JP7015113B2 - X-ray diagnostic device, control method of X-ray diagnostic device, and image processing device - Google Patents

Description

The present embodiment relates to an X-ray diagnostic apparatus, a control method of 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. As a result, 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 the subject moves, 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 transmitted through the region of interest in the subject fluctuates. May be done. As a result, the luminance value in the region of interest in the subject also fluctuates, which may make it unsuitable for observation or diagnosis.

Japanese Unexamined Patent Publication No. 9-106016

An object of the present embodiment is to provide an X-ray diagnostic apparatus capable of suppressing fluctuations in the X-ray dose transmitted through a region of interest in a subject, a control method for the X-ray diagnostic apparatus, and an image processing apparatus.

The X-ray diagnostic apparatus according to the present embodiment has an X-ray irradiation unit that irradiates an X-ray toward a subject, and an X-ray X-ray that has passed through the subject in response to irradiation by the X-ray irradiation unit. For acquisition of the X-ray image by the acquisition unit, a setting unit for repeatedly acquiring an image, a setting unit for setting a first area of interest, which is a region used for controlling the X-ray irradiation unit, in the X-ray image, and an acquisition unit. Accordingly, an addition process is performed in which each pixel value of the X-ray image in the first interest region is added with a weight given by a weight value larger than 0 according to the position in the first interest region. A generation unit that generates a control value based on the value obtained in 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. , Equipped with.

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 processed by the logarithmic transformation function. The figure which shows the time change of the control value generated by the generation function of an image processing apparatus. The figure which shows an example of the area and weight value setting table set for each inspection type. (A) is a figure showing an X-ray image of the front of the chest and the range of the first region of interest. (B) is a diagram showing the relationship between the weight value in each of the first and second regions of interest on the front of the chest and the position in the first region of interest. (A) is a diagram showing an X-ray image of the front of the thoracic spine and the range of the first region of interest. (B) is a diagram showing the relationship between the weight value in each of the first and second regions of interest on the anterior surface of the thoracic spine and the position in the first region of interest. (A) is an X-ray image of the right side surface of the thoracic spine and a diagram showing the range of the first region of interest. (B) is a diagram showing the relationship between the weight value in each of the first and second regions of interest on the right side of the thoracic spine and the position in the first region of interest. (A) is an X-ray image of the left side surface of the thoracic spine and a diagram showing the range of the first region of interest. (B) is a diagram showing the relationship between the weight value in each of the first and second regions of interest on the left side of the thoracic spine and the position in the first region of interest. The figure which shows the flowchart which showed the series flow of fluoroscopy which concerns on 1st Embodiment. It is a figure which shows the range of the 1st area of interest, the 2nd area of interest, and the 3rd area of interest, and is the figure which the 2nd area of interest is in the central part. It is a figure which shows the range of the 1st area of interest, the 2nd area of interest, and the 3rd area of interest, and is the figure which the 2nd area of interest is in the right part. It is a figure which shows the range of the 1st area of interest, the 2nd area of interest, and the 3rd area of interest, and is the figure which the 2nd area of interest is in the left part. The figure which shows the weight value when the weight value in the 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 showing an X-ray image seen through in time series in myelography of the lumbar spine. (B) is a diagram showing a first region of interest and a second region of interest set by the setting function in time series corresponding to an X-ray image. The figure which shows the flowchart which showed the series flow in fluoroscopy using the fluoroscopy sequence setting function.

Hereinafter, the X-ray diagnostic apparatus 10 according to the embodiment will be described with reference to the drawings. In the following description, components having substantially the same function and configuration are designated by the same reference numerals, and duplicate explanations will be given 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 the configuration of the X-ray diagnostic apparatus 10 according to the first embodiment. As shown in FIG. 1, the X-ray diagnostic apparatus 10 is an apparatus capable of seeing through X-rays of a subject P, and is an X-ray irradiation apparatus 100, a collection apparatus 200, an image processing apparatus 300, and a control apparatus 400. The X-ray button 500, the input circuit 600, the display 700, and the top plate 800 are provided.

The X-ray irradiation device 100 repeatedly irradiates the subject P with X-rays at predetermined time intervals. The X-ray irradiation device 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 the tube voltage and the 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 has, for example, a transformer and a rectifier. The transformer is connected to an AC power supply and boosts the AC voltage supplied from the AC power supply according to the set tube voltage. Then, the transformer 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. Further, 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 see-through condition signal indicating the tube voltage, the tube current, the pulse width, and the pulse rate is generated from the control device 400 at a high voltage. It is input to the device 102. The high voltage generator 102 supplies the tube voltage based on the see-through condition signal and the current corresponding to the tube current to the X-ray tube 104 at time intervals corresponding to the inverse of the pulse rate during the pulse width based on the see-through 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. The time interval in the present 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 as a cathode and a target metal as an anode in a vacuum enclosure. 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 coiled from a metal such as tungsten and generates thermions when a current corresponding to the tube current is supplied from the high voltage generator 102. That is, the number of thermions 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. Thermions accelerated by this electric field collide with the target metal of the anode, and X-rays are generated from the target metal. As the tube voltage increases, the wavelength peak of the X-ray shifts to the short wavelength side, and the energy of the X-ray also increases.

