JP2018126447A - X-ray diagnostic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate visual recognition of display according to a radiation condition of an X-ray.SOLUTION: An X-ray diagnostic apparatus of the embodiment comprises: a support mechanism for movably supporting an X-ray tube and an X-ray detection device; a bed; a dose measurement part; a dose determination part; a dose distribution generation part; and a display control part. The dose measurement part measures a cumulative dose of the X-ray generated over plural times in a prescribed period. The dose determination part determines plural doses corresponding to generation of the X-ray in the prescribed period respectively, based on the cumulative dose and an X-ray radiation condition. The dose distribution generation part generates a dose distribution including a radiation field of the X-ray. The display control part displays the radiation field and the dose distribution of the X-ray on a patient model, on a display part, according to the radiation condition of the X-ray, in a manner in which a display mode related to at least one of a locus of the X-ray and information related to the dose of the X-ray which is radiated, is changed.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to an X-ray diagnostic apparatus.

  In general, the X-ray diagnostic apparatus has a dose distribution function such as a DTS (dose tracking system) as a function of estimating a skin exposure dose indicating a cumulative value of a dose on the surface of a patient (subject). This type of dose distribution function was obtained by calculating the patient's skin dose distribution based on the X-ray irradiation conditions and geometric conditions of the X-ray diagnostic apparatus during the interventional radiology (IVR) procedure. The distribution of the skin exposure dose and the current X-ray irradiation field can be displayed in color on the patient model.

JP 2008-279117 A

  However, the X-ray diagnostic apparatus as described above is usually not particularly problematic, but according to the study of the present inventor, it is considered that there is room for improvement in the following points.

  For example, when the X-ray irradiation field is small, it may be difficult to visually recognize the irradiation field display. For example, when the dose of X-rays to be irradiated is high, it may be difficult to visually recognize that the dose is high from the screen. That is, it is considered that there is room for improvement in that the display may be difficult to visually recognize depending on the X-ray irradiation state.

  The object is to provide an X-ray diagnostic apparatus capable of making the display easy to visually recognize according to the X-ray irradiation state.

  The X-ray diagnostic apparatus according to the embodiment includes a support mechanism, a bed, a dose measurement unit, a dose determination unit, a dose distribution generation unit, and a display control unit.

  The support mechanism movably supports an X-ray tube that generates X-rays irradiated to the subject and an X-ray detection device that detects X-rays transmitted through the subject.

  The bed has a top plate on which the subject is placed.

  The dose measuring unit measures the cumulative dose of the X-ray generated multiple times within a predetermined period.

  The dose determining unit determines a plurality of doses respectively corresponding to the generation of the X-rays in the predetermined period based on the accumulated dose and X-ray irradiation conditions.

  The dose distribution generation unit generates a dose distribution including the X-ray irradiation field based on the position of the support mechanism, the position of the bed, and the dose.

  The display control unit causes the display unit to display the X-ray irradiation field and the dose distribution on a patient model according to the X-ray irradiation state. The display mode concerning at least one of the information regarding the dose is changed and displayed.

FIG. 1 is a schematic diagram showing the configuration of the X-ray diagnostic apparatus according to the first embodiment. FIG. 2 is a schematic diagram showing an appearance of the X-ray diagnostic apparatus according to the embodiment. FIG. 3 is a schematic diagram showing a dose readout cycle and the like in the same embodiment. FIG. 4 is a diagram illustrating the tube voltage (kV) dependence of the dose ratio K (kV) in the same embodiment for each filter thickness. FIG. 5 is a diagram showing an example in which the accumulated area dose is divided into area doses in the embodiment. FIG. 6 is a flowchart for explaining the operation in the embodiment. FIG. 7 is a schematic diagram illustrating an example of a display screen in the embodiment. FIG. 8 is a schematic diagram illustrating another example of the display screen in the embodiment. FIG. 9 is a schematic diagram for explaining setting information used for display control of the X-ray diagnostic apparatus according to the second embodiment. FIG. 10 is a flowchart for explaining the operation in the embodiment. FIG. 11 is a schematic diagram illustrating an example of a display screen in the embodiment. FIG. 12 is a schematic diagram illustrating another example of the display screen in the embodiment. FIG. 13 is a schematic diagram illustrating a display screen according to a modification of the embodiment. FIG. 14 is a flowchart for explaining the operation of another modification of the embodiment.

  Each embodiment will be described below with reference to the drawings, but before that, an outline of each embodiment will be described. An outline of each embodiment relates to an X-ray diagnostic apparatus that makes it easy to visually recognize a dose distribution function that displays a dose distribution including an X-ray irradiation field in accordance with an X-ray irradiation state during X-ray irradiation. . Here, 1st Embodiment is an example which makes it easy to visually recognize by magnifying and displaying an irradiation field and its periphery according to the irradiation condition that an irradiation field is small. The second embodiment is an example in which the X-ray trajectory or the dose rate is highlighted and displayed easily according to the irradiation state that the dose rate is high. The first and second embodiments are not limited to the description of this outline, and may be combined with each other. The above is the outline of each embodiment. Subsequently, each embodiment will be specifically described.

<First Embodiment>
FIG. 1 shows a configuration of an X-ray diagnostic apparatus 1 according to the present embodiment. The X-ray diagnostic apparatus 1 includes a high voltage generator 3, an X-ray tube 5, an X-ray detector 7, a support mechanism 9, an irradiation range limiter 11, a dose measuring device 13, and a top plate 151. The bed 15, the drive unit 17, the image generation circuit 19, the communication interface circuit 21, the storage circuit 23, the area dose determination circuit 25, the dose distribution generation circuit 27, the input interface circuit 29, and the display circuit 31 The display control circuit 32 and the control circuit 33 are included. In FIG. 1, “I / F” is an abbreviation for “interface”.

  FIG. 2 is a schematic diagram showing an appearance of the X-ray diagnostic apparatus 1 according to the present embodiment.

  The high voltage generator 3 generates a tube current supplied to the X-ray tube 5 and a tube voltage applied to the X-ray tube 5. The high voltage generation unit 3 supplies tube currents suitable for X-ray imaging and X-ray fluoroscopy to the X-ray tube 5 according to the X-ray irradiation conditions described later under the control of the control circuit 33 described later. A tube voltage suitable for each of radiography and X-ray fluoroscopy is applied to the X-ray tube 5.

  For example, the high voltage generator 3 applies a tube voltage to the X-ray tube 5 a plurality of times during a dose measurement period in the dose meter 13 described later in the X-ray fluoroscopy with respect to the subject P, and generates a tube current. The X-ray tube 5 is supplied. As a result, the X-ray tube 5 generates X-rays a plurality of times within a predetermined period (dose measurement period). Hereinafter, the time during which the subject P is irradiated with X-rays in the dose measurement period is referred to as irradiation time. Further, the interval at which the subject P is irradiated with X-rays during the dose measurement period is referred to as an irradiation interval. The “subject” may be called a “patient”.

