JP2018130334A - X-ray diagnostic apparatus, control method of x-ray diagnostic apparatus, and image processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray diagnostic apparatus, a control method of the X-ray diagnostic apparatus, and an image processing apparatus in which the variation of an X-ray dose passing through an interested area in a subject can be suppressed.SOLUTION: An X-ray diagnostic apparatus concerning the present embodiment includes: an X-rays irradiation unit for making irradiation of X-rays toward a subject; an acquisition unit for repeatedly acquiring the X-ray image of the X-rays passing through the subject according to the irradiation of the X-rays irradiation unit; a setting unit for setting a first interested area being an area for use in control of the X-rays irradiation unit in the X-ray image; a generation unit for performing addition processing to apply and add the weight provided with the weighting value larger than 0 according to the position in the first interested area on each pixel value in the first interested area of the X-ray image according to acquisition of the X-ray image in the acquisition unit, and generating a control value based on the value obtained in the addition processing; and a control unit for controlling the X-rays irradiated by the X-rays irradiation unit so that the control value may come close to a predetermined value.SELECTED DRAWING: Figure 1

Description

  The present embodiment relates to an X-ray diagnostic apparatus, a control method for the X-ray diagnostic apparatus, and an image processing apparatus.

  In the X-ray diagnostic apparatus, X-ray fluoroscopy is performed in which X-ray images of X-rays transmitted through a subject are collected in time series, and X-ray images based on the X-ray images are obtained in time series. In this X-ray fluoroscopy, the X-ray dose is feedback controlled so that the pixel value in the first region of interest set in the X-ray image becomes a predetermined value.

  Pixels in the first region of interest set in the X-ray image are used for feedback control. Thereby, the X-ray dose is feedback-controlled so that the pixel value of the first region of interest in the X-ray image becomes a predetermined value. As a result, the region of interest in the subject in the image-processed X-ray image is displayed with a predetermined luminance value suitable for observation and diagnosis. Such control is called ABC (ABC: Auto Brightness Control).

  However, when body movement of the subject occurs, the pixel value distribution in the first region of interest set in the X-ray image fluctuates, and as a result of feedback control, the X-ray dose that passes through the region of interest in the subject fluctuates. There is a case. As a result, the luminance value in the region of interest in the subject also fluctuates and may not be suitable for observation or diagnosis.

JP-A-9-106016

  An object of the present embodiment is to provide an X-ray diagnostic apparatus, a control method for the X-ray diagnostic apparatus, and an image processing apparatus that can suppress fluctuations in X-ray dose that has passed through a region of interest within a subject.

  The X-ray diagnostic apparatus according to the present embodiment includes an X-ray irradiation unit that irradiates the subject with X-rays, and the X-ray of the X-ray that has passed through the subject in accordance with the irradiation of the X-ray irradiation unit. An acquisition unit that repeatedly acquires an image, a setting unit that sets a first region of interest, which is an area used for control of the X-ray irradiation unit, in the X-ray image, and acquisition of the X-ray image by the acquisition unit Accordingly, an addition process is performed in which each pixel value in the first region of interest of the X-ray image is added with a weight to which a weight value greater than 0 is given depending on the position in the first region of interest. A generation unit that generates a control value based on the value obtained by the addition process, and a control unit that controls the X-rays emitted by the X-ray irradiation unit so that the control value approaches a predetermined value; .

The block diagram for demonstrating the structure of the X-ray diagnostic apparatus which concerns on 1st Embodiment. The figure which shows the histogram of the image image-processed by the logarithmic conversion function. The figure which shows the time change of the control value which the production | generation function of the image processing apparatus produced | generated. The figure which shows an example of the setting table of the area | region and weight value which are set for every test | inspection classification. (A) is a figure which shows the range of the X-ray image of a chest front, and a 1st region of interest. (B) is a figure which shows the relationship between the weight value in each area | region of the 1st region of interest and 2nd region of interest in front of a chest, and the position in a 1st region of interest. (A) is a figure which shows the X-ray image of a thoracic vertebra front, and the range of a 1st region of interest. (B) is a figure which shows the relationship between the weight value in each area | region of the 1st region of interest of the thoracic vertebra front, and each 2nd region of interest, and the position in a 1st region of interest. (A) is a figure which shows the range of the X-ray image of the thoracic vertebra right side surface, and a 1st region of interest. (B) is a figure which shows the relationship between the weight value in each area | region of the 1st region of interest of the thoracic vertebra right side surface, and each 2nd region of interest, and the position in a 1st region of interest. (A) is a figure which shows the X-ray image of the left side surface of a thoracic vertebra, and the range of a 1st region of interest. (B) is a figure which shows the relationship between the weight value in each area | region of the 1st region of interest on the left side surface of a thoracic vertebra, and the 2nd region of interest, and the position in a 1st region of interest. The figure which shows the flowchart which showed a series of fluoroscopy flows concerning 1st Embodiment. It is a figure which shows the range of a 1st region of interest, a 2nd region of interest, and a 3rd region of interest, and is a figure which has a 2nd region of interest in the center part. It is a figure which shows the range of a 1st region of interest, a 2nd region of interest, and a 3rd region of interest, and a figure which has a 2nd region of interest in the right part. It is a figure which shows the range of a 1st region of interest, a 2nd region of interest, and a 3rd region of interest, and is a figure which has a 2nd region of interest in the left part. The figure which shows a weight value in case the weight value in a 1st region of interest changes continuously. The block diagram for demonstrating the structure of the X-ray diagnostic apparatus which concerns on 2nd Embodiment. (A) is a figure which shows the X-ray image seen in time series in the myelography of a lumbar vertebra. (B) is a figure showing the 1st region of interest and the 2nd region of interest which a setting function sets up in time series corresponding to an X-ray image. The figure which shows the flowchart which showed a series of flows in fluoroscopy using a fluoroscopy sequence setting function.

  Hereinafter, an X-ray diagnostic apparatus 10 according to an embodiment will be described 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 provided only when necessary.

(First embodiment)
First, the configuration of the X-ray diagnostic apparatus 10 according to the first embodiment will be described with reference to FIG. FIG. 1 is a block diagram for explaining a configuration of an X-ray diagnostic apparatus 10 according to the first embodiment. As shown in FIG. 1, the X-ray diagnostic apparatus 10 is an apparatus that can perform X-ray fluoroscopy of a subject P, and includes an X-ray irradiation apparatus 100, a collection apparatus 200, an image processing apparatus 300, and a control apparatus 400. And an exposure button 500, an input circuit 600, a display 700, and a top board 800.

  The X-ray irradiation apparatus 100 repeatedly irradiates X-rays toward the subject P at predetermined time intervals. This X-ray irradiation apparatus 100 includes a high voltage generator 102, an X-ray tube 104, and an X-ray movable diaphragm 106.

  The high voltage generator 102 outputs a tube voltage and a current based on the mAs value. The mAs value here is the product of the tube current and the irradiation time. Specifically, the high voltage generator 102 includes, for example, a transformer and a rectifier. The transformer is connected to an AC power source, and boosts an AC voltage supplied from the AC power source according to a set tube voltage. The transformer then supplies the boosted AC voltage to the rectifier. The rectifier rectifies the AC voltage supplied from the transformer and outputs a pulsating voltage having only a positive component as a tube voltage. The high voltage generator 102 divides the pulsating voltage and outputs a current based on the mAs value during the irradiation time based on the mAs value. The current based on this mAs value corresponds to the tube current.