Here, the intensity of X-rays is the energy of X-rays that pass through a unit area in a unit time. Also. The X-ray dose is the product of the intensity of X-rays and the irradiation time. As can be seen from these facts, the X-dose is proportional to the mAs value and increases as the tube voltage increases.

The X-ray movable diaphragm 106 has a feather-shaped diaphragm made of lead or the like. The X-ray movable diaphragm 106 is arranged at the exit port 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. This limits the range in which the subject P is irradiated with X-rays. Here, the examiner manually moves the aperture before and during fluoroscopy. The movement of the aperture may be driven by a motor according to a control signal from the control device 400.

The collection device 200 repeatedly collects X-ray images of X-rays that have passed through the subject P in response to the irradiation of the X-ray irradiation device 100. The collecting device 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 on a pixel-by-pixel basis, and outputs an image signal proportional to the detected X-ray dose on a pixel-by-pixel basis. Here, the X-ray image is a two-dimensional X-ray intensity distribution.

For example, the X-ray detector 202 is configured by a plane detector (FPD: Flat Panel Detector) for detecting X-rays applied to the detection surface. The FPD has an image sensor, and the image sensor includes a CMOS image sensor (Complementary Metal Oxide Semiconductor Image Sensor), a CCD (Charge Coupled Device), a thin film transistor (TFT: thin film transistor), and the like.

More specifically, the X-ray detector 202 is connected to the control device 400 and is controlled according to, for example, a storage signal and an irradiation time signal input from the control device 400. Further, the drive 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 according to a stored signal stores an electric charge according to an X-ray dose while X-rays are emitted from an X-ray tube 104. Then, according to the irradiation time signal, the photodiode corresponding to each of these pixels converts the stored charge into a voltage and outputs the voltage signal amplified by the amplifier as an analog image signal according to the end of the irradiation time. ..

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 device 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 is a gain correction process for correcting the sensitivity non-uniformity of each pixel in the X-ray detector 202 for a digital image signal, and a defect pixel correction for correcting pixel omission. A correction process such as processing is performed to generate an X-ray image after the correction process. The image correction circuit 206 outputs the corrected X-ray image to the first storage circuit 302 of the image processing device 300. In the present embodiment, an image based on the 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 by the AD conversion circuit 204. Further, the X-ray image also includes an image obtained by subjecting the X-ray digital image to correction processing such as gain correction processing and defect pixel correction processing.

The image processing device 300 processes an X-ray image based on the X-ray image collected by the collecting device 200, and generates a control value for controlling the dose of X-rays irradiated by the X-ray irradiating device 100. Further, 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 a program form 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, weight values, and the like for realizing each processing function in the processing circuit 304, which will be 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 realizes each processing function corresponding to each program by reading a program from the first storage circuit 302 and executing the program. In other words, the processing circuit 304 in the state where each program is read out has each processing function. Although it has been described in FIG. 1 that each processing function is realized by a single processing circuit 304, a 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 collection device 200, the first storage circuit 302, the control device 400, the display 700, and the like, and is an X-ray image read from the first storage circuit 302. Is processed, and the processing result is output 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 the control value used for controlling the X-ray irradiation device 100. On the other hand, the image processing function 312 and the first gradation processing function 314 are functions used for image processing an X-ray image and generating 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 values 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 showing a histogram of an X-ray image processed by logarithmic transformation, which is an example of the pixel value conversion function 306. The left figure is a diagram showing the frontal image of the thoracic spine and the first region of interest 320 described later, the middle figure is a histogram of the pixel values in the first region of interest before logarithmic conversion, and the right figure is a logarithmic conversion. It is a histogram of the pixel value in the first area of interest 320 after that. In the histogram, the horizontal axis shows the pixel value, and the vertical axis shows the appearance frequency for each pixel value.

The pixel value conversion by the pixel value conversion function 306 is performed so as to stretch the portion whose brightness is to be matched and compress the other portion. For example, when it is desired to match the brightness to the mediastinum in the chest examination shown in the left figure of FIG. 2, the pixel value conversion expands the mediastinum, that is, the region where the pixel value is low, and compresses the lung field, that is, the region where the pixel value is high, for example, logarithm. The conversion is done. As a result, the region closer to the lower pixel value (mediastinum) becomes the brightness suitable for observation. The region with a high pixel value (lung field) becomes bright and difficult to observe, but since it is a region with a large dose and little noise, it can be observed by correcting it with existing technology such as dynamic range compression processing. In this way, if logarithmic conversion is used for the pixel value conversion function 306 and existing correction technology such as dynamic range compression processing is used in combination, a wide range can be observed, so there is no part where you want to positively adjust the brightness, which is general. Logarithmic conversion is suitable for ABC applications.

