value Ip1 Determine the focal spot size in N fluoroscopy, calculate the estimated tube voltage Vp1 in N+1 fluoroscopy based on the output of the X-ray conditions in N fluoroscopy, and perform fluoroscopy based on the estimated tube voltage Vp1 Determine the focal spot size in N+1 perspectives.

Therefore, the X-ray diagnostic apparatus 1 of the present embodiment performs the following operations in accordance with the operation of the input interface 43 based on the output of the X-ray detector 13 in the fluoroscopy performed immediately before in response to the operation of the input interface 43 . Determines the focal spot size in fluoroscopy performed in Therefore, in the X-ray diagnostic apparatus 1 of this embodiment as well, the same effects as those of the first embodiment can be obtained.

(Third embodiment)
A third embodiment will be described. This embodiment is obtained by modifying the configuration of the first embodiment as follows. In the present embodiment, part of the imaging condition setting processing executed by the processing circuit 44 by the imaging condition setting function 442 is different from the first embodiment. In this embodiment, processing circuitry 44 uses the pulse width estimate instead of the tube voltage estimate to determine the focal spot size in the next fluoroscopy. Descriptions of the same configurations, operations, and effects as in the first embodiment are omitted.

The operation of the imaging condition setting process executed by the X-ray diagnostic apparatus 1 will be described below. FIG. 5 is a flowchart showing an example of the procedure of imaging condition setting processing executed by the X-ray diagnostic apparatus 1 according to this embodiment. The processes of steps S151 to S156, steps S158 to S160, and steps S162 to S163 in FIG. Since it is the same as the processing, the explanation is omitted.

(imaging condition setting process)
(Step S157)
The processing circuit 44 determines whether or not the pulse width estimated value Wp1 is equal to or less than the threshold value Wth1. The threshold Wth1 is a value for determining whether the contrast of the generated X-ray image satisfies a predetermined condition. The threshold Wth1 is, for example, a value determined from a range of 10-20 ms. A predetermined value may be set as the threshold Wth1, or may be input by the operator for each examination. Threshold Wth1 is an example of a determination value. Also, the threshold Wth1 is an example of a first value. If the pulse width estimated value Wp1 is equal to or less than the threshold value Wth1 (step S157-Yes), the process proceeds to step S158. If the estimated pulse width value Wp1 is not less than or equal to the threshold value Wth1 (step S157-No), that is, if the estimated pulse width value Wp1 is greater than the threshold value Wth1, the process proceeds to step S160.

(Step S161)
The processing circuit 44 determines whether or not the pulse width estimated value Wp1 is equal to or less than the threshold value Wth2. The threshold Wth2 is smaller than the threshold Wth1 by a set value α3. That is, Wth2=Wth1-α3. The set value α3 is, for example, a value determined from a range of 3 to 5 ms. A predetermined value may be set as the set value α3, or may be input by the operator for each examination. Threshold Wth2 is an example of a determination value. Also, the threshold Wth2 is an example of a second value. If the estimated pulse width value Wp1 is equal to or smaller than the threshold value Wth2 (step S161-Yes), the process proceeds to step S162. If the estimated pulse width value Wp1 is not less than or equal to the threshold value Wth2 (step S161-No), that is, if the estimated pulse width value Wp1 is greater than the threshold value Wth2, the process proceeds to step S163.

The effects of the X-ray diagnostic apparatus 1 according to this embodiment will be described below.

For example, the X-ray diagnostic apparatus 1 of the present embodiment calculates the pulse width estimated value Wp1 in fluoroscopy for the number of fluoroscopy times N based on the X-ray conditions for fluoroscopy for the number of fluoroscopy times N−1, and based on the tube current estimated value Ip1 Determine the focal spot size in N fluoroscopy, calculate the pulse width estimated value Wp1 in N+1 fluoroscopy based on the output of the X-ray conditions in N fluoroscopy, and perform fluoroscopy based on the tube voltage estimated value Vp1 Determine the focal spot size in N+1 perspectives.

Therefore, the X-ray diagnostic apparatus 1 of the present embodiment performs the following operations in accordance with the operation of the input interface 43 based on the output of the X-ray detector 13 in the fluoroscopy performed immediately before in response to the operation of the input interface 43 . Determines the focal spot size in fluoroscopy performed in Therefore, in the X-ray diagnostic apparatus 1 of this embodiment as well, the same effects as those of the first embodiment can be obtained.