  The X-ray tube 5 is based on the tube current supplied from the high voltage generation unit 3 and the tube voltage applied by the high voltage generation unit 3 from the X-ray focus (hereinafter referred to as the tube focus). X-rays that irradiate the subject P are generated. X-rays generated from the tube focus are applied to the subject P through an X-ray emission window provided in front of the X-ray tube 5.

  The X-ray detection apparatus 7 is a planar X-ray detector 71 that converts X-rays that have passed through the subject P into charges and stores them, and X-rays with higher definition (higher resolution) than the X-ray detector 71. And a high-definition detector 72 capable of detecting. For example, as shown in FIG. 2, such an X-ray detection apparatus 7 has a high-definition detector 72 at the tip of the arm 97, and the base end of the arm 97 can be rotated in the vicinity of the X-ray detector 71. The two detectors 71 and 72 may be switchable by a shaft-supported configuration. In this case, for example, the base end of the arm 97 is arranged in front of the X-ray detector 71 in the mode using the high-definition detector 72, and is high-definition in the mode not using the high-definition detector 72. The driving mechanism (not shown) is controlled so as to retract the detector 72. Note that a mode using the high-definition detector 72 may be referred to as a MAF (Micro Angiographic Fluoroscope) mode.

  The X-ray detector 71 detects X-rays generated from the X-ray tube 5 and transmitted through the subject P. For example, the X-ray detector 71 has a flat panel detector (hereinafter referred to as FPD). The size of the FPD is generally 8-12 inches. The FPD is configured by two-dimensionally arranging minute semiconductor detection elements in a column direction and a line direction. The semiconductor detection element includes a direct conversion type and an indirect conversion type. The direct conversion type is a type in which incident X-rays are directly converted into electrical signals. The indirect conversion form is a form in which incident X-rays are converted into light by a phosphor and the light is converted into an electrical signal.

  Electrical signals generated by a plurality of semiconductor detection elements with the incidence of X-rays are output to an analog-to-digital converter (hereinafter referred to as an A / D converter) (not shown). The A / D converter converts an electrical signal into digital data. The A / D converter outputs the digital data to a preprocessing unit (not shown). Note that an image intensifier may be used as the X-ray detector 71.

  The high-definition detector 72 is an X-ray detector that can be used by switching from the X-ray detector 71, and is an X-ray detector having a higher spatial resolution than the X-ray detector 71. For example, the high-definition detector 72 has a larger number of detection elements per unit area than the X-ray detector 71, and usually indicates a detector having four or more detection elements. The high-definition detector 72 has a detection area of 4 to 6 inches smaller than the X-ray detector 71. The high-definition detector 72 has a configuration in which a scintillator is formed on a CCD (Charge Coupled Device) formed on a single crystal Si substrate, for example. A CCD is a form of an image sensor, and when X-rays are incident on a single crystal Si substrate, charges are generated in accordance with the incident X-ray dose. Further, the high-definition detector 72 may be configured using a complementary metal-oxide-semiconductor (CMOS) image sensor instead of the CCD. A CMOS is also a form of an image sensor, and when X-rays are incident on a single crystal Si substrate as in the CCD, charges are generated in accordance with the incident X-ray dose. Further, in the CMOS, the generated electric charge is accumulated as a capacity, converted into a voltage component and output.

  The support mechanism 9 supports the X-ray tube 5 and the X-ray detection device 7 so as to be movable. Specifically, the support mechanism 9 includes, for example, a C arm 91, an arm support portion 93, and an arm holder 95 as shown in FIG. The C arm 91 mounts the X-ray tube 5 and the X-ray detection device 7 so as to face each other. An Ω arm may be used instead of the C arm 91. The arm support portion 93 supports the C arm 91 so as to be slidable in a direction along the C shape of the C arm (hereinafter referred to as a first direction).

  Further, the arm support portion 93 is rotatable about the arm holder 95 that connects the C arm 91 and the arm support portion 93 substantially in the direction orthogonal to the first direction (hereinafter referred to as the second direction). 91 is supported. The arm support portion 93 is a C arm 91 that can move in parallel in a short axis direction (X direction in FIGS. 1 and 2) and a long axis direction (Y direction in FIGS. 1 and 2) of a top plate 151 to be described later. It is also possible to support. The C-arm 91 can change the distance between the tube focus in the X-ray tube 5 and the X-ray detection device 7 (source image distance (hereinafter referred to as SID)). The tube 5 and the X-ray detection device 7 are supported. The SID is the distance between the tube focus in the X-ray tube 5 and the high-definition detector 72 in the MAF mode using the high-definition detector 72, and the tube focus in the X-ray tube 5 in the other modes. And the X-ray detector 71.

  Note that the support mechanism 9 in the X-ray diagnostic apparatus 1 according to the present embodiment is not limited to the structure of the C arm 91. The support mechanism 9 may be supported so as to be movable in an arbitrary direction by, for example, two arms (for example, robot arms) that respectively support the X-ray tube 5 and the X-ray detection device 7. Further, the support mechanism 9 may be an Ω arm suspended from the ceiling instead of the C arm 91. Further, the support mechanism 9 may have a biplane structure. Further, the support mechanism 9 in the X-ray diagnostic apparatus 1 according to the present embodiment is not limited to an over tube system, an under tube system, and the like, and can be applied to any form.

  The irradiation range limiter 11 is provided in front of the X-ray emission window in the X-ray tube 5. That is, the irradiation range limiter 11 is provided between the X-ray tube 5 and an X-ray detection device 7 described later. The irradiation range limiter 11 is also referred to as an X-ray movable diaphragm. Specifically, the irradiation range limiter 11 prevents the X-rays generated at the tube focal point from being exposed to unnecessary exposure other than the imaging region desired by the operator, so that the irradiation range of the maximum aperture (hereinafter referred to as maximum irradiation). (Referred to as a range) is limited according to the irradiation area for irradiating the body surface of the subject P with X-rays. For example, the irradiation range limiter 11 limits the irradiation range by moving the diaphragm blades according to the irradiation range limitation instruction input by the input interface circuit 29 described later.

  Specifically, the irradiation range limiter 11 includes a plurality of first diaphragm blades that can move in a predetermined direction and a plurality of second diaphragm blades that can move in a direction different from the predetermined direction. Each of the first and second diaphragm blades is made of lead that shields X-rays generated at the tube focus.

  The irradiation range limiter 11 is provided with a plurality of predetermined filters (hereinafter also referred to as radiation quality adjustment filters) inserted into the X-ray irradiation field for the purpose of reducing the exposure dose to the subject P and improving the image quality. You may have. The irradiation range limiter 11 is not limited to the quality control filter, but is a compensation filter for preventing halation due to X-rays, or an ROI (region of interest) that attenuates and transmits X-rays outside the aperture region. ) You may have a filter. The plurality of quality control filters have different thicknesses. Note that the quality control filters may be made of different materials and may have the same thickness. The quality control filter changes the quality of X-rays generated at the tube focus according to the thickness. The quality control filter is made of, for example, aluminum or copper. The quality control filter is selected by the operator via the input interface circuit 29 according to the imaging plan for the subject P. The quality control filter selected from the plurality of quality control filters is inserted into the X-ray irradiation field in the irradiation range limiter 11 under the control of the control circuit 33 described later.