Returning to FIG. 1 again, the setting function 308 sets the first region of interest, which is a region used for controlling the X-ray irradiation device 100, in the X-ray image based on the X-ray image. The X-ray image here is an image in which the pixel value is converted by the pixel value conversion function 306. Further, an image obtained by subjecting an image based on the dose of X-rays transmitted through the subject P to various image processing 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.

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

The generation function 310 performs an addition process of adding a weight to each pixel value in the first area of interest of the X-ray image with a weight value larger than 0 according to the position in the first area of interest. , A control value for controlling the X-ray irradiation apparatus 100 is generated based on the value obtained in 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 corrected X-ray image.
The first gradation processing function 314 shifts any gradation 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. Perform the first gradation processing to be converted. Which image gradation processing is performed by the first gradation processing function 314 can be determined by, for example, a selection instruction from the input circuit 600. The pixel value conversion characteristic by the first gradation processing function 314 may be changed depending on the portion where the brightness is desired to be matched. 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. Is connected to the input circuit 600 and the display 700, and controls the entire X-ray diagnostic apparatus 1. Specifically, the control device 400 includes a second storage circuit 402, an F condition determination circuit 404, and a control circuit 406.

The second storage circuit 402, like the first storage circuit 302 described above, has a configuration including 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 a program form that can be executed by a computer. Further, the second storage circuit 402 stores a dose index, which is an index of the X dose transmitted through the subject P, for each test type, and stores the F condition determination table 408 shown in FIG. In this F condition determination table 408, the horizontal axis shows the tube voltage (F_kV), and the vertical axis shows the mAs value (F_mAs) which is the product of the tube current and the pulse width. FIG. 1 shows a combination of a tube voltage (F_kV) in which the X-ray dose becomes larger according to the direction indicated by the arrow 410 and a mAs value (F_mAs).

The F condition determination circuit 404 controls the tube voltage and the mAs value, which are the fluoroscopic conditions in the next fluoroscopy, based on the dose index according to the inspection 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 realizes each function corresponding to each program by reading a 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 device 100 and the F condition determination circuit 404, and the control value generated by the generation function 310 is used as the dose index determined by the inspection type. The current and pulse width corresponding to the tube voltage supplied to the X-ray tube 104 of the X-ray irradiation device 100 and the mAs value are controlled so as to bring them closer to each other. That is, the control circuit 406 outputs the fluoroscopic condition signal based on the tube voltage input from the F condition determination circuit 404 and the mAs value to the high voltage generator 102. Details of the series of fluoroscopic processing 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 inspection type to the display 700 as a video signal for each inspection type based on the inspection type information read from the first storage circuit 302.

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

The input circuit 600 is realized by a trackball, a switch button, a mouse, a keyboard, etc. for setting an inspection type, a fluoroscopy 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 electric signal, and outputs the input operation to the control circuit 406. In the present embodiment, when a signal indicating an inspection type is input from the input circuit 600 to the control circuit 406, the control circuit 406 starts the inspection of the inspection type. On the other hand, when a signal indicating another inspection type or an end signal indicating termination is input from the input circuit 600, the control circuit 406 ends the inspection of that 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, converts an X-ray image or the like processed by the processing circuit 304 into a luminance signal, and displays it on the screen. Further, the display 700 is connected to the control circuit 406, and as described above, the video signal of the button indicating each inspection type input from the control circuit 406 is converted into a luminance signal and displayed on the screen. For example, when a button indicating an inspection type displayed on the display 700 is instructed to the inspector, a signal indicating the inspection 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 inspection type is completed, the 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 high X-ray transmittance. The subject P in a lying state is placed on the top plate 800.

Next, the fluoroscopic condition control of the control circuit 406 used for ABC will be described with reference to FIG. 1 and FIG. FIG. 3 is a diagram showing a time change of the control value 412 generated by the generation function 310 of the image processing apparatus 300. The horizontal axis shows the elapsed time, and the vertical axis shows the control value. Similar to FIG. 3, 412 in FIG. 3 shows a control value when the examination type is frontal chest fluoroscopy, and 414 shows a dose index as a reference for frontal chest 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 fluoroscopic condition in the current fluoroscopy according to the F condition determination table 408, and causes the control circuit 406. Output. As a result, the control circuit 406 outputs the tube voltage of the fluoroscopy condition in the current fluoroscopy, the tube voltage for the next fluoroscopy in which the mAs value is reduced, and mAs as the fluoroscopy condition signal to the high voltage generator 102. That is, in the next fluoroscopy, the X-ray dose that penetrates the subject is reduced.