  More specifically, the high voltage generator 102 is connected to the control device 400 and the X-ray tube 104, and a fluoroscopic condition signal indicating the tube voltage, tube current, pulse width, and pulse rate is generated from the control device 400. Is input to the device 102. The high voltage generator 102 supplies a tube voltage based on the fluoroscopic condition signal and a current corresponding to the tube current to the X-ray tube 104 at a time interval that is a reciprocal of the pulse rate during the pulse width based on the fluoroscopic condition signal. That is, the time interval here means the time from the start of X-ray irradiation to the start of the next X-ray irradiation. This continues as long as the exposure button 500 is pressed. Note that the time interval in this embodiment may be the reciprocal of the pulse rate, or may be the time from the end of X-ray irradiation to the start of the next X-ray irradiation.

  The X-ray tube 104 generates X-rays. The X-ray tube 104 has a filament serving as a cathode and a target metal serving as an anode in a vacuum envelope. The X-ray tube 104 is connected to the high voltage generator 102, and a current corresponding to the tube voltage and the tube current is supplied from the high voltage generator 102. More specifically, the filament is formed in a coil shape from a metal such as tungsten, and generates a thermoelectron when a current corresponding to the tube current is supplied from the high voltage generator 102. That is, the number of thermoelectrons generated per unit time is the tube current. The target metal is, for example, tungsten. A tube voltage supplied from the high voltage generator 102 is applied between the cathode and the anode, and an electric field is generated between the cathode and the anode. The thermoelectrons accelerated by this electric field collide with the target metal of the anode, and X-rays are generated from the target metal. As the tube voltage increases, the X-ray wavelength peak shifts to the short wavelength side, and the X-ray energy also increases.

  Here, the intensity of the X-ray is the energy of the X-ray passing through the unit area per unit time. Also. X-ray dose is the product of X-ray intensity and irradiation time. As can be seen from these, the X-ray dose is proportional to the mAs value and increases as the tube voltage increases.

  The X-ray movable diaphragm 106 has a wing-shaped diaphragm made of lead or the like. The X-ray movable diaphragm 106 is disposed at the exit of the X-ray tube 104 and is limited by moving the diaphragm of the X-ray irradiation range generated by the X-ray tube 104. Thereby, the range in which the subject P is irradiated with X-rays is limited. Here, the examiner manually moves the diaphragm before and during fluoroscopy. The movement of the diaphragm may be driven by a motor in accordance with a control signal from the control device 400.

  The collection apparatus 200 repeatedly collects X-ray images of X-rays that have passed through the subject P according to the irradiation of the X-ray irradiation apparatus 100. The collection apparatus 200 includes an X-ray detector 202, an AD conversion circuit 204, and an image correction unit 206. The X-ray detector 202 detects an X-ray image of X-rays transmitted through the subject P in units of pixels, and outputs an image signal proportional to the detected X-ray dose for each pixel. Here, the X-ray image is a two-dimensional X-ray intensity distribution.

  For example, the X-ray detector 202 is configured by a flat panel detector (FPD) for detecting X-rays irradiated on the detection surface. The FPD includes an image sensor, and a CMOS image sensor (Complementary Metal Oxide Image Sensor), a CCD (Charge Coupled Device), a thin film transistor (TFT), or the like is used as the image sensor.

  More specifically, the X-ray detector 202 is connected to the control device 400 and controlled according to, for example, an accumulation signal and an irradiation time signal input from the control device 400. Further, the driving of the X-ray detector 202 is synchronized with the fluoroscopic condition signal input to the high voltage generator 102. For example, in a CMOS image sensor, a photodiode (PD: Photodiode) corresponding to each pixel stores a charge corresponding to an X-ray dose while X-rays are irradiated from the X-ray tube 104 in accordance with an accumulation signal. Then, according to the irradiation time signal, the photodiode corresponding to each pixel converts the stored charge into a voltage at the end of the irradiation time, and outputs the voltage signal amplified by the amplifier as an analog image signal. .

  The AD conversion circuit 204 converts an analog signal into a digital signal. More specifically, the AD conversion circuit 204 is connected to the X-ray detector 202 and the image processing apparatus 300, and converts an analog image signal input from the X-ray detector 202 into a digital image signal.

  The image correction circuit 206 is connected to the AD conversion circuit 204, and for digital image signals, gain correction processing for correcting non-uniform sensitivity of each pixel in the X-ray detector 202, and defective pixel correction for correcting pixel omission. A correction process such as a process is performed to generate an X-ray image after the correction process. The image correction circuit 206 outputs the X-ray image after the correction process to the first storage circuit 302 of the image processing apparatus 300. In the present embodiment, an image based on a two-dimensional intensity distribution of X-rays transmitted through the subject P is referred to as an X-ray image. For example, the X-ray image includes an X-ray digital image based on a digital image signal output from the AD conversion circuit 204. An X-ray image also includes an image obtained by performing correction processing such as gain correction processing and defective pixel correction processing on this X-ray digital image.

  The image processing apparatus 300 processes an X-ray image based on the X-ray image collected by the collection apparatus 200 and generates a control value for performing dose control of the X-rays irradiated by the X-ray irradiation apparatus 100. In addition, the image processing apparatus 300 performs image processing on the X-ray image and generates an image for display. Specifically, the image processing apparatus 300 includes a first storage circuit 302 and a processing circuit 304. The first storage circuit 302 has a configuration including a readable recording medium such as a magnetic or optical recording medium or a semiconductor memory. The first storage circuit 302 stores each processing function performed by the processing circuit 304 in the form of a program that can be executed by a computer. The first storage circuit 302 stores the X-ray image input from the image correction circuit 206, and also stores area information and weight values for realizing each processing function in the processing circuit 304 described later. More specifically, the first storage circuit 302 is connected to the image correction circuit 206 of the collection device 200 and stores the X-ray image input from the image correction circuit 206.

  The processing circuit 304 is a processor that implements each processing function corresponding to each program by reading and executing the program from the first storage circuit 302. In other words, the processing circuit 304 in a state where each program is read has each processing function. In FIG. 1, each processing function is described as being realized by a single processing circuit 304. However, the processing circuit 304 is configured by combining a plurality of independent processors, and each processor executes a program. Each processing function may be realized.

  More specifically, the processing circuit 304 is connected to the image correction circuit 206 of the acquisition device 200, the first storage circuit 302, the control device 400, the display 700, and the like, and is read out from the first storage circuit 302. , And outputs the processing result to the control device 400 and the display 700. That is, the processing circuit 304 includes a pixel value conversion function 306, a setting function 308, a generation function 310, an image processing function 312, and a first gradation processing function 314. Here, the pixel value conversion function 306, the setting function 308, and the generation function 310 are functions for calculating control values used for controlling the X-ray irradiation apparatus 100. On the other hand, the image processing function 312 and the first gradation processing function 314 are functions used to perform image processing on an X-ray image and generate an image for display.

  The pixel value conversion function 306 converts the pixel value of the X-ray image read from the first storage circuit 302. The pixel value conversion function 306 has a pixel value conversion table, and converts the pixel value of the X-ray image based on the conversion table.