  The quality control filter reduces, for example, low-energy X-ray components (soft line components) that are easily absorbed by the subject P among X-rays generated at the tube focus (hereinafter referred to as generated X-rays). Further, the radiation quality adjustment filter may reduce high energy X-ray components that cause a decrease in contrast in a medical image generated by an image generation circuit 19 described later, among the generated X-rays.

  The compensation filter is made of a metal plate or the like, and is inserted into an X-ray irradiation field to attenuate the X-rays to reduce exposure and prevent halation due to X-rays.

  The ROI filter is located between the X-ray tube 5 and the first and second diaphragm blades, and is composed of a metal plate such as copper or aluminum. The ROI filter has an opening region at least partially, for example, in the center, and attenuates X-rays outside the opening region. For this reason, the ROI filter totally transmits X-rays in the X-ray passing region of the opening region, and attenuates and transmits X-rays in other regions.

  The dose measuring device 13 is an example of a dose measuring unit that measures a cumulative dose of X-rays generated a plurality of times within a predetermined period, and is provided in front of the irradiation range limiter. That is, the dose measuring device 13 is an example of a dose measuring unit, and is provided between the irradiation range limiter 11 and the X-ray detection device 7. The dose measuring device 13 is, for example, an area dosimeter. The dose measuring device 13 measures an integrated value of area dose over a predetermined period (hereinafter referred to as cumulative area dose (cumulative dose)). The predetermined period is a dose measurement period. The dose measurement period corresponds to a read cycle (hereinafter referred to as a dose read cycle) in which the accumulated area dose measured by the dose meter 13 is read from the dose meter. The dose measuring device 13 outputs the accumulated area dose read for each dose reading cycle to the area dose determining circuit 25 and the storage circuit 23 described later.

  Note that the dose measuring unit does not necessarily need to use the dose measuring device 13 for actually measuring the dose. For example, a processing circuit that estimates a dose may be used as the dose measuring unit, and for example, a processor that reads and executes a program for estimating a dose from the storage circuit 23 may be used. In this case, the dose measurement unit may measure the cumulative dose of X-rays by estimating the skin dose based on the X-ray irradiation conditions, for example. As such a skin dose estimation method, for example, an NDD (Numerical Dose Determination) method or an EPD (Estimation of Patient Dose in diagnostic X-ray examination) can be used as appropriate. The “NDD method” may also be called “Non Dosimeter Dosimetry method”. Examples of X-ray irradiation conditions related to dose measurement include information on tube current, tube voltage, irradiation time, distance to the subject P, images, and the like, and are stored as appropriate according to an estimation method such as the NDD method or EPD method. It is read out from the circuit 23 to the dose measuring unit and used.

  FIG. 3 is a diagram showing a dose readout period in the dose meter 13 together with the accumulated area dose, the irradiation time, and the irradiation interval read from the dose meter 13. Hereinafter, in order to simplify the description, the number of times the subject P is irradiated with X-rays (hereinafter referred to as the number of times of irradiation) in the dose readout cycle is set to five times. Note that the number of irradiations is not limited to five, and may be any number of two or more.

  The couch 15 has a top plate 151 (also referred to as a prone table) on which the subject P is placed. The subject P is placed on the top plate 151.

  The drive unit 17 drives the support mechanism 9 and the bed 15 under the control of the control circuit 33 described later. Specifically, the drive unit 17 supplies a drive signal corresponding to the control signal from the control circuit 33 to the arm support unit 93, slides the C arm 91 in the first direction, and the second direction (CRA or CAU). Rotate to During X-ray fluoroscopy and X-ray imaging, the subject P placed on the top plate 151 is disposed between the X-ray tube 5 and the X-ray detection device 7. The drive unit 17 outputs the position of the X-ray tube 5 with respect to the top plate 151 (or the position of the support mechanism 9) to a dose distribution generation circuit 27 and a storage circuit 23 described later.

  The drive unit 17 moves the top plate 151 by driving the top plate 151 under the control of the control circuit 33 described later. Specifically, based on a control signal from the control circuit 33, the driving unit 17 determines the short axis direction (X direction in FIGS. 1 and 2) of the top plate 151 or the long axis direction (FIG. 1, FIG. 1). The top plate 151 is slid in the Y direction in FIG. Moreover, the drive part 17 raises / lowers the top plate 151 regarding a perpendicular direction (Z direction of FIG. 1, FIG. 2). In addition, the drive unit 17 rotates the top plate 151 to tilt the top plate 151 with at least one of the major axis direction and the minor axis direction as a rotation axis (X axis, Y axis in FIG. 1). May be. The drive unit 17 outputs the position of the top plate 151 to a dose distribution generation circuit 27 described later.

  The drive unit 17 outputs the relative positional relationship between the X-ray tube 5 and the top plate 151 to a dose distribution generation circuit 27 described later. The relative positional relationship between the X-ray tube 5 and the top plate 151 includes, for example, an angle (inclination) of the C arm 91 with respect to the top plate 151, a slide angle of the C arm 91, and the like (referred to as an arm angle). . The inclination and the arm angle are, for example, Euler angles based on an isocenter with respect to the subject. Note that the drive unit 17 may drive the X-ray detector 71 in order to arbitrarily rotate it according to the position of the support mechanism 9, the angle of the C arm 91, and the like.

  A preprocessing unit (not shown) performs preprocessing on the digital data output from the X-ray detector 71. Pre-processing includes correction of non-uniform sensitivity between channels in the X-ray detector 71 and correction related to an extreme decrease in signal or data loss due to an X-ray strong absorber such as metal. The preprocessed digital data is output to an image generation circuit 19 described later.

  The image generation circuit 19 generates a captured image based on digital data preprocessed after X-ray imaging at the imaging position. The image generation circuit 19 generates a fluoroscopic image based on digital data pre-processed after X-ray fluoroscopy at the fluoroscopic position. Hereinafter, the captured image and the fluoroscopic image are collectively referred to as a projected image. The image generation circuit 19 outputs the generated projection image to the display circuit 31 and the storage circuit 23 described later.

  The communication interface circuit 21 is, for example, an interface related to a network and an external storage device (not shown). Data such as projection images and analysis results obtained by the X-ray diagnostic apparatus 1 can be transferred to other apparatuses via the communication interface circuit 21 and the network.

  The storage circuit 23 includes a memory for recording electrical information such as an HDD (Hardware Disk Drive), and peripheral circuits such as a memory controller and a memory interface associated with the memory. Here, the storage circuit 23 has various projection images generated by the image generation circuit 19, a control program of the X-ray diagnostic apparatus 1, a diagnostic protocol, an operator instruction sent from the input interface circuit 29 described later, Various data groups such as imaging conditions and fluoroscopic conditions, various data transmitted via the communication interface circuit 21 and the network, accumulated area dose, and the like are stored. The storage circuit 23 may store a relative positional relationship between the X-ray tube 5 and the top plate 151.