On the other hand, when the control value 412 is smaller than the dose index 414, the F condition determination circuit 404 is used for the next fluoroscopy in which both the mAs value and the tube voltage of the fluoroscopic condition in the current fluoroscopy are increased according to the F condition determination table 408. 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 penetrates the subject increases. The fluoroscopy condition does not necessarily have to be the next fluoroscopy, and may be changed after irradiation with X-rays of several to several tens of pulses.

As can be seen from these, the control circuit 406 controls the high voltage generator 102 so that the control value 412 approaches the dose index 414 determined by the inspection type based on the input from the F condition determination circuit 404. As described above, 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 with reference to FIGS. 1 and 5A to 5D. FIG. 4 is a diagram showing an example of an area and weight value setting table set for each inspection type. In FIG. 4, the front surface of the chest, the front surface of the lumbar spine, the right side surface of the lumbar spine, and the left side surface of the lumbar spine are shown as examples of the inspection types.

Coordinates 1 are coordinates indicating the first region of interest of the quadrangle, and indicate the coordinates of the origin in this quadrangle and the coordinates of the diagonal points connected to the origin by a diagonal line. The weight value 1 indicates a weight given to a region in the first region of interest excluding the second region of interest. Here, the weight value corresponds to the value of the weighting factor. This weight value may be normalized as shown in the equation (1) described later. Coordinates 2 are coordinates indicating the second region of interest of the quadrangle, and indicate the coordinates of the origin of the quadrangle and the coordinates 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. Two second regions of interest are set in front of the chest. As described above, 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 inspection type is a protocol including, for example, a fluoroscopy site and a perspective direction in an inspection of the front surface of the lumbar spine, the side surface of the lumbar spine, the front surface of the chest, the front surface of the head, the side surface of the chest, the front surface of the abdomen, the front surface of the hand, the front surface of the foot, and the like. The fluoroscopic site is a part of the body in the subject P, for example, the part is the lumbar spine, the chest, the head, the abdomen, the hands, the feet, and the like. Furthermore, the fluoroscopic direction is the direction of the subject P facing the traveling direction of the X-ray, for example, the front surface, the back surface, the right side surface, the left side surface, and the like. As described above, in the setting table stored in the first storage circuit 302, the information of the coordinate 1, the weight value 1, the coordinate 2, and the weight value 2 is registered for each inspection 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, or a pentagon may be used.

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

(A) in FIGS. 5A to 5D is a diagram showing an X-ray image and a range of the first region of interest 320. In the X-ray image here, the color is processed so as to become whiter as the dose increases.

324 indicates a region of interest within the subject P. The region of interest 324 is a region that serves as a dose reference, and its position and size differ depending on the examination type. For example, if the examination type is anterior chest fluoroscopy, it is the region of the fifth intercostal region shown in the region of interest 324 of FIG. be. In the region of interest 324, a region that serves as a reference for gradation may be selected as a region, such as the fifth intercostal space of anterior chest fluoroscopy, or in the region of interest 324, such as lumbar fluoroscopy, for example, by examination. In some cases, the area to be observed or diagnosed may be selected.

Further, (b) in FIGS. 5A to 5D is a diagram showing the relationship between the weight value in each of the first interest region 320 and the second interest region 322 and the position in the first interest region 320. .. Here, in the figure (b), the upper figure shows the weight value 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 value. ing. Furthermore, the predetermined value th2 here is, for example, 1.0, and the 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, the region to which the weight value larger than 0.0 and less than 1.0 is given is the region in the first interest region 320 excluding the second interest region 322.

The setting function 308 is connected to the input circuit 600, and based on the inspection type input from the input circuit 600, the coordinates 1 and 2 of the setting table shown in FIG. 4 are called from the storage circuit, and the first interest in the X-ray image. The region 320 and the 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 inspection type, as shown in FIGS. 5A to 5D. The inspection type may be referred to as a fluoroscopy protocol.

Here, if the ratio between the size of the region of interest 324 and the size of the first region of interest 320 in the X-ray image is small, body movement occurs in the subject P, so that the region of interest 324 is located within the first region of interest 320. There is a high possibility that at least a part of it will stick out.

The pixels in the region of interest 324 located outside the first region of interest 320 are not used in the calculation of the control value generated by the generation function 310, and the calculation accuracy of this control value may decrease. Further, as described above, the size and position of the region of interest 324 differ depending on the inspection type. Therefore, in the present embodiment, the setting function 308 sets the first area of interest 320 wider than the area of interest 324 in the subject, and sets the size and position of the first area of interest 320 according to the test type. In this case, the first region of interest 320 is set to a size based on the body movement of the region of interest 324 for each examination type. Here, the body movement means the movement of the body of the subject P during fluoroscopy. Body movements include both body movements by voluntary muscles and body movements by involuntary muscles. In addition, the case where the body moves due to an external force such as gravity, such as lateral fluoroscopy, is also included in the body movement.