  Here, the pixel value conversion function 306 will be described with reference to FIG. FIG. 2 is a diagram illustrating a histogram of an X-ray image that has been subjected to image processing by logarithmic conversion, which is an example of the pixel value conversion function 306. The left figure shows a thoracic vertebra front image and a first region of interest 320 described later, the middle figure is a histogram of pixel values in the first region of interest before logarithmic transformation, and the right figure shows a logarithmic transformation. It is the histogram of the pixel value in the 1st region of interest 320 after having performed. In the histogram, the horizontal axis indicates the pixel value, and the vertical axis indicates the appearance frequency for each pixel value.

  The pixel value conversion by the pixel value conversion function 306 is performed so as to expand a portion where the luminance is desired to be matched and compress the other portion. For example, when it is desired to adjust the brightness to the mediastinum in the chest examination shown in the left diagram of FIG. Conversion is performed. As a result, a region close to a lower pixel value (mediastinum) has a luminance suitable for observation. Note that the high pixel value region (lung field) is bright and difficult to observe, but is a region with a large dose and low noise, so that it can be observed by correcting with existing techniques such as dynamic range compression processing. As described above, when logarithmic conversion is used for the pixel value conversion function 306 and an existing correction technique such as dynamic range compression processing is used in combination, a wide range can be observed. Logarithmic transformation is suitable for ABC applications.

  Returning to FIG. 1 again, the setting function 308 sets a first region of interest, which is an area used for control of the X-ray irradiation apparatus 100, in an X-ray image based on the X-ray image. Here, the X-ray image is an image whose pixel value is converted by the pixel value conversion function 306. An image obtained by performing various kinds of image processing on an image based on an X-ray dose transmitted through the subject P is also referred to as an X-ray image. For example, an image obtained by performing image processing such as pixel value conversion and frequency processing on an X-ray image is also referred to as an X-ray image.

  The setting function 308 sets the second region of interest within the first region of interest. Details of the setting function 308 will be described later. Note that the region of interest may be referred to as ROI (ROI: Region Of Interest).

  The generation function 310 performs an addition process of adding each pixel value in the first region of interest of the X-ray image with a weight to which a weight value greater than 0 is given according to the position in the first region of interest. A control value for controlling the X-ray irradiation apparatus 100 is generated based on the value obtained by the addition process. Details of the generation function 310 will also be described later.

The image processing function 312 performs sharpening processing such as frequency processing on the X-ray image after the correction processing.
The first gradation processing function 314 selects one of gradations among the X-ray image generated by the image processing function 312, the image read from the first storage circuit 302, and the X-ray image generated by the pixel value conversion function 306. A first gradation process for conversion is performed. Which image gradation processing the first gradation processing function 314 performs can be determined by a selection instruction from the input circuit 600, for example. Note that the pixel value conversion characteristics by the first gradation processing function 314 may be changed depending on the portion where the luminance is desired to be adjusted. For example, the pixel value conversion characteristics may be different between the chest examination and the limb examination.

  As shown in FIG. 1, the control device 400 includes a high voltage generator 102 of the X-ray irradiation device 100, an X-ray detector 202 of the collection device 200, a processing circuit 304 of the image processing device 300, and an exposure button 500. The input circuit 600 and the display 700 are connected to control the entire X-ray diagnostic apparatus 1. Specifically, the control device 400 includes a second memory circuit 402, an F condition determination circuit 404, and a control circuit 406.

  Similar to the first storage circuit 302 described above, the second storage circuit 402 includes a readable recording medium such as a magnetic or optical recording medium or a semiconductor memory. The second storage circuit 402 stores each processing function performed by the control circuit 406 in the form of a program that can be executed by a computer. The second storage circuit 402 stores a dose index, which is an index of the X-ray dose that has passed through the subject P, for each examination type, and stores an F condition determination table 408 shown in FIG. In the F condition determination table 408, the horizontal axis indicates the tube voltage (F_kV), and the vertical axis indicates the mAs value (F_mAs) that is the product of the tube current and the pulse width. FIG. 1 shows a combination of the tube voltage (F_kV) and the mAs value (F_mAs) at which the X-ray dose becomes larger according to the direction indicated by the arrow 410 in FIG.

  The F condition determination circuit 404 uses the control circuit 406 to calculate the tube voltage and the mAs value, which are the fluoroscopic conditions in the next fluoroscopy, based on the dose index corresponding to the examination type and the control value generated by the generation function 310 of the image processing apparatus 300. Output to.

  The control circuit 406 is a processor that implements each function corresponding to each program by reading the program from the second storage circuit 402 and executing the program. More specifically, the control circuit 406 is connected to the high voltage generator 102 of the X-ray irradiation apparatus 100 and the F condition determination circuit 404, and the control value generated by the generation function 310 for the dose index determined by the examination type. So that the tube voltage supplied to the X-ray tube 104 of the X-ray irradiation apparatus 100 and the current and pulse width corresponding to the mAs value are controlled. That is, the control circuit 406 outputs a fluoroscopy condition signal based on the tube voltage and the mAs value input from the F condition determination circuit 404 to the high voltage generator 102. Details of a series of fluoroscopic processes performed by the control circuit 406 in the entire X-ray irradiation apparatus 100 will be described later with reference to FIG. Further, the control circuit 406 outputs a button indicating the examination type to the display 700 as a video signal for each examination type based on the examination type information read from the first storage circuit 302.

  The exposure button 500 is a switch for instructing the control device 400 about the X-ray irradiation timing, and the examiner operates the exposure button 500 by hand. The exposure button 500 is connected to the control circuit 406 of the control device 400 and outputs an exposure start signal to the control circuit 406 when the switch is pressed by the examiner.

  The input circuit 600 is realized by a trackball, a switch button, a mouse, a keyboard, and the like for setting an inspection type, a fluoroscopic inspection type, and the like. The input circuit 600 is connected to the control circuit 406 of the control device 400, converts the input operation received from the inspector into an electrical signal, and outputs it to the control circuit 406. In the present embodiment, when a signal indicating the inspection type is input from the input circuit 600 to the control circuit 406, the control circuit 406 starts an inspection of the inspection type. On the other hand, when a signal indicating another inspection type or an end signal indicating completion is input from the input circuit 600, the control circuit 406 ends the inspection of the inspection type.

  The display 700 is realized by a liquid crystal display device or the like for displaying an X-ray image. More specifically, the display 700 is connected to the processing circuit 304 of the image processing apparatus 300, and converts an X-ray image or the like processed by the processing circuit 304 into a luminance signal and displays it on the screen. The display 700 is connected to the control circuit 406, converts the video signal of the button indicating each examination type input from the control circuit 406 into a luminance signal and displays it on the screen as described above. For example, when a button indicating the examination type displayed on the display 700 is instructed to the examiner, a signal indicating the examination type is output from the input circuit 600 to the control circuit 406. On the other hand, when the instruction of the button indicating the examination type ends, an end signal indicating the end is output from the input circuit 600 to the control circuit 406.

  The top plate 800 is made of acrylic, carbon or the like having a high X-ray transmittance. The subject P in a lying state is placed on the top plate 800.