  Specifically, the storage circuit 23 stores X-ray irradiation conditions for each X-ray irradiation (generation) on the subject. The X-ray irradiation conditions are conditions related to radiation quality (tube voltage, tube current, etc.), irradiation time, irradiation interval, opening in the irradiation range limiter 11, product of tube current (mA) and irradiation time (s) (hereinafter, Tube current time product (mAs)), the thickness of the quality control filter selected via the input interface circuit 29 (or the type of quality control filter), and the number of X-ray irradiations (occurrence) during the dose measurement period. Imaging field of view (FOV), irradiation rate (number of X-ray irradiations per second), and the like. The X-ray irradiation conditions are appropriately changed according to, for example, the thickness of the subject regarding the imaging region. Among the X-ray irradiation conditions, the thickness (type) of the quality control filter, the irradiation time, the irradiation rate, and the like are appropriately set in advance via the input interface circuit 29 described later.

  The storage circuit 23 stores geometric conditions for each irradiation (generation) of X-rays on the subject. The geometric conditions include a predetermined reference position, the position of the top plate 151, the position of the C arm 91, the angle of the C arm 91, the SID, the FPD rotation angle, and the like. The predetermined reference position is, for example, a position 15 cm away from the isocenter in the X-ray diagnostic apparatus 1 toward the tube focus. The storage circuit 23 may store a correspondence table of irradiation areas at the reference position and the reference position with respect to the opening. The storage circuit 23 stores an irradiation area for each X-ray irradiation.

  The storage circuit 23 stores a patient model used in a dose distribution generation circuit 27 described later. The storage circuit 23 may store a dose distribution generation program for generating a dose distribution at a predetermined reference position. The storage circuit 23 stores the dose distribution generated by the dose distribution generation circuit 27. The storage circuit 23 stores X-ray irradiation conditions, geometric conditions, and dose distributions corresponding to each of the multiple generations (irradiation) of X-rays over the dose measurement period. The irradiation conditions, geometric conditions, and dose distribution may be updated and stored.

  The storage circuit 23 may store the X-ray irradiation condition and the geometric condition as an irradiation history for each X-ray irradiation. The storage circuit 23 stores the relationship of the dose ratio K (kV) to the tube voltage (kV) corresponding to the thickness (or type) of the plurality of quality control filters.

  The area dose determining circuit 25 determines a plurality of area doses (dose) respectively corresponding to a plurality of times of X-ray irradiation (generation) in the dose reading period based on the accumulated area dose and the X-ray irradiation conditions. That is, the area dose determination circuit 25 determines the area dose for each output of the accumulated area dose (every dose measurement period). The area dose determination circuit 25 outputs the determined plurality of area doses together with the corresponding irradiation area to the dose distribution generation circuit 27.

  Specifically, the area dose determination circuit 25 reads the X-ray irradiation conditions from the storage circuit 23. The area dose determination circuit 25 determines the irradiation area at the reference position based on the opening and the reference position. The area dose determination circuit 25 may determine the irradiation area based on the opening and the correspondence table.

  Next, the area dose determining circuit 25 determines the unit tube current time product and the dose per unit area (based on the tube quality and the thickness of the quality control filter (or the type of quality control filter) and the tube voltage among the X-ray irradiation conditions. Hereinafter, the dose ratio K is determined. In general, tube voltage is not proportional to dose. For this reason, in order to make the tube voltage proportional to the dose, a predetermined conversion is required. The dose ratio K obtained by converting the tube voltage by a predetermined conversion is proportional to the dose.

  FIG. 4 is a diagram showing an example of the relationship of the dose ratio K (kV) to the tube voltage (kV) (hereinafter referred to as the tube voltage dose ratio relationship) for each of the thicknesses of a plurality of predetermined filters (wire quality adjustment filters). It is. As shown in FIG. 4, the relationship between the tube voltage and the dose ratio K depends on the thickness of the quality control filter inserted into the X-ray irradiation field by the irradiation range limiter 11. In other words, the thinner the quality control filter, the greater the slope in the tube voltage dose ratio relationship as shown in FIG. In addition, the thicker the quality control filter, the smaller the slope in the tube voltage dose ratio relationship as shown in FIG. Similarly, for the compensation filter and the ROI filter, the relationship between the tube voltage and the dose ratio K depends on the thickness of each filter inserted in the X-ray irradiation field by the irradiation range limiter 11.

  The area dose determination circuit 25 calculates a ratio of a plurality of area doses to the cumulative area dose (hereinafter referred to as an area dose ratio (dose ratio)) based on the dose ratio, the tube current time product, and the irradiation area. Decide for each. Specifically, the area dose determination circuit 25 integrates the multiplication value obtained by multiplying the dose ratio K, the tube current time product, and the irradiation area in the dose measurement period over the generation of a plurality of X-rays in the dose measurement period. Calculate the integrated value. Next, the area dose determination circuit 25 calculates an area dose ratio by dividing each of a plurality of multiplication values related to irradiation (generation) of X-rays by the integrated value.

For example, the dosimetry period, the dose ratio K K _i in generation of the i-th _X-ray, mAs i the tube current time _product, when the irradiation area S _i, multiplying values in the generation of the i-th X-rays, K _i × mAs _i × S _i . If the number of generation (irradiation) of X-rays during the dose measurement period is n, the integrated value and the area dose ratio are calculated as shown in the following equations.

  Hereinafter, in order to simplify the explanation, it is assumed that the number of X-ray generation (irradiation) in the dose measurement period is 5 (n = 5).

  By the above calculation, the area dose determination circuit 25 determines a plurality of area doses in the dose measurement period by multiplying each of a plurality of area dose ratios corresponding to a plurality of X-ray generations by the accumulated area dose. That is, the area dose corresponding to the generation of the i-th X-ray during the dose measurement period is determined by multiplying the area dose ratio of the above-described mathematical formula by the accumulated area dose. From the above, the area dose determination circuit 25 can divide the accumulated area dose in the dose measurement period into the area dose for each occurrence (irradiation) of a plurality of X-rays in the dose measurement period.

  FIG. 5 is a diagram illustrating an example in which the accumulated area dose is divided into area doses for each occurrence (irradiation) of a plurality of X-rays in the dose measurement period. As shown in FIG. 5, the accumulated area dose in the dose measurement period is divided into area doses for each generation (irradiation) of X-rays in the dose measurement period.

  When the imaging region differs for each X-ray irradiation, for example, as shown in FIG. The difference in the area dose for each X-ray irradiation is caused by, for example, a difference in X-ray irradiation conditions due to a difference in the thickness of the subject for each imaging region. In addition, when the imaging | photography site | part for every X-ray irradiation is the same, unlike FIG. 5, for example, the area dose for every X-ray irradiation is substantially equal, respectively. The substantially equivalent area dose is attributed to, for example, that the X-ray irradiation condition and the geometric condition are substantially equal for each X-ray irradiation.

  When the accumulated area dose is output for each dose measurement period, the area dose determination circuit 25 divides the output accumulated area dose into area doses for each X-ray irradiation. The area dose determination circuit 25 outputs the area dose divided for each dose measurement period to a dose distribution generation circuit 27 described later. The area dose determining circuit 25 may determine the area dose for each X-ray irradiation based on the irradiation history and the accumulated area dose.