On the other hand, if the first region of interest 320 is increased, 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 of a predetermined value (th2) or more is given as a second region of interest 322. That is, the second region of interest 322 is 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 inspection type. Therefore, the setting function 308 sets the size and position of the second region of interest 322 based on the inspection 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 that has been seen through in the past. This past image includes an image in which the position of the region of interest 324 is changed due to body movement. Thereby, the first interest region 320 can be set in a range in which the interest region 324 does not appear from within the first interest region 320 even if a 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 that has been seen through in the past. That is, the size and position of the second region of interest 322 is set based on the position where the region of interest 324 is more likely to exist. This makes it possible to further increase the proportion of pixels in the region of interest 324 that contribute to the calculation of the control value during fluoroscopy without body movement. In other words, the proportion of the surrounding tissue of the region of interest 324 that contributes to the calculation of the control value can be further reduced.

For example, as shown in the setting table of FIG. 4, the generation function 310 sets the weight value 2 in the second interest region 322 to be larger than the weight value 1 in the first interest region 320 excluding the second interest region 322. is doing. As described above, the distribution of the weight values used for the weighting in the first region of interest is preset according to the test type of the subject P.

As can be seen from these, by setting the size of the first region of interest 320 to be larger than the region of interest 324 in the subject P, the generation function 310 is generated when the body movement or misalignment of the subject P occurs. Fluctuations in the control value to be performed are suppressed. On the other hand, in normal fluoroscopy in which no body movement occurs, the weight value corresponding to the region of interest 324 is larger than the weight value of the other region, so that the contribution to the control value of the pixels in the region of interest 324 is contributed. It is possible to increase.

Further, in the present embodiment, as shown in FIGS. 5A and 5C, for example, the ratio of the area of the second interest region 322 to the area of the entire first interest region 320 is different depending on the inspection 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. The ratio of the area of is 0.8. Further, for example, if the area of the second area of interest 322 is 120 (arbitrary unit) and the area of the entire first area of interest 320 is 240 (arbitrary unit), the second interest in the area of the entire first area of interest 320 is 240 (arbitrary unit). The area ratio of the area 322 is 0.5. Here, the ratio 0.8 is defined to be larger than the ratio 0.5. Further, here, the area of the entire first interest region 320 is an area that does not exclude the second interest region 322 from the first interest region 320. That is, the area of the entire first interest region 320 is the same value regardless of whether the second interest region 322 is included or not.

More specifically, in frontal thoracic fluoroscopy where the body movement of subject P is less than lateral perspective of the thoracic spine, the ratio of the area of the second region of interest 322 to the area of the entire first region of interest 320 is made larger than that of lateral perspective of the thoracic spine. There is. In this case, the difference between the weight value 1 in the first area of interest 320 excluding the second area of interest 322 and the weight value 2 in the second area of interest 322 is also set smaller in the anterior thoracic fluoroscopy than in the lateral thoracic vertebrae. ing. As described above, the setting function 308 makes the area ratio of the second interest region 322 and the entire first interest region 320 different depending on the inspection type. Further, depending on the inspection type, the generation function 310 makes the difference between the weight value 1 in the first interest region 320 excluding the second interest region 322 and the weight value 2 in the second interest region 322 different. .. This makes it possible to suppress fluctuations in the control value for each test type and to perform dose control for each test type more accurately.

Further, in the present embodiment, as shown in FIGS. 5C and 5D, the weight value near 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 increases. That is, in the fluoroscopy on the right side of the thoracic spine 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 fluoroscopy on the left side of the thoracic spine 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 perspective perspective, the distribution of weight values within the first region of interest 320 is asymmetrical. As a result, even if the chest is included in the first region of interest due to body movement or the like, it is suppressed that the pixel value in the chest contributes to the calculation of the control value.

Further, in lateral fluoroscopy of the spinal column system such as the thoracic spine, the first region of interest 320 is also set at a position deviated from the center of the image. For example, as shown in FIG. 5C, when the first region of interest 320 is located at a position shifted to the right from the center of the image, the chest is seen through to the left side of the first region of interest 320. Therefore, 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 interest region 322 in the first interest region 320 according to the inspection type, it is possible to further suppress the fluctuation of the control value caused by the body movement, and it is possible to further suppress the fluctuation of the control value for each inspection type. It is possible to perform dose control more accurately.

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

Here, the weight value is normalized by dividing the value of the weight coefficient by the sum of the values of the weight coefficient. That is, the total value of the weight values assigned to each pixel value in the first interest region 320 and the second interest region 322 is set to be 1.0. By normalizing the weight value in this way, the control value can be treated in the same manner as the pixel value of the X-ray image. Since the pixel value here is proportional to the X dose, the control value is also proportional to the X dose. The "weight value" is a value given to the weight attached to each pixel value when the addition process of adding the pixel values is performed. For example, in the equation (1), (the value of the weighting coefficient / the sum of the values of the weighting coefficient) is the "weighting value". However, for example, if the weighting coefficient value is not divided by (sum of weighting factor values) in equation (1) without normalizing the weighting value, the weighting factor value corresponds to the "weighting value". Will be done. In this way, when calculating the control value, the weight value may or may not be normalized.