(Fourth embodiment)
A fourth embodiment will be described. This embodiment is obtained by modifying the configuration of the first embodiment as follows. In the present embodiment, part of the imaging condition setting processing executed by the processing circuit 44 by the imaging condition setting function 442 is different from the first embodiment. In this embodiment, processing circuitry 44 uses the AGC magnification estimate instead of the tube voltage estimate to determine the focal spot size in the next fluoroscopy. Descriptions of the same configurations, operations, and effects as in the first embodiment are omitted.

The operation of the imaging condition setting process executed by the X-ray diagnostic apparatus 1 will be described below. FIG. 6 is a flowchart showing an example of the procedure of imaging condition setting processing executed by the X-ray diagnostic apparatus 1 according to this embodiment. The processes of steps S171 to S176, steps S178 to S180, and steps S182 to S183 in FIG. Since it is the same as the processing, the explanation is omitted.

(imaging condition setting process)
(Step S177)
The processing circuit 44 determines whether or not the AGC magnification estimated value Mp1 is less than or equal to the threshold value Mth1. The threshold Mth1 is a value for determining whether noise in the generated X-ray image satisfies a predetermined condition. The threshold Mth1 is, for example, a value determined from the range of 110% to 200%. A predetermined value may be set as the threshold Mth1, or may be input by the operator for each examination. Threshold Mth1 is an example of a determination value. Also, the threshold Mth1 is an example of a first value. If the AGC magnification estimated value Mp1 is less than or equal to the threshold value Mth1 (step S177-Yes), the process proceeds to step S178. If the AGC magnification estimated value Mp1 is not less than or equal to the threshold value Mth1 (step S177-No), that is, if the AGC magnification estimated value Mp1 is greater than the threshold value Mth1, the process proceeds to step S179.

(Step S181)
The processing circuit 44 determines whether or not the AGC magnification estimated value Mp1 is equal to or less than the threshold value Mth2. The threshold Mth2 is smaller than the threshold Mth1 by a set value α4. That is, Mth2=Mth1-α4. The set value α4 is, for example, a value determined from a range of 5 to 20%. A predetermined value may be set as the set value α4, or may be input by the operator for each examination. Threshold Mth2 is an example of a determination value. Also, the threshold Mth2 is an example of a second value. If the AGC magnification estimated value Mp1 is less than or equal to the threshold value Mth2 (step S181-Yes), the process proceeds to step S182. If the AGC magnification estimated value Mp1 is not less than or equal to the threshold value Mth2 (step S181-No), that is, if the AGC magnification estimated value Mp1 is greater than the threshold value Mth2, the process proceeds to step S183.

The effects of the X-ray diagnostic apparatus 1 according to this embodiment will be described below.

For example, the X-ray diagnostic apparatus 1 of the present embodiment calculates an estimated AGC magnification value Mp1 for fluoroscopy for the number of times of fluoroscopy (N−1) based on the X-ray conditions for fluoroscopy for the number of times of fluoroscopy (N−1), and based on the estimated AGC magnification value Mp1 Determine the focal size in fluoroscopy for the number of times of N fluoroscopy, calculate the AGC magnification estimated value Mp1 for the fluoroscopy for the number of times of fluoroscopy of N+1 based on the output of the X-ray conditions in the fluoroscopy for the number of times of N, and fluoroscopy based on the AGC magnification estimated value Mp1 Determine the focal spot size in N+1 perspectives.

That is, with the above configuration and operation, according to the X-ray diagnostic apparatus 1 of the present embodiment, based on the output of the X-ray detector 13 in the previous fluoroscopy, the next fluoroscopy executed by depressing the foot switch again. can be determined. Therefore, in the next fluoroscopy, the focus size can be set according to the X-ray conditions in the previous fluoroscopy. Therefore, even if the thickness of the subject changes during the previous fluoroscopy run, which changes the focal spot size appropriate for generating an X-ray image where the noise satisfies the predetermined criteria, the feedback control provides feedback control. Based on the X-ray conditions controlled to appropriate values according to the thickness of the subject, the appropriate focal spot size in the next fluoroscopy can be automatically set. This improves the quality of the X-ray image produced in the next fluoroscopy.

Further, for example, in the process of step S181, the X-ray diagnostic apparatus 1 of the present embodiment reduces the focal size in the fluoroscopy of the number of times N of fluoroscopy when the AGC magnification estimated value Mp1 in the fluoroscopy of the number of times of fluoroscopy of N is equal to or smaller than the threshold value Mth2. If the focal point is determined and the AGC magnification estimated value Mp1 in the fluoroscopy of the number of times of fluoroscopy of N is larger than the threshold value Mth2, the focal size of the fluoroscopy of the number of times of fluoroscopy of N is decided to be the middle focus.