  Next, fluoroscopic condition control of the control circuit 406 used for ABC will be described based on FIG. 3 with reference to FIG. FIG. 3 is a diagram illustrating a time change of the control value 412 generated by the generation function 310 of the image processing apparatus 300. The horizontal axis indicates the elapsed time, and the vertical axis indicates the control value. As in FIG. 3, 412 in FIG. 3 indicates a control value when the examination type is chest front fluoroscopy, and 414 indicates a dose index serving as a reference for chest front fluoroscopy.

  As shown in FIG. 3, the control circuit 406 controls the fluoroscopic condition of the high voltage generator 102 in the X-ray irradiation apparatus 100 so that the control value 412 generated by the generation function 310 approaches the dose index 414. That is, when the control value 412 is larger than the dose index 414, the F condition determination circuit 404 reduces both the mAs value and the tube voltage of the fluoroscopy condition in the current fluoroscopy according to the F condition determination table 408, and Output. As a result, the control circuit 406 outputs the tube voltage for the fluoroscopy condition in the current fluoroscopy, the tube voltage for the next fluoroscopy in which the mAs value is reduced, and the mAs to the high voltage generator 102 as the fluoroscopy condition signal. That is, in the next fluoroscopy, the X-ray dose that passes through the subject decreases.

  On the other hand, when the control value 412 is smaller than the dose index 414, the F condition determination circuit 404 uses the F condition determination table 408 to increase both the mAs value of the fluoroscopy condition and the tube voltage in the current fluoroscopy. The tube voltage and mAs are output to the high voltage generator 102 as a fluoroscopic condition signal. That is, in the next fluoroscopy, the X-ray dose that passes through the subject increases. Note that the fluoroscopy conditions need not be changed to the next fluoroscopy, and may be changed after X-rays of several to several tens of pulses are irradiated.

  As can be seen from these, the control circuit 406 controls the high voltage generator 102 based on the input from the F condition determination circuit 404 so as to bring the control value 412 closer to the dose index 414 determined by the examination type. A series of controls for increasing or decreasing the X-ray dose so as to maintain the pixel value in the first region of interest in the X-ray image at a constant value is called ABC.

  Next, the setting function 308 and the generation function 310 will be described in more detail based on FIGS. 4 and 5A to 5D with reference to FIG. FIG. 4 is a diagram illustrating an example of a setting table of areas and weight values set for each examination type. In FIG. 4, the chest front, the lumbar front, the lumbar right side, and the lumbar left side are described as examples of examination types.

  Coordinate 1 is a coordinate indicating the first region of interest of the quadrangle, and indicates the coordinate of the origin in this quadrangle and the coordinate of the diagonal point connected to the origin by a diagonal line. The weight value 1 indicates the weight given to the region other than the second region of interest in the first region of interest. Here, the weight value corresponds to the value of the weight coefficient. This weight value may be normalized as shown in equation (1) described later. Coordinate 2 is a coordinate indicating the second region of interest of the quadrangle, and indicates the coordinate of the origin of the quadrangle and the coordinate of the diagonal point connected to the origin by a diagonal line. The weight value 2 indicates the weight given to the second region of interest. Note that two second regions of interest are set in front of the chest. Thus, the first region of interest and the second region of interest within the first region of interest are defined by the coordinates in the X-ray image.

  Here, the examination type is a protocol including a fluoroscopic part and a fluoroscopic direction in an examination such as a lumbar front, a lumbar side, a chest front, a head front, a chest side, an abdominal front, a hand front, and a foot front. The fluoroscopic part is a part of the body in the subject P. For example, the part is a lumbar vertebra, a chest, a head, an abdomen, a hand, a leg, or the like. Furthermore, the fluoroscopic direction is the direction of the subject P facing the traveling direction of the X-ray, and is, for example, the front surface, the back surface, the right side surface, or the left side surface. As described above, in the setting table stored in the first storage circuit 302, information on coordinates 1, weight values 1, coordinates 2, and weight values 2 is registered for each examination type that can be seen through.

  The shape of the first region of interest and the second region of interest is not limited to a quadrangle, and may be any shape. For example, a polygon such as an ellipse, a circle, a trapezoid, and a pentagon may be used.

  5A to 5D are diagrams illustrating the first region of interest 320, the range of the second region of interest 322, the region of interest 324 in the subject, and the weight value in the region for each examination type. 5A is a view of the chest front, FIG. 5B is a view of the front of the thoracic spine, FIG. 5C is a view of the right side of the thoracic vertebra, and FIG. 5D is a view of the left side of the thoracic vertebra. The right side here means RL perspective. That is, the imaging apparatus is a fluoroscope in which the left side surface of the subject P is attached to the top plate 800 and X-rays are irradiated from the right side surface. On the other hand, the left side here means LR fluoroscopy, and is a fluoroscopy in which the right side surface of the subject P is attached to the top plate 800 and an X-ray is irradiated from the left side surface.

  FIGS. 5A to 5D are diagrams showing an X-ray image and the range of the first region of interest 320. FIG. The X-ray image here is processed so that the color becomes white as the dose increases.

  Reference numeral 324 denotes a region of interest in the subject P. The region of interest 324 is a region serving as a dose reference, and the position and size are different for each examination type. For example, if the examination type is chest front fluoroscopy, the region is the fifth intercostal region shown by the region of interest 324 in FIG. 5A, and if it is lumbar fluoroscopy, the region in the lumbar spine shown by the region of interest 324 in FIGS. is there. For the region of interest 324, there may be a case where a region serving as a reference for gradation is selected as a region, such as the fifth intercostal view of the chest front view. Alternatively, the region of interest 324 may be selected by, for example, an examination, such as lumbar fluoroscopy. In some cases, an area to be observed or diagnosed is selected.

  5A to 5D are diagrams showing the relationship between the weight value in each of the first region of interest 320 and the second region of interest 322 and the position in the first region of interest 320. FIG. . Here, in FIG. 6B, the upper graph shows the weight values in shades, the horizontal axis of the lower graph shows the position on the horizontal axis in the first region of interest 320, and the vertical axis shows the weight values. ing. Furthermore, the predetermined value th2 here is, for example, 1.0, and a region having a weight value of 1.0 or more is the second region of interest 322. In other words, the weight value in the second region of interest 322 is set to 1.0 or more. On the other hand, an area to which a weight value larger than 0.0 and less than 1.0 is an area excluding the second region of interest 322 in the first region of interest 320.

  The setting function 308 is connected to the input circuit 600 and, based on the examination type input from the input circuit 600, calls the coordinates 1 and 2 of the setting table shown in FIG. 4 from the storage circuit, and displays the first interest in the X-ray image. A region 320 and a second region of interest 322 are set. For example, the setting function 308 sets the first region of interest 320 and the second region of interest 322 in the X-ray image for each examination type, as shown in FIGS. 5A to 5D. Note that the examination type may be referred to as a fluoroscopy protocol.

  Here, when the ratio between the size of the region of interest 324 in the X-ray image and the size of the first region of interest 320 is small, body movement occurs in the subject P, and thus the region of interest 324 is generated from within the first region of interest 320. There is a high possibility that at least a part will protrude.