Further, in the embodiment here, the effect of improving the S / N ratio is also achieved by weighting each pixel instead of thinning out the pixels. Therefore, it becomes possible to more accurately control the X-ray dose transmitted through the region of interest 324.

The above is the description of the configuration of the X-ray diagnostic apparatus 10 according to the first embodiment, but the series of flow of the fluoroscopic processing in the X-ray diagnostic apparatus 10 according to the first embodiment will be described below.

FIG. 6 is a diagram showing a flowchart showing a series of fluoroscopic flows according to the first embodiment. Step S100 is a step realized by the inspector inputting the inspection type from the input circuit 600. The signal indicating the inspection 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 is a step in which 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 S102, it is determined whether or not the control function ends 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 that 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 that inspection type is continued.

Step S104 is a step corresponding to the control function, and is a step in which 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 the irradiation of X-rays for fluoroscopy. When the irradiation signal is input to the control circuit 406 from the exposure button 500 (YES in step S104), the irradiation of X-rays for fluoroscopy is continued. On the other hand, when the switch of the exposure button 500 is not pressed, the irradiation of X-rays for fluoroscopy is stopped, and the control function performs the process from step S102 (NO in step S104).

Step S106 is a step realized by the F condition determination circuit 404 reading out the dose index according to the inspection type input from the F condition determination table 408 and the input circuit 600 from the second storage circuit 402. In step S106, the F condition determination circuit 404 outputs the default mAs value and the 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 by the control circuit 406 calling and executing a predetermined program corresponding to the control function from the second storage circuit 402. In step S108, the control circuit 406 outputs the fluoroscopic condition signal corresponding to the tube voltage and the mAs value input from the F condition determination circuit 404 to the high voltage generator 102. Further, the control circuit 406 outputs a storage 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 the current corresponding to the mAs value to the X-ray tube 104. Further, the X-ray detector 202 starts the accumulation of electric charges in response to the accumulation signal from the control circuit 406. Subsequently, the X-ray detector 202 outputs an analog X-ray image signal based on the accumulated charge to the AD conversion circuit 204 according to the irradiation time signal input from the control circuit 406 according to the end of the irradiation time. Further, 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 S100, 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 area of interest 320 and the second area of interest 322 in the X-ray image based on the input inspection 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 constant function from the first storage circuit 302. In step S114, the generation function 310 assigns a weight greater than 0 to each pixel value in the first area of interest 320 according to the position in the first area of interest 320, based on the input inspection type. Is added to the addition process, and a control value is generated based on the value obtained in 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 applies gradation conversion to an image suitable for observation on the X-ray image input from the first storage circuit 302, and outputs the X-ray image to the display 700.

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

As described above, in the present embodiment, each pixel value in the first area of interest 320 is given a weight value greater than 0 depending on the position in the first area of interest 320. The addition process was performed by adding, and the control value was generated based on the value obtained by the addition process. This makes it possible to increase the weight given to the pixels in the region of interest 324 in the subject P, and contributes the pixels in the region of interest 324 to the generation of control values used for controlling the X-ray irradiation apparatus 100. Can be increased. Therefore, it is possible to further improve the accuracy of the control value at the time of 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 the fluctuation caused by the body movement. As a result, even if the subject P moves, at least a part of the region of interest 324 is suppressed from being located outside the first region of interest 320, so that the fluctuation of the irradiation dose to the subject P is suppressed. To.

(Modification example)
In the first embodiment described above, the weight value used for the generation function 310 is composed of two values, but in this modification, the weight value used for the generation function 310 is configured with three or more values. I have to. Hereinafter, the parts different from the above-described first embodiment will be described.

The weight values used in the generation function 310 according to the present modification will be described with reference to FIGS. 7A to 7D. FIG. 7A 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 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 on the right. 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 showing weight values when the weight values in the first region of interest 320 change continuously.

The upper view of FIGS. 7A to 7C shows the range of the first interest region 320, the second interest region 322, and the third interest region 326, and the lower figure shows the weight value in the first interest region 320 and the first interest. It is a figure which shows the relationship with the position in the region 320. The upper figure of FIG. 7D is a diagram showing the range of the first interest region 320 and the second interest region 322, and the lower figure is the relationship between the weight value in the first interest region 320 and the position in the first interest region 320. It is a figure which shows. In these figures below, 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. Further, here, the predetermined value th2 is, for example, 1.0, and the region having a weight value of 1.0 or more is the second region of interest 322.