For example, if the maximum x-ray tube power output fails to produce an x-ray image above a given brightness, the thickness of the subject may increase during the previous fluoroscopy run using a medium focus size. As it becomes smaller, the AGC magnification required to generate an X-ray image with a predetermined brightness or higher becomes smaller. In such a case, according to the X-ray diagnostic apparatus 1 of the present embodiment, the AGC magnification estimated value Mp1 at the small focus becomes equal to or smaller than the threshold Mth2, and the focal size in the next fluoroscopy is set to the small focus. As a result, when the output of the X-ray tube has a margin, that is, when an X-ray image with a predetermined brightness and low noise can be generated even when a small focus with a small output is used, By setting the focus size in the next fluoroscopy to a small focus, an X-ray image with higher resolution can be generated than when the focus size is set to a medium focus.

Also, for example, if an X-ray image with a predetermined brightness or higher cannot be generated even with the maximum output of the X-ray tube, the subject's image during the previous fluoroscopy using the small focus size As the thickness increases, the AGC magnification required to generate an X-ray image with a predetermined brightness or higher increases, resulting in increased noise in the generated X-ray image. In such a case, according to the X-ray diagnostic apparatus 1 of the present embodiment, the estimated AGC magnification Mp1 at the small focus becomes larger than the threshold Mth2, and the focal size in the next fluoroscopy is set to the middle focus. Therefore, in the next fluoroscopy, the focus size is switched to the middle focus that can increase the output of the X-ray tube compared to the small focus, thereby securing the necessary dose and suppressing the AGC magnification. can be done. Therefore, it is possible to secure the brightness of the X-ray image and generate an X-ray image with less noise than when the small focus size is continuously used.

(Modified Examples of First to Fourth Embodiments)
Note that the imaging condition setting process executed in step S101 is executed during moving image imaging in fluoroscopy, and the focus size in the next fluoroscopy is determined based on the current imaging conditions in the fluoroscopy being executed. Then, the focus size is switched based on the focus size determined in the imaging condition setting process from the end of the current fluoroscopy to the start of the next fluoroscopy. In this case, the fluoroscopy being performed corresponds to the first moving image capturing or the second moving image capturing, and the fluoroscopy performed next to the fluoroscopy being performed corresponds to the second moving image capturing or the third moving image capturing. do.

In addition, in the processes of steps S117, S137, S157, and S177, the medium-focus imaging condition estimated value may be used instead of the small-focus imaging condition estimated value. An imaging condition estimated value in the case of using another different focal size may be used. Similarly, in the processing in steps S121, S141, S161, and S181, instead of the small focus imaging condition estimated value, the intermediate focus imaging condition estimated value may be used. may use an imaging condition estimated value in the case of using another different focal size.

Note that, for example, when fluoroscopy is performed in the first imaging mode with a small focus size and high resolution, the X-ray tube is more efficient than when fluoroscopy is performed in a second imaging mode with a large focus size and a low resolution. Since the output upper limit becomes smaller, the output of the X-ray tube easily reaches the maximum output. Therefore, even if the thickness of the subject changes during execution of the immediately preceding fluoroscopy, the tube voltage estimated value is less likely to change. Therefore, the type of imaging condition estimated value used for determination may be selected according to the resolution of the X-ray image generated in the next fluoroscopy. For example, when generating an X-ray image of a first resolution, as in the fourth embodiment, the AGC magnification estimation value is used to select the focus size in the next fluoroscopy, and the first resolution In the case of generating an X-ray image with a resolution higher than that, the estimated tube voltage value may be used to select the focus size in the next fluoroscopy as in the first embodiment. The resolution of the X-ray image to be generated in the next fluoroscopy may be obtained, for example, by inputting the setting of the imaging mode by the operator, or may be automatically obtained from the memory 41 or the like.

It should be noted that the focal spot size may also be switched by controlling a control grid electrode that can continuously adjust the focal spot size. In this case, the X-ray generator 12 is a grid-controlled discharge tube having an anode, a cathode, and a control grid electrode, and the tube may have only one filament. The processing circuit 44 determines the value of the next focus size in the next fluoroscopy by the imaging condition setting function 442 . Then, the processing circuit 44 controls the control grid electrodes by the X-ray control function 444 based on the determined size of the focal point of the X-ray. Specifically, processing circuitry 44 controls the control grid electrodes such that the focal spot size is the determined value.