  The pixels in the region of interest 324 located outside the first region of interest 320 are not used for the calculation of the control value generated by the generation function 310, and there is a risk that the calculation accuracy of the control value will be reduced. Further, as described above, the region of interest 324 has a different size and position depending on the examination type. Therefore, in the present embodiment, the setting function 308 sets the first region of interest 320 wider than the region of interest 324 in the subject, and sets the size and position of the first region of interest 320 according to the examination type. In this case, the first region of interest 320 is set to a size based on body movement for each examination type of the region of interest 324. Here, the body movement means the movement of the body of the subject P during fluoroscopy. The body movement includes both body movement by voluntary muscles and body movement by involuntary muscles. In addition, the case where the body moves by an external force such as gravity, such as side perspective, is also included in the body movement.

  On the other hand, when the first region of interest 320 is enlarged, the contribution to the control value generated by the generation function 310 by the surrounding tissue of the region of interest 324 increases. Therefore, in the present embodiment, the setting function 308 sets a region to which a weight value equal to or greater than a predetermined value (th2) is set as the second region of interest 322. That is, the second region of interest 322 has a size based on the region of interest 324 and is set smaller than the first region of interest 320. As described above, the region of interest 324 has a different size and position for each examination type. Therefore, the setting function 308 sets the size and position of the second region of interest 322 based on the examination type.

  For example, the size and position of the first region of interest 320 are set based on the position of the region of interest 324 in the subject P for each examination type seen through in the past. This past image includes an image in which the position of the region of interest 324 fluctuates due to body movement. Thus, the first region of interest 320 can be set in a range where the region of interest 324 does not appear from within the first region of interest 320 even if general body movement occurs.

  Similarly, the size and position of the second region of interest 322 are set based on the position of the region of interest 324 in the subject P for each examination type seen through in the past. That is, the size and position of the second region of interest 322 are set based on the position where the region of interest 324 exists with a higher possibility. Thereby, at the time of fluoroscopy in which no body movement occurs, it is possible to further increase the ratio of pixels in the region of interest 324 contributing to the calculation of the control value. In other words, it is possible to further reduce the rate at which the surrounding tissue of the region of interest 324 contributes to the calculation of the control value.

  For example, the generation function 310 sets the weight value 2 in the second region of interest 322 to be larger than the weight value 1 in the first region of interest 320 excluding the second region of interest 322, as shown in the setting table of FIG. doing. Thus, the distribution of weight values used for weighting in the first region of interest is set in advance according to the examination type of the subject P.

  As can be seen from these, when the size of the first region of interest 320 is set to be larger than the region of interest 324 in the subject P, the generation function 310 generates when the body movement or displacement of the subject P occurs. The fluctuation of the control value is suppressed. On the other hand, in normal fluoroscopy in which no body movement or the like occurs, the weight value corresponding to the region of interest 324 is larger than the weight value of the other region. It is possible to increase.

  In the present embodiment, for example, as shown in FIGS. 5A and 5C, the ratio of the area of the second region of interest 322 to the area of the entire first region of interest 320 is varied depending on the examination type. For example, if the area of the second region of interest 322 is 80 (arbitrary unit) and the area of the entire first region of interest 320 is 100 (arbitrary unit), the second region of interest 322 with respect to the area of the entire first region of interest 320 will be described. The area ratio is 0.8. For example, if the area of the second region of interest 322 is 120 (arbitrary unit) and the area of the entire first region of interest 320 is 240 (arbitrary unit), the second interest with respect to the area of the entire first region of interest 320 will be described. The area ratio of the region 322 is 0.5. Here, the ratio 0.8 is defined to be larger than the ratio 0.5. Furthermore, here, the area of the entire first region of interest 320 is an area where the second region of interest 322 is not removed from the first region of interest 320. That is, the area of the entire first region of interest 320 is the same value whether or not the second region of interest 322 is included.

  More specifically, in frontal chest fluoroscopy in which the body movement of the subject P is less than thorax side fluoroscopy, the ratio of the area of the second region of interest 322 to the total area of the first region of interest 320 is larger than that of the thorax side fluoroscopy. Yes. In this case, the difference between the weight value 1 in the first region of interest 320 excluding the second region of interest 322 and the weight value 2 in the second region of interest 322 is also set smaller in the chest front perspective than in the thoracic spine side perspective. ing. Thus, the setting function 308 varies the area ratio between the second region of interest 322 and the entire first region of interest 320 according to the examination type. Further, according to the examination type, the generation function 310 makes the difference between the weight value 1 in the first region of interest 320 excluding the second region of interest 322 and the weight value 2 in the second region of interest 322 different. . Thereby, while suppressing the fluctuation | variation of a control value for every test | inspection type, it is possible to perform more accurately dose control for every test | inspection type.

  In the present embodiment, as shown in FIGS. 5C and 5D, the weight value closer to the chest in the first region of interest 320 is made smaller, and the weight value is made larger as the distance from the chest is increased. That is, in the thoracic vertebra right side fluoroscopy shown in FIG. 5C, the second region of interest 322 is set at a position shifted to the right from the center of the first region of interest 320.

  On the other hand, in the thoracic vertebra left side perspective shown in FIG. 5D, the second region of interest 322 is set at a position shifted to the left from the center of the first region of interest 320. Thus, for example, in side perspective, the distribution of weight values in the first region of interest 320 is asymmetrical. Thereby, even if a body movement occurs and the chest is included in the first region of interest, the pixel value in the chest is suppressed from contributing to the calculation of the control value.

  Further, in lateral perspective of the spinal system such as the thoracic vertebra, the first region of interest 320 is also set at a position shifted from the center of the image. For example, as shown in FIG. 5C, when the first region of interest 320 is at a position shifted to the right side from the center of the image, the chest is seen through on the left side of the first region of interest 320. For this reason, the second region of interest 322 is set at a position shifted to the right from the center of the first region of interest 320.

  In this way, by changing the position of the second region of interest 322 in the first region of interest 320 according to the examination type, it is possible to further suppress fluctuations in the control value caused by body movement, and for each examination type. It is possible to perform dose control more accurately.

Next, the calculation of the control value performed by the generation function 310 will be described in detail. The generation function 310 calculates a control value according to the following equation (1), for example.

  Here, the weight value is normalized by dividing the weight coefficient value by the sum of the weight coefficient values. That is, the total value of the weight values assigned to the pixel values in the first region of interest 320 and the second region of interest 322 is set to 1.0. By normalizing the weight value in this way, the control value can be handled in the same way as the pixel value of the X-ray image. Since the pixel value here is proportional to the X-ray dose, the control value is also proportional to the X-ray dose. The “weight value” is a value given to the weight assigned to each pixel value when performing an addition process for adding the pixel values. For example, in equation (1), (weighting factor value / total sum of weighting factor values) is the “weighting value”. However, for example, in the case where the weight value is not normalized and the weight coefficient value is not divided by (the sum of the weight coefficient values) in the equation (1), the weight coefficient value corresponds to the “weight value”. Will be. Thus, when calculating the control value, the weight value may be normalized or may not be normalized.

  Further, in the embodiment here, the effect of improving the S / N ratio is also achieved by using weighting for each pixel instead of thinning out pixels. For this reason, the X-ray dose transmitted through the region of interest 324 can be controlled more accurately.

  The above is the description of the configuration of the X-ray diagnostic apparatus 10 according to the first embodiment. A series of fluoroscopy processes in the X-ray diagnostic apparatus 10 according to the first embodiment will be described below.