In the first embodiment, for example, as shown 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 modification, as shown in FIGS. 7A to 7C, the setting function 308 sets the third interest region 326 in the first interest region 320, and sets the second interest region 326 in the third interest region 326. 322 is set. In this case, the generation function 310 assigns the weight value of the first stage in the second interest region 322, assigns the weight value of the second stage in the third interest region 326 excluding the second interest region 322, and gives the second stage weight value. A third-stage weight value is assigned to the first region of interest 320 excluding the region of interest 326. In this way, by setting the number of stages, when the region of interest 324 of the subject P moves within the region of interest 320 due to body movement, the fluctuation of the control value (for example, equation (1)) can be made smoother. .. As a result, the fluctuation of the X dose can be made more gentle.

Further, as shown in FIG. 7D, when the value of the weight value is continuously changed, the control value fluctuates when the region of interest 324 of the subject P moves within the first region of interest 320 due to body movement. It is possible to make the fluctuation of the X dose continuous. The weight value shown in FIG. 7D is generated according to an arithmetic expression of a normal distribution centered on, for example, x = XA (mean value). That is, the generation function 310 of the image processing apparatus 300 generates the weight value according to the calculation formula of the normal distribution. In this case, the coordinates having a weight value of 1.0 are set in advance according to the coordinates of the second region of interest 322.

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 fluctuation of the weight value in the first region of interest 320 is made smoother. As a result, when the region of interest 324 of the subject P moves within the first region of interest 320, the fluctuation of the X dose irradiated to the subject P can be made smoother. As a result, the fluctuation 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 inspector inputs the inspection type to the X-ray diagnostic apparatus 10, but in the second embodiment, the fluoroscopy sequence setting function 328 follows the fluoroscopy sequence and sets the inspection type to X-rays. It is designed to be input to the diagnostic device 10. Hereinafter, the parts different from the above-described first embodiment will be described.

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 is different from the first embodiment in that the image processing apparatus 300 further has a fluoroscopy sequence setting function 328. 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 second storage circuit 402. That is, the fluoroscopy sequence setting function 328 is a function for calculating the control value used for controlling the X-ray irradiation apparatus 100, like the pixel value conversion function 306, the setting function 308, and the generation function 310.

The fluoroscopic sequence setting function 328 will be described with reference to FIG. 8 with reference to FIG. FIG. 9 is a diagram showing a part of a series of fluoroscopic movements in myelography of the lumbar spine. (A) is a figure which shows the X-ray image which is seen through the fluoroscope 200 in time series. Further, (b) is a diagram showing a first region of interest 320 and a second region of interest 322 set in time series by the setting function 308 corresponding to the X-ray image. Here, myelography is a clinical test for diagnosing the shape of the spinal cord cavity and the like. In myelography, a contrast medium is injected into the spinal cord cavity and the flow of the contrast medium is observed by fluoroscopy. As described above, in X-ray fluoroscopy, the inspection type to be fluoroscopy in time series may be predetermined. In this case, if the inspector inputs the inspection type from the input circuit 600 in chronological order, the flow of X-ray fluoroscopy may be interrupted.

Therefore, in the present embodiment, as shown in FIG. 8, the first storage circuit 302 stores the order of the inspection types to be seen through in chronological order for each fluoroscopy. Here, the order of the inspection types to be seen through in chronological order is called a fluoroscopy sequence. For example, when the fluoroscopy is a myelography of the lumbar spine, the anterior surface of the thoracic spine, the left side surface of the thoracic spine, the right side surface of the thoracic spine, and the like are stored in chronological order as the fluoroscopy sequence. Further, for example, when the fluoroscopy is gastroscopy fluoroscopy, the anterior surface of the abdomen, the side surface of 10 degrees to the right of the abdomen, the side surface of 30 degrees to the right of the abdomen, and the like are stored in chronological order as the fluoroscopy sequence. The first storage circuit 302 stores a fluoroscopic sequence for each fluoroscopic examination such as lumbar myelography, cervical spine myelography, gastric angiography, bile duct angiography, and urinary system angiography.

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

An example of fluoroscopy using the fluoroscopy sequence setting function 328 will be described with reference to FIG. FIG. 10 is a diagram showing a flowchart showing a series of flows in fluoroscopy using the fluoroscopy sequence setting function 328. The same processing as in FIG. 6 in the first embodiment is assigned the same number, and the description thereof will be omitted if it is not necessary.

Step S120 is a step realized by the inspector inputting the type of fluoroscopy from the input circuit 600. The fluoroscopy inspection type input in step S120 is input to the fluoroscopy 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 fluoroscopy sequence setting function 328 reads out the fluoroscopy sequence input from the input circuit 600 from the first storage circuit 302, and sets the inspection type shown in the fluoroscopy sequence as the F condition determination circuit 404 according to the progress of fluoroscopy. , 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 at the end of a series of processes.

Step S100 is a step of inputting an inspection type as in FIG. 6 in the first embodiment. Here, step S100 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 fluoroscopy sequence setting function 328 outputs the inspection type shown in the fluoroscopy 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 chronological order is output in order.