The “output of the X-ray detector” used for determining the size of the focal point of the X-ray by the imaging condition setting function 442 means that some or all of the pixels of the X-ray detector 13 are collectively non-destructively read out. Any information other than an X-ray image can be used as long as it reflects the dose of X-rays detected by an X-ray detector, such as the result of the detection (that is, a signal corresponding to the total accumulated charge of some or all of the pixels). good.

According to at least one embodiment described above, an appropriate focus size can be set automatically.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 1... X-ray diagnostic apparatus 10... Imaging apparatus 11... High-voltage generator 12... X-ray generator 13... X-ray detector 14... C-arm 142... C-arm drive device 15... X-ray generator 30... Bed apparatus 31... Base 32 Bed drive device 33 Top plate 34 Support frame 40 Console device 41 Memory 42 Display 43 Input interface 44 Processing circuit 441 System control function 442 Imaging condition setting function 443 Drive control function 444 X-ray control function 445 Image generation function 446 Display control function Vp1 Estimated tube voltage value Vp2 Estimated tube voltage value Ip1 Estimated tube current value Ip2 Estimated tube current value Wp1 Estimated pulse width value Wp2 Estimated pulse width Value Mp1: Estimated AGC magnification value Mp2: Estimated AGC magnification value Vth1, Vth2, Ith1, Ith2, Wth1, Wth2, Mth1, Mth2, β: Threshold value α1, α2, α3, α4: Set value R: Exposure limit reach index

Claims (14)