  FIG. 6 is a flowchart illustrating a series of fluoroscopic flows according to the first embodiment. Step S <b> 100 is a step realized when the inspector inputs the inspection type from the input circuit 600. The signal indicating the examination type input in step S100 is input to the setting function 308, the generation function 310, the first gradation processing function 314, the F condition determination circuit 404, and the control circuit 406.

  Step S102 is a step corresponding to the control function, and the control function is realized by the control circuit 406 calling and executing a predetermined program corresponding to the control function from the second storage circuit 402. In step S <b> 102, the control function determines whether or not to end the inspection of the inspection type input from the input circuit 600. When a signal indicating another inspection type or an end signal is input (YES in step S102), the control function ends the inspection of the inspection type. On the other hand, when a signal indicating another inspection type or an end signal is not input from the input circuit 600 (NO in step S102), the inspection of the inspection type is continued.

  Step S104 is a step corresponding to the control function, and the control function is realized by the control circuit 406 calling and executing a predetermined program corresponding to the control function from the second storage circuit 402. In step S104, it is determined whether or not to continue irradiation with fluoroscopic X-rays. When an irradiation signal is input from the exposure button 500 to the control circuit 406 (YES in step S104), irradiation with fluoroscopic X-rays is continued. On the other hand, when the switch of the exposure button 500 is not pressed, the irradiation of fluoroscopic X-rays is stopped, and the control function performs the processing from step S102 (NO in step S104).

  Step S <b> 106 is realized by the F condition determination circuit 404 reading the F condition determination table 408 from the second storage circuit 402 and the dose index corresponding to the examination type input from the input circuit 600. In step S <b> 106, the F condition determination circuit 404 outputs an initially set mAs value and tube voltage to the control circuit 406 at the start of fluoroscopy. On the other hand, when the control value generated by the generation function 310 of the image processing apparatus 300 is input, the F condition determination circuit 404 controls the tube voltage and the mAs value based on the comparison between the dose index and the control value. Output to circuit 406.

  Step S108 is a step corresponding to the control function. This is a step in which the control function is realized when the control circuit 406 calls and executes a predetermined program corresponding to the control function from the second memory circuit 402. In step S <b> 108, the control circuit 406 outputs the fluoroscopy condition signal corresponding to the tube voltage and mAs value input from the F condition determination circuit 404 to the high voltage generator 102. Further, the control circuit 406 outputs an accumulation signal and an irradiation time signal indicating the irradiation time to the X-ray detector 202. Subsequently, the high voltage generator 102 supplies the tube voltage and a current corresponding to the mAs value to the X-ray tube 104. Further, in response to the accumulation signal from the control circuit 406, the X-ray detector 202 starts to accumulate charges. Subsequently, the X-ray detector 202 outputs an analog X-ray image signal based on accumulated charges to the AD conversion circuit 204 in accordance with the end of the irradiation time in accordance with the irradiation time signal input from the control circuit 406. Subsequently, the AD conversion circuit 204 converts it into a digital X-ray image signal and outputs it to the image correction circuit 206. Then, the image correction circuit 206 outputs the corrected X-ray image to the first storage circuit 302.

  Step S110 is a step in which the pixel value conversion function 306 is realized by the processing circuit 304 calling and executing a predetermined program corresponding to the pixel value conversion function 306 from the first storage circuit 302. In step S <b> 100, the pixel value conversion function 306 reads an X-ray image from the first storage circuit 302 and outputs, for example, an X-ray image subjected to logarithmic conversion processing to the setting function 308.

  Step S112 is a step in which the setting function 308 is realized by the processing circuit 304 calling and executing a predetermined program corresponding to the setting function 308 from the first storage circuit 302. In step SS112, the setting function 308 sets the first region of interest 320 and the second region of interest 322 in the X-ray image based on the input examination type.

  Step S114 is a step in which the generation function 310 is realized by the processing circuit 304 calling and executing a predetermined program corresponding to the generation fixed function from the first storage circuit 302. In step S114, the generation function 310 assigns a value greater than 0 to each pixel value in the first region of interest 320 according to the position in the first region of interest 320 based on the input examination type. Is added, and a control value is generated based on the value obtained by the addition process.

  Step S116 is a step in which the first gradation processing function 314 is realized by the processing circuit 304 calling and executing a predetermined program corresponding to the first gradation processing function 314 from the first storage circuit 302. In step S116, the first gradation processing function 314 performs gradation conversion into an image suitable for observation on the X-ray image input from the first storage circuit 302, and outputs it to the display 700.

  Step S118 is a step executed when the display 700 converts the image signal input from the first gradation processing function 314 into a luminance signal and displays it on the screen. Then, the control function of the control circuit 406 repeats the processing from step S104.

  As described above, according to the present embodiment, each pixel value in the first region of interest 320 is given a weight value in which a value greater than 0 is given according to the position in the first region of interest 320. An addition process is performed to add and the control value is generated based on the value obtained by the addition process. Thereby, it is possible to increase the weight given to the pixel in the region of interest 324 in the subject P, and the contribution of the pixel in the region of interest 324 to the generation of the control value used for the control of the X-ray irradiation apparatus 100 is achieved. Can be increased. For this reason, it is possible to further improve the accuracy of the control value during fluoroscopy.

  Further, the size of the first region of interest 320 is made larger than the size of the region of interest 324 in the subject based on fluctuations caused by body movement. As a result, even if body movement occurs in the subject P, at least a part of the region of interest 324 is suppressed from being located outside the first region of interest 320, so that fluctuations in the radiation dose to the subject P are suppressed. The

(Modification)
In the first embodiment described above, the weight value used for the generation function 310 is configured with binary values. However, in this modification, the weight value used for the generation function 310 is configured with three or more values. I have to. Hereinafter, a different part from 1st Embodiment mentioned above is demonstrated.

  Based on FIG. 7A to FIG. 7D, the weight value used for the generation function 310 according to the present modification will be described. FIG. 7A is a diagram showing ranges of the first region of interest 320, the second region of interest 322, and the third region of interest 326, and the second region of interest 322 is in the center. FIG. 7B is a diagram showing the ranges of the first region of interest 320, the second region of interest 322, and the third region of interest 326, with the second region of interest 322 in the right part. FIG. 7C is a diagram showing the ranges of the first region of interest 320, the second region of interest 322, and the third region of interest 326, with the second region of interest 322 on the left. FIG. 7D is a diagram illustrating weight values when the weight values in the first region of interest 320 continuously change.

  7A to 7C are diagrams showing ranges of the first region of interest 320, the second region of interest 322, and the third region of interest 326, and the lower diagram is a weight value in the first region of interest 320 and the first region of interest. 5 is a diagram showing a relationship with a position in an area 320. FIG. 7D is a diagram showing ranges of the first region of interest 320 and the second region of interest 322, and the lower diagram is a relationship between the weight value in the first region of interest 320 and the position in the first region of interest 320. FIG. In these lower drawings, the horizontal axis indicates the position on the horizontal axis in the first region of interest 320, and the vertical axis indicates the weight value. Here, the predetermined value th2 is, for example, 1.0, and a region having a weight value of 1.0 or more is the second region of interest 322.

  In the first embodiment, for example, as illustrated in FIGS. 5A to 5D, the setting function 308 sets the first region of interest 320 and the second region of interest 322. In this case, when the body movement of the subject P occurs and the region of interest 324 protrudes from the second region of interest 322, the control value (for example, equation (1)) may fluctuate discontinuously.