Step S124 is a step corresponding to the control function, and is a step in which 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 S128, it is determined whether or not to end a series of examinations based on the type of fluoroscopy examination. When the inspection type is input from the fluoroscopy sequence setting function 328 (NO in step S124), a series of inspections are continued and the processing from step S100 is performed. On the other hand, when the end signal is input from the fluoroscopy sequence setting function 328 (NO in step S124), the series of inspections is terminated.

As described above, in the present embodiment, when the fluoroscopy sequence setting function 328 inputs the type of fluoroscopy, the first interest region 320 and the second interest region 322 follow the fluoroscopy sequence according to the fluoroscopy inspection. It was decided to automatically change the position of for each inspection type. As a result, the inspector does not have to input the inspection type, and the operability can be improved.

The X-ray irradiation device 100 in the first embodiment is an example of an X-ray irradiation unit in the claims, and the collection device 200 is an example of an acquisition unit in the claims. The setting function 308 in the first embodiment is an example of a setting unit within the scope of claims. Further, the setting function 308 in the modified example of the first embodiment is another example of the setting unit in the scope of claims. The generation function 310 in the first embodiment is an example of a generation unit within the scope of claims. Further, the generation function 310 in the modified example of the first embodiment is another example of the generation unit within the scope of 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 fluoroscopy sequence setting function 328 in the second embodiment is an example of a sequence setting unit within the scope of claims. The display 700 in the first embodiment is an example of an image display unit within the scope of claims.

The term "processor" used in the above description refers to, 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 (Single Programmable Logic Device: SPLD), composite programmable logic device (Complex Programmable Logic Device: CPLD), field programmable gate array (Field Programmable Gate Array: FPGA), etc. The processor realizes the function by reading and executing the program stored in the storage circuit. Instead of storing the program in the storage circuit, the program may be directly embedded in the circuit of the processor. In this case, the processor realizes the function by reading and executing the program embedded in the circuit. It should be noted that each processor of the present embodiment is not limited to the case where each processor is configured as a single circuit, and a plurality of independent circuits may be combined to form one processor to realize its function. good. Further, the plurality of components in FIGS. 1, 8 and 11 may be integrated into one processor to realize the function.

Although some embodiments have been described above, these embodiments are presented only as examples and are not intended to limit the scope of the invention. The novel devices, methods and systems described herein can be implemented in a variety of other forms. In addition, various omissions, substitutions, and changes can be made to the apparatus, method, and form of the system described in the present specification without departing from the gist of the invention. The appended claims and their equivalent scope are intended to include such forms and variations contained in the scope and gist of the invention.

10: X-ray diagnostic device, 100: X-ray irradiation device, 200: collection device, 300: image processing device, 308: setting function, 310: generation function, 314: first gradation processing function, 320: first region of interest 322: Second area of interest, 324: Area of interest in the subject, 328: Perspective sequence setting function, 400: Control device, 700: Display, P: Subject

Claims (4)

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 that has passed through the subject in response to irradiation by the X-ray irradiation unit, and an acquisition unit.
A region used for controlling the X-ray irradiation unit, the predetermined region in the X-ray image is included in the first interest region as a region changed by the body movement of the subject and the first interest region. A setting unit for setting a second region of interest having a size based on the predetermined region in the X-ray image, and a setting unit.
The second interest region is weighted larger than the region other than the second interest region in the first interest region, and the pixel value in the first interest region of the X-ray image acquired by the acquisition unit. Pixel value conversion unit that converts
A generation unit that generates a control value based on the pixel value in the first region of interest in which the pixel value is converted,
A control unit that controls the X-rays emitted by the X-ray irradiation unit so that the control value approaches a predetermined value, and a control unit.
X-ray diagnostic device. The X-ray diagnosis according to claim 1 , wherein the weight values of the first region of interest and the second region of interest, and the weight values of the first region of interest and the second region of interest are preset for each examination type. Device. The first or second aspect of the present invention, wherein the control unit controls the tube voltage supplied to the X-ray irradiation unit and the current corresponding to the mAs value so that the control value approaches the dose index determined by the inspection type. X-ray diagnostic device. The irradiation process of irradiating the subject with X-rays and
An acquisition step of repeatedly acquiring an X-ray image of the X-ray that has passed through the subject in response to the irradiation of the X-ray, and an acquisition step.
A region used for controlling the X-ray , and the predetermined region in the X-ray image is included in the first region of interest as a region changed by the body movement of the subject and the predetermined region of interest . A setting step of setting a second region of interest having a size based on the region in the X-ray image, and
The second interest region is weighted larger than the region other than the second interest region in the first interest region, and the pixel value in the first interest region of the X-ray image acquired in the acquisition step. Pixel value conversion process to convert
A generation step of generating a control value based on a pixel value in the first region of interest in which the pixel value is converted, and a generation step.
A control step that controls the X-rays so that the control value approaches a predetermined value, and
A control method for an X-ray diagnostic apparatus comprising.

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