an X-ray tube for generating X-rays;
an X-ray detector that detects X-rays emitted from the X-ray tube;
an operation unit for instructing imaging of a moving image using the X-ray tube and the X-ray detector;
an X-ray condition determination unit that determines conditions for X-ray irradiation by the X-ray tube;
with
The X-ray condition determining unit,
During the execution of the first moving image capturing performed in response to the operation of the operation unit and the second moving image capturing performed in response to the operation of the operation unit after the first moving image capturing, Based on the output of the X-ray detector in the frame, performing control to set at least one of the X-ray irradiation conditions and the gain applied to the X-ray image in the subsequent frame,
determining the focal size of the X-ray in the second moving image capturing based on at least one of the X-ray irradiation conditions and the gain applied to the X-ray image in the first moving image capturing;
A third step executed in accordance with an operation to the operation unit after the second moving image capturing, based on at least one of the X-ray irradiation conditions and the gain applied to the X-ray image in the second moving image capturing. determining the size of the X-ray focal point in the video imaging of
X-ray diagnostic equipment. The X-ray condition determining unit,
Determining the focal size of the X-ray at the start of the second moving image capturing based on at least one of the X-ray irradiation conditions and the gain applied to the X-ray image at the end of the first moving image capturing death,
Determining the focal size of the X-ray at the start of the third moving image capturing based on at least one of the X-ray irradiation conditions and the gain applied to the X-ray image at the end of the second moving image capturing do,
The X-ray diagnostic apparatus according to claim 1. The X-ray condition determining unit,
When using a specific X-ray focal size for the second moving image capturing based on at least one of the X-ray irradiation conditions and the gain applied to the X-ray image in the first moving image capturing calculating an estimated imaging condition value that satisfies a condition related to a target output, determining the size of the focus of the X-ray in the second moving image capturing based on the estimated imaging condition value in the second moving image capturing;
calculating the imaging condition estimated value for the third moving image capturing based on at least one of the X-ray irradiation condition and the gain applied to the X-ray image in the second moving image capturing, and performing the third moving image capturing; determining the size of the focus of the X-ray in the third video imaging based on the imaging condition estimated value in
3. The X-ray diagnostic apparatus according to claim 1 or 2. The X-ray condition determining unit,
setting a first focal size as the focus size of the X-rays in the second moving image capturing, when the imaging condition estimated value in the second moving image capturing is equal to or less than a judgment value; determining a second focal size larger than the first focal size as the focal size of the X-ray in the second moving image imaging when the imaging condition estimated value in imaging is greater than the determination value;
If the imaging condition estimated value in the third moving image capturing is equal to or less than the determination value, the first focus size is set as the focus size of the X-ray in the third moving image capturing, and the third When the imaging condition estimated value in the moving image capturing is larger than the determination value, determining the second focus size as the focus size of the X-ray in the third moving image capturing,
The X-ray diagnostic apparatus according to claim 3. The X-ray condition determining unit,
when the focal size of the X-ray in the first moving image capturing is the first focal size, the focal size of the X-ray in the second moving image capturing using the first value as the determination value; is determined, and when the size of the focal point of the X-ray in the first moving image capturing is the second focal size, the second value different from the first value is used as the determination value, and the second Determining the size of the focus of the X-ray in moving image imaging of
When the size of the focal point of the X-ray in the second moving image capturing is the first focal size, the size of the focal point of the X-ray in the third moving image capturing using the first value as the determination value is determined, and when the size of the X-ray focus in the second moving image capturing is the second focus size, the second value is used as the determination value, and the X in the third moving image capturing determine the size of the focus of the line,
The X-ray diagnostic apparatus according to claim 4. 6. The X-ray diagnostic apparatus of claim 5, wherein said second value is less than said first value. The X-ray condition determining unit,
A ratio of the estimated radiation dose to an upper limit value of the radiation dose when the estimated imaging condition value in the second moving image capturing is used as the imaging condition in the second moving image capturing, and the imaging in the third moving image capturing further calculating a ratio of the estimated radiation dose to the upper limit of the radiation dose when the conditional estimated value is used as the imaging condition in the third moving image imaging;
The X-ray focus size in the first moving image capturing is the first focus size, and the imaging condition estimated value in the second moving image capturing is larger than the determination value, and the second moving image capturing is performed. If the ratio in video imaging is smaller than the dose determination value, determining the second focus size as the size of the X-ray focus in the second video imaging,
The focal size of the X-ray in the second moving image capturing is the first focal size, and the imaging condition estimated value in the third moving image capturing is larger than the determination value, and the third If the ratio in video imaging is smaller than the dose determination value, the second focus size is determined as the size of the X-ray focus in the third video imaging,
7. The X-ray diagnostic apparatus according to any one of claims 4-6. The imaging condition estimated values include a tube voltage estimated value satisfying the conditions regarding the target output, a tube current estimated value satisfying the conditions regarding the target output, a pulse width estimated value satisfying the conditions regarding the target output, and the target. 8. An X-ray diagnostic apparatus according to any one of claims 3 to 7, comprising at least one AGC magnification estimate that satisfies said condition for output. The X-ray condition determining unit,
X-ray focus size, tube voltage, tube current and pulse width, AGC magnification, and filter obtained based on at least one of the X-ray irradiation conditions and the gain applied to the X-ray image in the first moving image imaging calculating the imaging condition estimated value in the second moving image imaging based on the specific information;
X-ray focus size, tube voltage, tube current and pulse width, AGC magnification, and filter obtained based on at least one of the X-ray irradiation conditions and the gain applied to the X-ray image in the second moving image imaging calculating the imaging condition estimated value in the third moving image imaging based on the specific information;
An X-ray diagnostic apparatus according to any one of claims 3 to 8. The X-ray condition determining unit,
For each of a plurality of focus sizes with different X-ray focus sizes, the imaging condition estimated value in the second moving image capturing is calculated, and corresponds to the focus size determined as the X-ray focus size. determining the imaging condition estimated value as an imaging condition in the second moving image imaging;
For each of a plurality of focal sizes with different X-ray focal sizes, the imaging condition estimated value in the third moving image imaging is calculated, and corresponds to the focal size determined as the X-ray focal size. determining the imaging condition estimated value as an imaging condition in the third moving image imaging;
An X-ray diagnostic apparatus according to any one of claims 3 to 9. An X-ray controller that selects a filament to be used from a plurality of filaments provided in a bulb of the X-ray tube based on the size of the X-ray focal point determined by the X-ray condition determination unit. X-ray diagnostic apparatus according to any one of claims 1 to 10. a control grid electrode capable of adjusting the focal size of the X-rays generated from the X-ray tube; and the control grid based on the focal size of the X-rays determined by the X-ray condition determining unit an X-ray control unit that controls the electrodes;
11. The X-ray diagnostic apparatus of any one of claims 1-10, further comprising: The X-ray condition determining unit,
Based on the X-ray image generated based on at least one of the X-ray irradiation conditions and the gain applied to the X-ray image in the first moving image capturing, the focal point of the X-ray in the second moving image capturing determine the size of
Based on the X-ray image generated based on at least one of the X-ray irradiation conditions and the gain applied to the X-ray image in the second moving image capturing, the focal point of the X-ray in the third moving image capturing determine the size of
X-ray diagnostic apparatus according to any one of claims 1 to 12 . The X-ray condition determining unit,
determining the focal size of the X-ray in the second moving image capturing based on the completion of the first moving image capturing;
Determining the size of the focus of the X-ray in the third moving image capturing based on the completion of the second moving image capturing;
X-ray diagnostic apparatus according to any one of claims 1 to 13 .

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