  Therefore, in this modified example, as shown in FIGS. 7A to 7C, the setting function 308 sets the third region of interest 326 in the first region of interest 320 and the second region of interest in the third region of interest 326. 322 is set. In this case, the generation function 310 assigns a first-stage weight value in the second region of interest 322, assigns a second-stage weight value in the third region of interest 326 excluding the second region of interest 322, and A third-stage weight value is assigned to the first region of interest 320 excluding the three regions of interest 326. In this way, by changing the number of stages, when the region of interest 324 of the subject P moves in the first region of interest 320 due to body movement, the fluctuation of the control value (for example, the expression (1)) can be made gentler. . Thereby, the fluctuation of the X-ray dose can be made more gentle.

  As shown in FIG. 7D, when the weight value is continuously changed, the control value varies when the region of interest 324 of the subject P moves in the first region of interest 320 due to body movement. Can be made continuous, and the variation of the X-ray dose can also be made continuous. The weight values shown in FIG. 7D are generated in accordance with, for example, a normal distribution arithmetic expression centered at x = XA (average value). That is, the generation function 310 of the image processing apparatus 300 generates a weight value according to a normal distribution arithmetic expression. In this case, according to the coordinates of the second region of interest 322, coordinates having a weight value of 1.0 are set in advance.

  As described above, in this modification, the first region of interest 320 is made wider than the region of interest 324 in the subject, and the variation of the weight value in the first region of interest 320 is made gentler. Thereby, when the region of interest 324 of the subject P moves in the first region of interest 320, the variation in the X-ray dose irradiated to the subject P can be made gentler. Thereby, the fluctuation | variation of the luminance value corresponding to the region of interest in the subject can be made smoother.

(Second Embodiment)
In the first embodiment described above, the examiner inputs the examination type to the X-ray diagnostic apparatus 10. However, in the second embodiment, the fluoroscopic sequence setting function 328 follows the fluoroscopic sequence, and the examination type is set to the X-ray. The data is input to the diagnostic device 10. Hereinafter, a different part from 1st Embodiment mentioned above is demonstrated.

  FIG. 8 is a block diagram for explaining the configuration of the X-ray diagnostic apparatus 10 according to the second embodiment. As shown in FIG. 8, the image processing apparatus 300 further includes a fluoroscopic sequence setting function 328, which is different from the first embodiment. When the processing circuit 304 calls and executes a predetermined program corresponding to the fluoroscopic sequence setting function 328 from the second storage circuit 402, the fluoroscopic sequence setting function 328 is realized. That is, the fluoroscopic sequence setting function 328 is a function for calculating a control value used for controlling the X-ray irradiation apparatus 100, similarly to the pixel value conversion function 306, the setting function 308, and the generation function 310.

  The fluoroscopic sequence setting function 328 will be described based on FIG. 9 with reference to FIG. FIG. 9 is a diagram illustrating a part of a series of fluoroscopic operations in lumbar myelography. (A) is a figure which shows the X-ray image seen through the fluoroscopic apparatus 200 in time series. Moreover, (b) is a figure which shows the 1st region of interest 320 and the 2nd region of interest 322 which the setting function 308 sets to a time series corresponding to an X-ray image. Here, the myelography is a clinical test for diagnosing the shape of the spinal cavity and the like. In myelography, a contrast medium is injected into the spinal cavity, and the flow of the contrast medium is observed by fluoroscopy. As described above, in X-ray fluoroscopy, examination types to be seen in time series may be determined in advance. In this case, if the examiner inputs examination types from the input circuit 600 in time series, there is a possibility that the flow of X-ray fluoroscopy is interrupted.

  For this reason, in the present embodiment, as shown in FIG. 8, the first storage circuit 302 stores the order of examination types to be seen in time series for each fluoroscopic examination. Here, the order of examination types that are seen through in time series is referred to as a fluoroscopic sequence. For example, when the fluoroscopy is lumbar myelography, the front of the thoracic vertebra, the left side of the thoracic vertebra, the right side of the thoracic vertebra, etc. are stored in chronological order as the fluoroscopic sequence. Further, for example, when the fluoroscopic examination is gastroscopic fluoroscopy, the abdominal front, the abdominal right 10-degree side, the abdominal right 30-degree side, and the like are stored in chronological order as the fluoroscopic sequence. The first storage circuit 302 stores a fluoroscopic sequence for each fluoroscopic examination such as lumbar myelography, cervical spinal myelography, gastrograph, cholangiography, and urinary system contrast.

  The fluoroscopic sequence setting function 328 outputs examination types in time series according to the fluoroscopic sequence. Specifically, the fluoroscopic sequence setting function 328 includes a first storage circuit 302, a setting function 308, a generation function 310, a first gradation processing function 314, an F condition determination circuit 404, a control circuit 406, When connected to the exposure button 500 and the input circuit 600 and an instruction to start a fluoroscopic examination is input from the input circuit 600, a fluoroscopic sequence corresponding to the fluoroscopic examination is read from the first storage circuit 302. For example, the fluoroscopy sequence setting function 328 sets the examination type according to the fluoroscopy sequence according to the fluoroscopy time set in advance, the setting function 308, the generation function 310, the first gradation processing function 314, and the F condition determination circuit 404. And output to the control circuit 406. Further, the fluoroscopic sequence setting function 328 of the present embodiment outputs an end signal after outputting a series of examination types. For example, the fluoroscopic sequence setting function 328 sets the examination type according to the fluoroscopic sequence based on the irradiation signal input from the exposure button 500, the generation function 310, the first gradation processing function 314, the F condition. The data may be output to the determination circuit 404 and the control circuit 406.

  An example of fluoroscopy using this fluoroscopy sequence setting function 328 will be described with reference to FIG. FIG. 10 is a flowchart showing a series of flows in fluoroscopy using the fluoroscopy sequence setting function 328. The same processes as those in FIG. 6 in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted if unnecessary.

  Step S <b> 120 is a step realized when the examiner inputs the type of fluoroscopic inspection from the input circuit 600. The type of fluoroscopic examination input in step S120 is input to the fluoroscopic sequence setting function 328.

  Step S122 is a step in which the fluoroscopic sequence setting function 328 is realized by the processing circuit 304 calling and executing a predetermined program corresponding to the fluoroscopic sequence setting function 328 from the first storage circuit 302. In step S122, the fluoroscopic sequence setting function 328 reads the fluoroscopic sequence of the fluoroscopic examination input from the input circuit 600 from the first storage circuit 302, and sets the examination type indicated in the fluoroscopic sequence according to the progress of fluoroscopy. , Output to the control circuit 406, the setting function 308, the generation function 310, and the first gradation processing function 314. Further, the fluoroscopic sequence setting function 328 here outputs an end signal when a series of processing ends.

  Step S100 is a step of inputting the examination type as in FIG. 6 in the first embodiment. Step S100 here is a step in which the fluoroscopic sequence setting function 328 is realized by the processing circuit 304 calling and executing a predetermined program corresponding to the fluoroscopic sequence setting function 328 from the first storage circuit 302. In step S100, the fluoroscopic sequence setting function 328 outputs the examination type indicated in the fluoroscopic sequence to the setting function 308, the generation function 310, the first gradation processing function 314, the F condition determination circuit 404, and the control circuit 406. In this case, one fluoroscopic type arranged in time series is output in order.