  The dose distribution generation circuit 27 generates a dose distribution including an X-ray irradiation field based on the position of the support mechanism 9, the position of the bed 15, and the dose. For example, the dose distribution generation circuit 27 generates a dose distribution at a predetermined reference position based on the position of the support mechanism 9, the position of the bed 15, a plurality of area doses, and an irradiation area. Specifically, the dose distribution generation circuit 27 generates a dose distribution based on a plurality of area doses, an irradiation area, and the position of the support mechanism and the relative positional relationship. That is, the dose distribution generation circuit 27 generates a dose distribution for each dose measurement period.

  When the dose distribution is stored in the storage circuit 23, the dose distribution generation circuit 27 generates a dose distribution obtained by adding the generated dose distribution to the stored dose distribution. Thereby, the dose distribution generation circuit 27 updates the dose distribution for each output of the accumulated area dose (for each dose measurement period). The dose distribution generation circuit 27 outputs the dose distribution to a display circuit 31 and a storage circuit 23 described later.

  Specifically, the dose distribution generation circuit 27 is based on the relative positional relationship (geometric condition) with the position of the support mechanism 9, the plurality of area doses, and the irradiation area, and the air kerma at the reference position. Calculate The dose distribution generation circuit 27 reads the patient model from the storage circuit 23. For example, a plurality of patient models may be stored in the storage circuit 23 according to a plurality of types of body types, and a patient model having a body type close to that of the subject (patient) may be selectively read out. The body shape may be defined by, for example, a combination of a height range and a weight range. In this case, the patient model may be selected by the operator, or the dose distribution generation circuit 27 may select based on the height and weight of the subject. The “patient model” may be called a “subject model”. Based on the calculated air kerma, the irradiation area, the position of the support mechanism 9 and the relative positional relationship (geometric condition), the dose distribution generation circuit 27 determines the dose at the irradiation position on the patient model ( Calculate patient skin dose).

  The dose distribution generation circuit 27 can calculate the patient skin dose in consideration of the influence of the backscattered rays when calculating the patient skin dose from the air kerma. The dose distribution generation circuit 27 generates a dose distribution by mapping the patient skin dose to the irradiation position in the patient model.

  The input interface circuit 29 inputs an X-ray imaging condition desired by the operator, an X-ray irradiation condition such as an X-ray fluoroscopic condition, a fluoroscopic / imaging position, an irradiation range, and the like according to the operation of the operator. . Specifically, the input interface circuit 29 captures various instructions / commands / information / selections / settings from the operator into the X-ray diagnostic apparatus 1. The fluoroscopic / photographing position is defined by an angle with respect to the isocenter, for example. For example, the origin of the first oblique direction (RAO), the second oblique direction (LAO), the caudal direction (CRA), and the caudal direction (CAU) is set as the fluoroscopic / photographing position, and the origin of the three orthogonal axes in FIG. Assuming that it is an isocenter, the angle of the perspective position at the starting point is 0 °.

  The input interface circuit 29 includes a trackball for setting a region of interest (ROI), a switch button, a mouse, a keyboard, a touch pad for performing an input operation by touching an operation surface, and a display screen and a touch pad. This is realized by an integrated touch panel display or the like. The input interface circuit 29 is connected to the display control circuit 32 and the control circuit 33, converts the input operation received from the operator into an electrical signal, and outputs it to the display control circuit 32 or the control circuit 33. In this specification, the input interface circuit 29 is not limited to the one having physical operation parts such as a mouse and a keyboard. For example, an electric signal processing circuit that receives an electric signal corresponding to an input operation from an external input device provided separately from the apparatus and outputs the electric signal to the display control circuit 32 or the control circuit 33 is also an input interface circuit. It is included in 29 examples.

  The display circuit 31 includes a plurality of displays that display medical images, internal circuits that supply display signals to the displays, and peripheral circuits such as connectors and cables that connect the displays and the internal circuits. . The display circuit 31 displays the projection image generated by the image generation circuit 19 on one display. The display circuit 31 is controlled by the display control circuit 32 and displays the dose distribution including the X-ray irradiation field on the other display together with the patient model. Specifically, the display circuit 31 displays a superimposed image in which the dose distribution is superimposed on the patient model. The display circuit 31 may display an input screen related to input such as fluoroscopy / imaging position and X-ray irradiation conditions.

  The display control circuit 32 reads the dose distribution display program stored in the storage circuit 23 and develops it in the memory. The display control circuit 32 controls the area dose determination circuit 25, the dose distribution generation circuit 27, the display circuit 31, and the like according to the dose distribution display program developed in the memory. For example, the display control circuit 32 activates the area dose determination circuit 25 and the dose distribution generation circuit 27 to obtain a dose distribution including an X-ray irradiation field. The display control circuit 32 displays the X-ray irradiation field and dose distribution on the patient model on the display circuit 31 according to the X-ray irradiation state. The display mode concerning at least one of the information regarding the dose is changed and displayed.

  The control circuit 33 includes a CPU (Central Processing Unit) and a memory (not shown). The control circuit 33 temporarily stores information such as an operator's instruction and X-ray irradiation conditions such as imaging conditions and fluoroscopic conditions sent from the input interface circuit 29 in a memory (not shown). The control circuit 33 is configured to perform the X-ray imaging in accordance with the operator's instructions, fluoroscopy / imaging position, X-ray irradiation conditions, etc. stored in the memory, in order to execute the X-ray imaging. The limiter 11, the drive unit 17, and the like are controlled. The control circuit 33 performs the X-ray fluoroscopy according to the operator's instructions, fluoroscopy conditions, etc. stored in the memory, so that the high voltage generator 3, the X-ray detector 7, the irradiation range limiter 11, and the drive unit 17 Control etc.

  Next, the operation of the X-ray diagnostic apparatus configured as described above will be described with reference to the flowchart of FIG. 6 and the schematic diagrams of FIGS. In the following description, an operation for changing the display mode according to the state of the X-ray diagnostic apparatus 1 when generating and displaying the dose distribution of the subject P under X-ray fluoroscopy will be described.

  In the X-ray diagnostic apparatus 1, setting information such as the X-ray irradiation conditions and the X-ray detector to be used is input from the input interface circuit 29 to the control circuit 33 before the X-ray irradiation. The control circuit 33 can control the operation of the X-ray diagnostic apparatus 1 according to the setting information. In this state, the X-ray diagnostic apparatus 1 selects a patient model having a body shape close to the body shape of the subject P from the storage circuit 23 according to the operation of the operator, and causes the display circuit 31 to display the patient model. Further, the X-ray diagnostic apparatus 1 moves the support mechanism 9 and the top board 151 according to the operation of the operator, and the subject P placed on the top board 151 and the patient displayed on the display circuit 31. Perform alignment with the model. Subsequently, the X-ray diagnostic apparatus 1 starts X-ray fluoroscopy by irradiating the subject P with X-rays (step ST10). The control circuit 33 stores the X-ray irradiation condition, the geometric condition, and the irradiation area in the storage circuit 23 for each X-ray irradiation on the subject.

  The dose measuring device 13 measures the accumulated area dose of X-rays generated a plurality of times during the dose measurement period (step ST20), and stores the accumulated area dose read for each dose read cycle and the area dose determination circuit 25. Output to the circuit 23.

  The area dose determining circuit 25 determines a plurality of area doses (dose) respectively corresponding to a plurality of times of X-ray irradiation (generation) in the dose reading period based on the accumulated area dose and the X-ray irradiation conditions. The area dose determination circuit 25 outputs the determined plurality of area doses together with the corresponding irradiation area to the dose distribution generation circuit 27.

  The dose distribution generation circuit 27 generates a dose distribution including an X-ray irradiation field based on the position of the support mechanism 9, the position of the top plate 151, and the dose (step ST30). Note that the X-ray irradiation field corresponds to a region showing an increasing dose distribution in the dose distribution.

  The dose distribution generation circuit 27 adds the generated dose distribution to the dose distribution stored in the storage circuit 23. That is, the dose distribution for each X-ray irradiation is added. The added dose distribution is stored in the storage circuit 23.

  Subsequently, the display control circuit 32 causes the display circuit 31 to display the X-ray irradiation field and the dose distribution on the patient model Md according to the X-ray irradiation state (steps ST40 to ST50). Such a display control circuit 32 changes the display mode concerning at least one of the information about the X-ray trajectory or the X-ray dose to be irradiated, and causes the display circuit 31 to display the display mode. Specifically, for example, the display control circuit 32 determines whether or not the size of the X-ray irradiation field is smaller than a threshold value (step ST40). The size determination of the size of the X-ray irradiation field may be executed, for example, by determining the size of the irradiation area. When the irradiation area is small, the size of the irradiation field is also small. Alternatively, instead of determining the size of the irradiation field size, it may be determined whether or not the high-definition detector 72 (corresponding to a small irradiation field) is used. In the case of the MAF mode in which the high-definition detector 72 is used, the irradiation field is small. In any case, if the result of determination in step ST40 is that the X-ray irradiation field is small, the display control circuit 32 changes the display magnification ratio to a predetermined large value (step ST41). If the result of determination in step ST40 is no, the process proceeds to step ST50.

  Thereafter, the display control circuit 32 displays the dose distribution in the storage circuit 23 on the display circuit 31 together with the patient model (step ST50). In step ST50, when the display magnification is changed to a large value in step ST41, the display control circuit 32 enlarges and displays a screen including the X-ray irradiation field on the display circuit 31. The screen including the irradiation field displayed in an enlarged manner is a screen that displays the irradiation field and its surroundings among the screens that display the dose distribution together with the patient model Md.

  7 and 8 are schematic diagrams showing an example of a display screen in the display circuit 31, and FIG. 7 shows a screen when the enlargement ratio is not changed. FIG. 8 shows an enlargement ratio at step ST41. The screen when changing to a larger value is shown. In FIG. 7 and FIG. 8, the dose distribution is indicated by dots in the vicinity of the scapula of the patient model Md in the collapsed posture according to the size of the patient skin dose. Depending on the size, it is displayed in different hues. The same applies to the color bar arranged on the right side of the patient model Md and indicating the magnitude of the patient skin dose with dots and shades.

  In any case, when the display of the dose distribution in step ST50 is completed, if the X-ray fluoroscopy for the subject has not been completed (step ST51), the processes in steps ST20 to ST50 are repeatedly executed.

  After the step ST51, when the X-ray fluoroscopy is temporarily terminated between procedures, when the patient skin dose is large, the X-ray diagnostic apparatus 1 operates the input interface circuit 29 by the operator. Accordingly, the position of the support mechanism 9 or the position of the top plate 151 is moved. As a result, the X-ray irradiation field can be shifted to a region where the patient skin dose is small, so that local exposure that causes a locally high dose can be avoided. The same applies to the following embodiments.

  As described above, according to the first embodiment, the accumulated dose of X-rays generated a plurality of times within a predetermined period is measured, and X in the period is determined based on the accumulated dose and the X-ray irradiation conditions. Determine multiple doses, each corresponding to the generation of a line. Moreover, a dose distribution including an X-ray irradiation field is generated based on the X-ray irradiation conditions, the position of the support mechanism, the position of the bed, and the dose, and X-rays are generated on the patient model according to the X-ray irradiation state. Are displayed on the display unit (display circuit 31). At this time, the display mode concerning at least one of the information about the X-ray trajectory or the X-ray dose to be irradiated is changed and displayed. Therefore, the display can be easily recognized according to the irradiation state of the X-rays. In addition, since the display can be easily viewed, it is easy to visually recognize an increase in local dose, so that local exposure can be easily avoided.

  Further, when the size of the X-ray irradiation field is smaller than the threshold value, when displaying a screen including the X-ray irradiation field on the display unit (display circuit 31) in an enlarged manner, according to the irradiation situation that the irradiation field is small, The display can be easily recognized.

  Alternatively, among the first X-ray detector (X-ray detector 71) and the second X-ray detector (high-definition detector 72) having a higher spatial resolution than the first X-ray detector, When two X-ray detectors are used, the same effect can be obtained even if the screen including the X-ray irradiation field is enlarged and displayed on the display unit (display circuit 31).

<Second Embodiment>
Next, the X-ray diagnostic apparatus according to the second embodiment will be described with reference to FIG. 1, but the description of the overlapping parts will be omitted, and the different parts will be mainly described.

  The second embodiment is a modification of the first embodiment, and in order to make it easy to see according to the X-ray irradiation state, instead of the enlarged display of the irradiation field and its surrounding area, the X-ray trajectory. Alternatively, the dose rate is highlighted. Note that the X-ray irradiation status (in this embodiment, the dose is high) can be determined based on the X-ray irradiation conditions, the threshold corresponding to the type of procedure, or the MAF mode. Further, as the highlighting, a display with a changed color, a blinking display, or both can be used as appropriate.

  Accordingly, for example, the display control circuit 32 displays the X-ray trajectory or dose rate when the dose rate indicating the cumulative dose per unit time is higher than the threshold value instead of the above-described enlarged display function. To highlight. The dose rate is, for example, the cumulative dose per minute (mGy / min) by dividing the cumulative area dose (cumulative dose) measured by the dose meter 13 by the dose measurement period and adjusting the unit time as appropriate. Can be calculated as The calculation of the dose rate may be executed by either the dose meter 13 or the area dose determination circuit 25, for example. Further, instead of the configuration using the dose rate and the threshold value, the display control circuit 32 may cause the display circuit 31 to highlight the X-ray trajectory in the MAF mode.

  Alternatively, when using a dose rate and a threshold value, for example, as shown in FIG. 9, the type of procedure executed during X-ray irradiation and the threshold value are associated with each other and stored in advance in the storage circuit 23. Also good. In this case, the display control circuit 32 reads out the threshold value in the storage circuit 23 based on the type of procedure input by the input interface circuit 29, and compares the threshold value with the dose rate to thereby determine the dose rate. It is possible to obtain a comparison result indicating that is higher than the threshold value. The input interface circuit 29 constitutes an input unit for inputting the type of procedure before X-ray irradiation.

  Here, the type of procedure corresponds to, for example, the type used for IVR (interventional radiology). Examples of IVR include vascular IVR such as arterial embolization (TAE), percutaneous vasodilatation (PTA) and catheter ablation, and non-vascular IVR such as biopsy, abscess puncture drainage, and calculus removal. As a specific procedure type, for example, a required procedure may be set in advance among the procedures shown in the JJ1017 code. The threshold of the dose rate is set to a value that can avoid local exposure according to the type of procedure. For example, the threshold of the dose rate is set to a low value when it is related to a procedure that requires a long time even at a low dose compared to a normal procedure (eg, cardiac arrhythmia treatment).

  Other configurations are the same as those of the first embodiment.

  Next, the operation of the X-ray diagnostic apparatus configured as described above will be described using the flowchart of FIG. 10 and the schematic diagrams of FIGS. 11 and 12.

  Now, it is assumed that the processing from steps ST10 to ST30 is executed as described above, and the added dose distribution is stored in the storage circuit 23. However, in the present embodiment, the setting information input before X-ray irradiation may include the type of procedure.

  Subsequently, the display control circuit 32 executes steps ST42 to ST43 instead of the above-described steps ST40 to ST41. Thereby, the display control circuit 32 causes the display circuit 31 to display the X-ray irradiation field and the dose distribution on the patient model Md according to the X-ray irradiation state (steps ST42 to ST50). Such a display control circuit 32 changes the display mode concerning at least one of the information about the X-ray trajectory or the X-ray dose to be irradiated, and causes the display circuit 31 to display the display mode. Specifically, for example, the display control circuit 32 determines whether or not the dose rate indicating the cumulative dose per unit time is higher than a threshold value (step ST42). The determination of whether the dose rate is high or low may be made using a threshold set in advance for each type of procedure based on the type of procedure input before X-ray irradiation, and is in the MAF mode. You may determine using. In the case of the MAF mode, the dose rate is high corresponding to a high-quality X-ray image obtained using the high-definition detector 72. In any case, if the dose rate is high as a result of the determination in step ST42, the display control circuit 32 changes the display of the frame line of the X-ray locus or the background of the dose rate (step ST43). If the result of determination in step ST42 is no, the process proceeds to step ST50.

  Thereafter, the display control circuit 32 displays the dose distribution in the storage circuit 23 on the display circuit 31 together with the patient model (step ST50). In step ST50, when the display of the X-ray trajectory frame or the background of the dose rate is changed in step ST43, the display control circuit 32 highlights the X-ray trajectory frame or the dose rate. As the highlighting, a display with a changed color, a blinking display, or both are appropriately used.

  11 and 12 are schematic diagrams illustrating an example of a display screen in the display circuit 31. FIG. FIG. 11 shows a screen when the frame line L of the X-ray locus is highlighted with a bold line, and FIG. 12 shows a screen when the dose rate is highlighted by changing the background of the dose rate. When the dose rate is highlighted, either the background of the dose rate or the value of the dose rate may be highlighted, or both the background and value of the dose rate may be highlighted. In FIG. 11 and FIG. 12, the dose distribution is displayed in an enlarged manner, but the present invention is not limited to this and may not be displayed in an enlarged manner.

  In any case, when the display of the dose distribution in step ST50 is completed, if the X-ray fluoroscopy for the subject has not been completed (step ST51), the processes in steps ST20 to ST50 are repeatedly executed.

  As described above, according to the second embodiment, when the dose rate indicating the cumulative dose per unit time is higher than the threshold value, the X-ray trajectory or the dose rate is highlighted on the display unit (display circuit 31). . Thereby, it can display so that it may be easy to visually recognize that a dose rate is high. Here, the threshold value in the storage unit (storage circuit 23) is read based on the type of the input procedure, and the threshold value is compared with the dose rate, so that the dose rate is higher than the threshold value. The comparison result may be obtained. In this case, an appropriate threshold value can be used for determining the dose rate according to the type of procedure.

  When the second X-ray detector (high-definition detector 72) is used, when the X-ray trajectory is highlighted on the display unit (display circuit 31), the dose rate is calculated or the threshold value is set. While it is possible to omit the comparison and the like, similarly, it is possible to easily display that the dose rate is high.

Next, two modifications of the second embodiment will be described.
In the first modification, as shown in FIG. 13, the display is visually recognized according to the situation of the irradiation range limiter 11 such as ROI fluoroscopy using an ROI filter, compensation filter for preventing halation, and spot fluoroscopy using a diaphragm blade. It is the structure which makes it easy to do. In general, it is possible to highlight that the dose rate is high by processing such as making the frame of the X-ray trajectory into a double frame or changing the color of the surface of the patient model quickly according to the irradiation situation. it can. Hereinafter, each case of ROI fluoroscopy, compensation filter, and spot fluoroscopy will be described. However, the modifications regarding each of the ROI fluoroscopy, the compensation filter, and the spot fluoroscopy are not limited to being implemented separately, and any two or three of these may be implemented in combination with each other. Further, as the highlighting, a display with a changed color, a blinking display, or both are appropriately used.

  First, the case of ROI fluoroscopy will be described. When an ROI filter (region of interest filter) having an opening is inserted in the X-ray irradiation range, the display control circuit 32 has an X-ray locus frame Li corresponding to the opening and an X-ray locus corresponding to the irradiation field. At least a part of the double frame with the frame Lo is highlighted on the display circuit 31. For example, only the frame Li corresponding to the opening among the frames Li and Lo may be highlighted. The frame Li corresponding to the opening forms a substantially circular shape corresponding to the opening at a portion ri that intersects the surface of the patient model Md. The frame Lo corresponding to the irradiation field forms a square shape corresponding to the irradiation field narrowed by the diaphragm blades at a portion ro that intersects the surface of the patient model Md. These frames Li and Lo constitute a double frame in which the frame Li is positioned at a substantially central portion in the frame Lo. Further, since the dose inside the portion ri corresponding to the frame Li is higher than the outside of the frame Li, the color of the surface of the patient model Md changes faster than the outside of the frame Li.

  Next, the case of the compensation filter will be described. When the compensation filter forming the opening is inserted in the X-ray irradiation range, the display control circuit 32 highlights at least a part of the frame Lo of the X-ray trajectory corresponding to the irradiation field on the display circuit 31. A trajectory frame (not shown) corresponding to the opening forms a square shape corresponding to the opening at a portion ri that intersects the surface of the patient model Md. The frame Lo corresponding to the irradiation field forms a square shape corresponding to the irradiation field narrowed by the diaphragm blades at a portion ro that intersects the surface of the patient model Md. Even in the case of the compensation filter, as with the ROI filter, a double frame of a frame Lo of the X-ray locus corresponding to the irradiation field and a frame (not shown) of the locus corresponding to the opening is displayed. You may let them. Moreover, each part ri, ro comprises the double part in which the part ri is located in the approximate center part in the part ro. Further, since the dose inside the portion ri corresponding to the opening is higher than the outside of the portion ri, the surface color of the patient model Md changes faster than the outside of the portion ri.

  Next, the case of spot fluoroscopy will be described. The display control circuit 32 highlights at least a part of the frame Li of the X-ray trajectory corresponding to the opening on the display circuit 31 when the diaphragm blades forming the opening are inserted in the X-ray irradiation range. The frame Li forms a square shape corresponding to the opening at a portion ri that intersects the surface of the patient model Md. When the opening is widened, the portion where the frame Li and the surface of the patient model Md intersect is ro. In addition, the color of the surface of the patient model Md changes inside the portion ri corresponding to the opening according to the dose.

  Therefore, according to the first modification, when a region of interest filter (ROI filter) having an opening is inserted in the X-ray irradiation range, it corresponds to the X-ray trajectory frame and the irradiation field corresponding to the opening. At least a part of the double frame with the X-ray trajectory frame is highlighted on the display unit (display circuit 31). When a compensation filter that forms an opening is inserted in the X-ray irradiation range, at least a part of the X-ray trajectory frame corresponding to the irradiation field is highlighted on the display unit (display circuit 31). Further, when the diaphragm blades forming the opening are inserted in the X-ray irradiation range, at least one part of the X-ray trajectory frame corresponding to the opening is highlighted on the display unit (display circuit 31).

  Therefore, according to the first modification, when using the region-of-interest filter or the compensation filter, in addition to the effect of the second embodiment, the display can be more easily visually recognized according to the X-ray irradiation state. Can do. In addition, according to the first modification, when the aperture blade is used, the same effect as that of the second embodiment can be obtained.

  On the other hand, as shown in FIG. 14, the second modified example has a configuration in which the first and second embodiments are combined. As shown in the figure, after executing steps ST40 and ST41 in the first embodiment, steps ST42 and ST43 in the second embodiment are executed. Note that the second modified example is not limited thereto, and steps ST42 and ST43 may be executed before steps ST40 and ST41.

  In any case, according to the second modification, the effects of the first and second embodiments can be obtained by executing steps ST40 to ST43.

  According to at least one embodiment or one modification described above, the cumulative dose of X-rays generated a plurality of times within a predetermined period is measured, and based on the cumulative dose and the X-ray irradiation conditions, A plurality of doses respectively corresponding to the generation of X-rays in the period are determined. Moreover, a dose distribution including an X-ray irradiation field is generated based on the X-ray irradiation conditions, the position of the support mechanism, the position of the bed, and the dose, and X-rays are generated on the patient model according to the X-ray irradiation state. Are displayed on the display unit (display circuit 31). At this time, the display mode concerning at least one of the information about the X-ray trajectory or the X-ray dose to be irradiated is changed and displayed. Therefore, the display can be easily recognized according to the irradiation state of the X-rays.

  The term “processor” used in the above description is, for example, a central processing unit (CPU), a graphics processing unit (GPU), or an application specific integrated circuit (ASIC)), a programmable logic device (for example, It means a circuit such as a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA). 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. Furthermore, a plurality of components in FIG. 1 may be integrated into one processor to realize the function.

  The area dose determination circuit 25 in each embodiment is an example of a dose determination unit in the claims. The dose distribution generation circuit 27 in each embodiment is an example of a dose distribution generation unit in the claims. The display circuit 31 in each embodiment is an example of a display unit in the claims. The display control circuit 32 in each embodiment is an example of a display control unit in the claims. The X-ray detector 71 in each embodiment is an example of a first X-ray detector in the claims. The high-definition detector 72 in each embodiment is an example of a second X-ray detector in the claims. The storage circuit 23 in each embodiment is an example of a storage unit in the claims. The input interface circuit 29 in each embodiment is an example of an input unit in the claims.

  In addition, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof in the same manner as included in the scope and gist of the invention.

  DESCRIPTION OF SYMBOLS 1 ... X-ray diagnostic apparatus, 3 ... High voltage generation part, 5 ... X-ray tube, 7 ... X-ray detector, 71 ... X-ray detector, 72 ... High-definition detector, 9 ... Support mechanism, 11 ... Irradiation range Limiter, 13 ... Dosimeter, 15 ... Bed, 17 ... Drive unit, 19 ... Image generation circuit, 21 ... Communication interface circuit, 23 ... Memory circuit, 25 ... Area dose determination circuit, 27 ... Dose distribution generation circuit, 29 DESCRIPTION OF SYMBOLS ... Input interface circuit, 31 ... Display circuit, 32 ... Display control circuit, 33 ... Control circuit, 91 ... C arm, 93 ... Arm support part, 95 ... Arm holder, 151 ... Top plate.

Claims (8)

A support mechanism that movably supports an X-ray tube that generates X-rays that irradiate the subject and an X-ray detection device that detects X-rays transmitted through the subject;
A bed having a top plate on which the subject is placed;
A dose measuring unit for measuring a cumulative dose of the X-ray generated over a plurality of times within a predetermined period;
A dose determination unit that determines a plurality of doses respectively corresponding to the generation of the X-rays in the predetermined period based on the cumulative dose and the X-ray irradiation conditions;
A dose distribution generating unit that generates a dose distribution including the X-ray irradiation field based on the position of the support mechanism, the position of the bed, and the dose;
The display unit displays the X-ray irradiation field and the dose distribution on a patient model in accordance with the X-ray irradiation state, and at least one of the X-ray trajectory or the information on the X-ray dose to be irradiated An X-ray diagnostic apparatus comprising: a display control unit configured to display a display in a different manner.   The X-ray diagnosis according to claim 1, wherein the display control unit displays the X-ray trajectory or the dose rate on the display unit when a dose rate indicating a cumulative dose per unit time is higher than a threshold value. apparatus.   3. The display control unit according to claim 1, wherein when the size of the X-ray irradiation field is smaller than a threshold value, the display control unit enlarges and displays a screen including the X-ray irradiation field on the display unit. X-ray diagnostic equipment. The X-ray detection apparatus
A first X-ray detector for detecting X-rays transmitted through the subject;
A second X-ray detector that can be used by switching from the first X-ray detector, wherein the second X-ray detector has a higher spatial resolution than the first X-ray detector;
With
The X-ray diagnostic apparatus according to claim 1, wherein the display control unit highlights the locus of the X-rays on the display unit when the second X-ray detector is used. A storage unit that associates and stores the type of procedure performed during the X-ray irradiation and the threshold;
An input unit for inputting the type of the procedure before the X-ray irradiation;
With
The display control unit reads a threshold value in the storage unit based on the type of the input procedure, and compares the threshold value with the dose rate, whereby the dose rate is higher than the threshold value. The X-ray diagnostic apparatus according to claim 2, wherein a comparison result is obtained.   When the region-of-interest filter having an opening is inserted in the X-ray irradiation range, the display control unit includes an X-ray trajectory frame corresponding to the opening and an X-ray trajectory frame corresponding to the irradiation field. The X-ray diagnostic apparatus according to claim 2, wherein at least a part of a double frame is highlighted.   The display control unit highlights at least a part of an X-ray trajectory frame corresponding to the irradiation field when a compensation filter forming an opening is inserted in the X-ray irradiation range. X-ray diagnostic apparatus according to.   The display control unit highlights at least a part of a frame of an X-ray trajectory corresponding to the opening when a diaphragm blade forming an opening is inserted in the X-ray irradiation range. The X-ray diagnostic apparatus described.