  Step S124 is a step corresponding to the control function, and the control function is realized when the control circuit 406 calls and executes a predetermined program corresponding to the control function from the second memory circuit 402. In step S128, it is determined whether or not to end a series of inspections based on the type of fluoroscopic inspection. When the examination type is input from the fluoroscopic sequence setting function 328 (NO in step S124), a series of examinations are continued and the processing from step S100 is performed. On the other hand, when the end signal is input from the fluoroscopic sequence setting function 328 (NO in step S124), the series of inspections is ended.

  As described above, in the present embodiment, when the type of fluoroscopic examination is input, the fluoroscopic sequence setting function 328 follows the fluoroscopic sequence corresponding to the fluoroscopic examination, and the first region of interest 320 and the second region of interest 322. The position is automatically changed for each inspection type. This eliminates the need for the inspector to input the inspection type and improves operability.

  In addition, the X-ray irradiation apparatus 100 in 1st Embodiment is an example of the X-ray irradiation part in a claim, and the collection apparatus 200 is an example of the acquisition part in a claim. The setting function 308 in the first embodiment is an example of a setting unit in the claims. Moreover, the setting function 308 in the modification of 1st Embodiment is another example of the setting part in a claim. The generation function 310 in the first embodiment is an example of a generation unit in the claims. The generation function 310 in the modification of the first embodiment is another example of the generation unit in the claims.

  The control device 400 in the first embodiment is an example of a control unit in the claims, and the first gradation processing function 314 is an example of a first gradation processing unit in the claims. The fluoroscopic sequence setting function 328 in the second embodiment is an example of a sequence setting unit in the claims. The display 700 in the first embodiment is an example of an image display unit in the claims.

  The term “processor” used in the above description is, for example, a CPU (central processing unit), a GPU (Graphics Processing Unit), or an application specific integrated circuit (ASIC), a programmable logic device (for example, Simple Programmable Logic Device (SPLD), Composite Programmable Logic Device (CPLD), and Field Programmable Gate Array (FPGA) It means the road. The processor implements a function by reading and executing a program stored in the storage circuit. Instead of storing the program in the storage circuit, the program may be directly incorporated in the processor circuit. In this case, the processor realizes the function by reading and executing the program incorporated in the circuit. Note that each processor of the present embodiment is not limited to being configured as a single circuit for each processor, but may be configured as a single processor by combining a plurality of independent circuits to realize the function. Good. Further, a plurality of components shown in FIGS. 1, 8, and 11 may be integrated into one processor to realize the function.

  Although several embodiments have been described above, these embodiments are presented as examples only and are not intended to limit the scope of the invention. The novel apparatus, methods and systems described herein can be implemented in various other forms. In addition, various omissions, substitutions, and changes can be made to the forms of the devices, methods, and systems described in the present specification without departing from the spirit of the invention. The appended claims and their equivalents are intended to include such forms and modifications as fall within the scope and spirit of the invention.

10: X-ray diagnostic apparatus, 100: X-ray irradiation apparatus, 200: Collection apparatus, 300: Image processing apparatus, 308: Setting function, 310: Generation function, 314: First gradation processing function, 320: First region of interest 322: second region of interest, 324: region of interest in subject, 328: fluoroscopic sequence setting function, 400: control device, 700: display, P: subject

Claims (14)

An X-ray irradiation unit that irradiates the subject with X-rays;
An acquisition unit that repeatedly acquires an X-ray image of the X-ray transmitted through the subject in response to irradiation of the X-ray irradiation unit;
A setting unit that sets, in the X-ray image, a first region of interest that is a region used for control of the X-ray irradiation unit;
According to the X-ray image acquired by the acquisition unit, each pixel value in the first region of interest of the X-ray image is assigned a weight value greater than 0 according to the position in the first region of interest. A generation unit that performs addition processing to add the assigned weight and generates a control value based on the value obtained by the addition processing;
A control unit that controls the X-rays emitted by the X-ray irradiation unit so that the control value approaches a predetermined value;
An X-ray diagnostic apparatus comprising: The setting unit sets the first region of interest so as to include the region of interest in the subject,
The X-ray diagnosis apparatus according to claim 1, wherein the weight value of the region of interest in the subject is larger than the weight value of another region in the first region of interest.   The size of the first region of interest is determined based on body movement for each examination type, and the distribution of the weight values in the first region of interest is set in advance according to the examination type of the subject. The X-ray diagnostic apparatus according to claim 1 or 2.   The X-ray diagnostic apparatus according to any one of claims 1 to 3, wherein a distribution of the weight values in the first region of interest is asymmetrical. The first region of interest is divided into a second region of interest in which the addition process is performed with a weight value greater than or equal to a predetermined value and other regions,
The X-ray diagnostic apparatus according to claim 1, wherein the setting unit sets the second region of interest according to an examination type of the subject.   The X-ray diagnostic apparatus according to claim 5, wherein a ratio of the area of the second region of interest to the area of the entire first region of interest varies depending on the examination type.   The X-ray diagnostic apparatus according to claim 6, wherein when the fluoroscopic part is the same, the ratio in frontal fluoroscopy is greater than the ratio in side fluoroscopy. When the first region of interest is shifted to the right from the center of the X-ray image, the second region of interest is set to a position shifted to the right from the center of the first region of interest,
6. The second region of interest is set at a position shifted to the left side from the center of the first region of interest when the first region of interest is shifted to the left side from the center of the X-ray image. The X-ray diagnostic apparatus according to any one of 7.   The X-ray diagnostic apparatus according to claim 5, wherein the second region of interest is defined by coordinates in the X-ray image, and the weight value is set based on the coordinates.   The X-ray diagnosis apparatus according to any one of claims 1 to 9, wherein the weight value in the first region of interest continuously changes according to a position in the first region of interest. It further includes a sequence setting unit that outputs the examination types in time series,
10. The setting unit according to claim 5, wherein the setting unit sets the first region of interest and the second region of interest at a predetermined position according to the examination type input from the sequence setting unit. X-ray diagnostic equipment.   The control unit controls a tube voltage supplied to the X-ray irradiation unit and a current corresponding to a mAs value so that the control value approaches a dose index determined by an examination type. The X-ray diagnostic apparatus according to Item. An irradiation step of irradiating the subject with X-rays at a predetermined time interval;
An acquisition step of repeatedly acquiring an X-ray image of the X-ray transmitted through the subject in response to the X irradiation;
A setting step of setting, in the X-ray image, a first region of interest that is a region used for controlling the X-ray;
In accordance with the X-ray image acquired in the acquisition step, each pixel value in the first region of interest of the X-ray image has a weight value greater than 0 depending on the position in the first region of interest. A generation step of performing addition processing to add the assigned weight and generating a control value based on the value obtained by the addition processing;
A control step of controlling the X-ray so that the control value approaches a predetermined value;
A method for controlling an X-ray diagnostic apparatus. A setting unit for setting a first region of interest, which is a region used for controlling the X-rays, in an X-ray image based on the X-ray dose transmitted through the subject;
Performing an addition process for adding each pixel value in the first region of interest of the X-ray image with a weight to which a weight value greater than 0 is given according to the position in the first region of interest; A generating unit that generates a control value used for X-ray dose control based on the value obtained by the addition process;
An image processing apparatus comprising: