JP7000025B2 - X-ray diagnostic device - Google Patents

Description

Embodiments of the present invention relate to an X-ray diagnostic apparatus.

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

Japanese Unexamined Patent Publication No. 2008-279117

However, the X-ray diagnostic apparatus as described above usually has no particular problem, 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 display of the irradiation field. Further, 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 irradiation condition of X-rays.

An object of the present invention is to provide an X-ray diagnostic apparatus capable of making the display easy to see according to the irradiation state of X-rays.

The X-ray diagnostic apparatus according to the embodiment includes a support mechanism, a sleeper, 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 to irradiate the subject and an X-ray detection device that detects the X-rays that have passed through the subject.

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

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

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

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 displays the X-ray irradiation field and the dose distribution on the patient model according to the X-ray irradiation status, and displays the X-ray trajectory or the X-ray to be irradiated. The display mode of at least one of the dose information 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 view showing the appearance of the X-ray diagnostic apparatus according to the same embodiment. FIG. 3 is a schematic diagram showing a dose readout cycle and the like in the same embodiment. FIG. 4 is a diagram showing 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 cumulative area dose in the same embodiment is divided into area doses. FIG. 6 is a flowchart for explaining the operation in the embodiment. FIG. 7 is a schematic diagram showing an example of a display screen in the same embodiment. FIG. 8 is a schematic diagram showing another example of the display screen in the same embodiment. FIG. 9 is a schematic diagram for explaining the setting information used for the 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 showing an example of a display screen in the same embodiment. FIG. 12 is a schematic diagram showing another example of the display screen in the same embodiment. FIG. 13 is a schematic diagram showing a display screen of a modified example of the same embodiment. FIG. 14 is a flowchart for explaining the operation of another modification of the same embodiment.

Hereinafter, each embodiment will be described with reference to the drawings, but before that, an outline of each embodiment will be described. The outline of each embodiment relates to an X-ray diagnostic apparatus that makes it easier to visually recognize the display according to the X-ray irradiation status for the dose distribution function that displays the dose distribution including the X-ray irradiation field during X-ray irradiation. .. Here, the first embodiment is an example of making it easier to see by enlarging the irradiation field and its surroundings according to the irradiation situation that the irradiation field is small. The second embodiment is an example of making it easier to see by highlighting the X-ray trajectory or the dose rate according to the irradiation situation 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 the configuration of the 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 detection device 7, a support mechanism 9, an irradiation range limiting device 11, a dose measuring device 13, and a top plate 151. The sleeper 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. , A display control circuit 32 and a control circuit 33. In FIG. 1, "I / F" is an abbreviation for "interface".

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

The high voltage generation unit 3 generates a tube current supplied to the X-ray tube 5 and a tube voltage applied to the X-ray tube 5. Under the control of the control circuit 33 described later, the high voltage generating unit 3 supplies a tube current suitable for X-ray photography and X-ray fluoroscopy to the X-ray tube 5 according to the X-ray irradiation conditions described later, and X-rays. A tube voltage suitable for radiography and X-ray fluoroscopy is applied to the X-ray tube 5.

For example, in the X-ray fluoroscopy to the subject P, the high voltage generation unit 3 applies the tube voltage to the X-ray tube 5 multiple times during the dose measurement period in the dose measuring device 13 described later, and applies the tube current to the X-ray tube 5. Supply to the X-ray tube 5. 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 during the dose measurement period is referred to as an irradiation time. Further, the interval of irradiating the subject P with X-rays in the dose measurement period is called an irradiation interval. The "subject" may be referred to as the "patient".

The X-ray tube 5 is based on the tube current supplied from the high voltage generating section 3 and the tube voltage applied by the high voltage generating section 3 from the focus of the X-ray (hereinafter referred to as the tube focus). Generates X-rays to irradiate subject P. The X-rays generated from the focal point of the tube are irradiated to the subject P through the X-ray emission window provided on the front surface of the X-ray tube 5.

The X-ray detector 7 is a planar X-ray detector 71 that converts X-rays transmitted through the subject P into charges and stores them, and X-rays with higher definition (higher resolution) than the X-ray detector 71. It has a high-definition detector 72 capable of detecting. In such an X-ray detector 7, for example, as shown in FIG. 2, the tip of the arm 97 has a high-definition detector 72, and the base end of the arm 97 is rotatable in the vicinity of the X-ray detector 71. Both detectors 71 and 72 may be switchable depending on the axially supported configuration. In this case, for example, the base end of the arm 97 arranges the high-definition detector 72 in front of the X-ray detector 71 in the mode in which the high-definition detector 72 is used, and high-definition in the mode in which the high-definition detector 72 is not used. It is controlled by a drive mechanism (not shown) so as to retract the detector 72. The mode in which the high-definition detector 72 is used 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 arranging minute semiconductor detection elements two-dimensionally in the column direction and the 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 an electric signal. The indirect conversion type is a type in which incident X-rays are converted into light by a phosphor and the light is converted into an electric signal.

The electric signals generated by the plurality of semiconductor detection elements due to the incident 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 the electrical signal into digital data. The A / D converter outputs digital data to a preprocessing unit (not shown). 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 switched from the X-ray detector 71 and can be used, and is an X-ray detector having a higher spatial resolution than the X-ray detector 71. For example, the high-definition detector 72 refers to a detector having a larger number of detection elements per unit area than the X-ray detector 71, and usually has four or more detection elements. Further, the high-definition detector 72 has a detection area of 4 to 6 inches smaller than that of 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, for example, a single crystal Si substrate. A CCD is a form of an image pickup device, and when X-rays are incident on a single crystal Si substrate, an electric charge is generated according to the incident X-ray dose. Further, the high-definition detector 72 may be configured by using a CMOS (Complementary metal-oxide-semiconductor) image sensor instead of the CCD. CMOS is also a form of an image pickup device, and like a CCD, when X-rays are incident on a single crystal Si substrate, an electric charge is generated according to the incident X-ray dose. Furthermore, in CMOS, the generated charge is stored as a capacitance, converted into a voltage component, and output.

The support mechanism 9 movably supports the X-ray tube 5 and the X-ray detector 7. Specifically, the support mechanism 9 has, 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 detector 7 so as to face each other. An Ω arm may be used instead of the C arm 91. The arm support portion 93 slidably supports the C arm 91 in a direction along the C shape of the C arm (hereinafter referred to as a first direction).

Further, the arm support portion 93 can rotate in a direction orthogonal to the first direction (hereinafter referred to as a second direction) with the arm holder 95 connecting the C arm 91 and the arm support portion 93 as a substantially center. Support 91. The arm support portion 93 can be moved in parallel in the short axis direction (X direction in FIGS. 1 and 2) and the long axis direction (Y direction in FIGS. 1 and 2) of the top plate 151 to be described later. It is also possible to support. Further, the C-arm 91 can change the distance between the tube focal point in the X-ray tube 5 and the X-ray detector 7 (the distance between the source image distances (hereinafter referred to as SID)), and the X-rays can be changed. It supports the tube 5 and the X-ray detector 7. Further, 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. Is the distance between the X-ray detector 71 and the X-ray detector 71.

The support mechanism 9 in the X-ray diagnostic apparatus 1 according to the present embodiment is not limited to the structure by the C arm 91. The support mechanism 9 may be movably supported in any direction by, for example, two arms (for example, a robot arm) that support the X-ray tube 5 and the X-ray detector 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 the over tube system and the under tube system, and can be applied to any form.

The irradiation range limiting device 11 is provided on the front surface of the X-ray emission window in the X-ray tube 5. That is, the irradiation range limiting device 11 is provided between the X-ray tube 5 and the X-ray detector 7 described later. The irradiation range limiting device 11 is also referred to as an X-ray movable diaphragm. Specifically, the irradiation range limiting device 11 has an irradiation range of the maximum diameter (hereinafter, maximum irradiation) so that the X-rays generated at the tube focal point are not unnecessarily exposed to radiation other than the imaging site desired by the operator. The 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 limiting device 11 limits the irradiation range by moving the diaphragm blades according to the irradiation range limiting instruction input by the input interface circuit 29 described later.

Specifically, the irradiation range limiting device 11 has 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 composed of lead that shields X-rays generated at the bulb focal point.

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

The radiation quality adjusting filter reduces, for example, low-energy X-ray components (soft-ray components) that are easily absorbed by the subject P among the X-rays generated at the focal point of the tube (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 the medical image generated by the 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 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 aperture region at least in part, eg, in the center, and attenuates X-rays outside the aperture region. Therefore, the ROI filter transmits all X-rays in the X-ray passing region of the opening region, and attenuates and transmits the X-rays in the other regions.

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

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

FIG. 3 is a diagram showing the dose reading cycle in the dose measuring instrument 13 together with the cumulative area dose read from the dose measuring instrument 13, the irradiation time, and the irradiation interval. Hereinafter, for the sake of simplicity, the number of times the subject P is irradiated with X-rays (hereinafter referred to as the number of times of irradiation) is set to 5 times in the dose readout cycle. The number of irradiations is not limited to 5, and may be any number of 2 or more.

The sleeper 15 has a top plate 151 (also referred to as a recumbent 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 sleeper 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 slides the C arm 91 in 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 arranged between the X-ray tube 5 and the X-ray detector 7. The drive unit 17 outputs the position of the X-ray tube 5 (or the position of the support mechanism 9) with respect to the top plate 151 to the dose distribution generation circuit 27 and the storage circuit 23, which will be 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, the drive unit 17 is in the short axis direction of the top plate 151 (X direction in FIGS. 1 and 2) or the long axis direction of the top plate 151 (FIG. 1, FIG. 2) based on the control signal from the control circuit 33. The top plate 151 is slid in the Y direction in FIG. 2). Further, the drive unit 17 moves up and down the top plate 151 in the vertical direction (Z direction in FIGS. 1 and 2). In addition, the drive unit 17 rotates the top plate 151 in order to tilt the top plate 151 with at least one of the major axis direction and the minor axis direction as the rotation axis (X-axis and Y-axis in FIG. 1). You may. The drive unit 17 outputs the position of the top plate 151 to the dose distribution generation circuit 27, which will be described later.

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

The preprocessing unit (not shown) executes preprocessing on the digital data output from the X-ray detector 71. The preprocessing includes correction of non-uniform sensitivity between channels in the X-ray detector 71, correction of extreme signal deterioration or data loss due to a strong X-ray absorber such as metal, and the like. The preprocessed digital data is output to the 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 that has been preprocessed after being X-ray fluoroscopic at a fluoroscopic position. Hereinafter, the photographed 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, which will be described later.

The communication interface circuit 21 is, for example, an interface for a network or an external storage device (not shown). The data such as the projected image and the analysis result obtained by the X-ray diagnostic apparatus 1 can be transferred to another apparatus via the communication interface circuit 21 and the network.

The storage circuit 23 is composed of 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 attached to the memory. Here, the storage circuit 23 includes various projected images generated by the image generation circuit 19, a control program of the X-ray diagnostic apparatus 1, a diagnostic protocol, and an operator's instruction sent from an input interface circuit 29 described later. It stores various data groups such as imaging conditions and fluoroscopic conditions, various data sent via the communication interface circuit 21 and the network, cumulative area dose, and the like. Further, the storage circuit 23 may store the relative positional relationship between the X-ray tube 5 and the top plate 151.

Specifically, the storage circuit 23 stores the X-ray irradiation conditions for each X-ray irradiation (generation) of the subject. The X-ray irradiation conditions include conditions related to radiation quality (tube voltage, tube current, etc.), irradiation time, irradiation interval, opening in the irradiation range limiting device 11, and the product of tube current (mA) and irradiation time (s) (hereinafter,). (Called tube current-time product (mAs)), the thickness of the quality-adjusting filter selected via the input interface circuit 29 (or the type of quality-adjusting filter), and the number of X-ray irradiations (generations) during the dose measurement period. , Field of view (FOV), irradiation rate (number of X-ray irradiations per second), and the like. The X-ray irradiation conditions are appropriately changed, for example, according to the thickness of the subject with respect to the imaging site. Among the X-ray irradiation conditions, the thickness (type), irradiation time, irradiation rate, etc. of the radiation quality adjusting filter are appropriately preset via the input interface circuit 29 described later.

The storage circuit 23 stores the geometrical conditions for each irradiation (generation) of X-rays to the subject. The geometric conditions include a predetermined reference position, a position of the top plate 151, a position of the C arm 91, an angle of the C arm 91, a SID, an 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 focal point. The storage circuit 23 may store a correspondence table of the irradiation area at the reference position with respect to the reference position and the aperture. Further, the storage circuit 23 stores the irradiation area for each X-ray irradiation.

The storage circuit 23 stores the patient model used in the dose distribution generation circuit 27 described later. The storage circuit 23 may store a dose distribution generation program that generates a dose distribution at a predetermined reference position. Further, 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 distribution in response to each of a plurality of X-ray generations (irradiations) over the dose measurement period, and X is stored for each dose measurement period. The line irradiation conditions, geometric conditions, and dose distribution may be updated and stored.

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

The area dose determination circuit 25 determines a plurality of area doses (dose) corresponding to each of a plurality of X-ray irradiations (generations) in the dose readout period based on the cumulative 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 cumulative area dose (for each dose measurement period). The area dose determination circuit 25 outputs the determined plurality of area doses to the dose distribution generation circuit 27 together with the corresponding irradiation areas.

Specifically, the area dose determination circuit 25 reads out the X-ray irradiation condition 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 determination circuit 25 determines the unit tube current time product and the dose per unit area (or the dose per unit area) based on the thickness of the radiation quality adjustment filter (or the type of the quality adjustment filter) and the tube voltage among the X-ray irradiation conditions. Hereinafter referred to as dose ratio K) is determined. Generally, tube voltage is not proportional to dose. Therefore, 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 (radio quality adjusting filters). Is. As shown in FIG. 4, the relationship between the tube voltage and the dose ratio K depends on the thickness of the quality adjusting filter inserted into the X-ray irradiation field by the irradiation range limiting device 11. That is, the thinner the thickness of the radiation quality adjusting filter, the larger the slope in the tube voltage-dose ratio relationship, as shown in FIG. Further, as the thickness of the radiation quality adjusting filter is thicker, as shown in FIG. 4, the slope in the tube voltage-dose ratio relationship becomes smaller. 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 into the X-ray irradiation field by the irradiation range limiting device 11.

The area dose determination circuit 25 determines the ratio of a plurality of area doses to the cumulative area dose (hereinafter referred to as area dose ratio (dose ratio)) based on the dose ratio, tube current time product, and irradiation area, as the dose measurement period. Determined 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 the area dose ratio by dividing each of the plurality of multiplication values relating to the irradiation (generation) of X-rays by the integrated value.

For example, in the dose measurement period, if the dose ratio K in the generation of the _i -th X-ray is Ki, the tube current time product is mAs _i , and the irradiation area S _i , the multiplication value in the generation of the i-th X-ray is K. It becomes _i × mAs _i × S _i . Further, assuming that the number of X-ray generations (irradiations) in the dose measurement period is n times, the integrated value and the area dose ratio are calculated as shown in the following equations, respectively.

Hereinafter, for the sake of simplicity, it is assumed that the number of X-rays generated (irradiated) during 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 the plurality of area dose ratios corresponding to the generations of the plurality of X-rays by the cumulative area dose. That is, the area dose corresponding to the generation of the i-th X-ray in the dose measurement period is determined by multiplying the area dose ratio of the above-mentioned formula by the cumulative area dose. From the above, the area dose determination circuit 25 can divide the cumulative area dose in the dose measurement period into the area dose for each generation (irradiation) of a plurality of X-rays in the dose measurement period.

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

When the imaging site is different for each X-ray irradiation, for example, as shown in FIG. 5, the area dose is different. The difference in the area dose for each X-ray irradiation is caused by, for example, the difference in the X-ray irradiation conditions due to the difference in the thickness of the subject for each imaging site. When the imaging site for each X-ray irradiation is the same, unlike FIG. 5, for example, the area dose for each X-ray irradiation is almost the same. Approximate equivalence of area doses is due, for example, to the fact that the X-ray irradiation conditions and the geometric conditions are approximately equal for each X-ray irradiation.

When the cumulative area dose is output for each dose measurement period, the area dose determination circuit 25 divides the output cumulative area dose into the area dose for each X-ray irradiation. The area dose determination circuit 25 outputs the area dose divided for each dose measurement period to the dose distribution generation circuit 27, which will be described later. The area dose determination circuit 25 may determine the area dose for each X-ray irradiation based on the irradiation history and the cumulative 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, the plurality of area doses, and the irradiation area. Specifically, the dose distribution generation circuit 27 generates a dose distribution based on a plurality of area doses, an irradiation area, a position of a support mechanism, and a 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 by 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. As a result, the dose distribution generation circuit 27 updates the dose distribution for each output of the cumulative area dose (for each dose measurement period). The dose distribution generation circuit 27 outputs the dose distribution to the display circuit 31 and the storage circuit 23, which will be described later.

Specifically, the dose distribution generation circuit 27 has an air kerma at a reference position based on the positional relationship (geometric condition) relative to the position of the support mechanism 9 and a plurality of area doses and irradiation areas. To 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 shape close to the body shape of the subject (patient) may be selectively read out. The body shape may be defined by, for example, a combination of a range of height and a range of weight. In this case, the patient model may be selected by the operator or may be selected by the dose distribution generation circuit 27 based on the height and weight of the subject. The "patient model" may be referred to as a "subject model". The dose distribution generation circuit 27 is based on the calculated air kerma, the irradiation area, the position of the support mechanism 9, and the relative positional relationship (geometric condition), and the dose at the irradiation position on the patient model (the dose (geometric condition)). Patient skin dose) is calculated.

The dose distribution generation circuit 27 can also calculate the patient skin dose in consideration of the influence of 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's skin dose to the irradiation position in the patient model.

The input interface circuit 29 inputs X-ray irradiation conditions such as X-ray imaging conditions and X-ray fluoroscopy conditions desired by the operator, fluoroscopy / imaging position, irradiation range, and the like according to the operation of the operator. .. Specifically, the input interface circuit 29 takes in various instructions, commands, information, selections, and settings from the operator into the X-ray diagnostic apparatus 1. The fluoroscopy / photographing position is defined by, for example, an angle with respect to the isocenter. For example, the origins of the first oblique direction (RAO), the second oblique direction (LAO), the caudal direction (CRA), and the caudal direction (CAU) are set as the fluoroscopic / photographing positions, and the origins of the three orthogonal axes in FIG. 2 are set. Assuming an isocenter, the angle of the perspective position at the starting point is 0 °.

The input interface circuit 29 integrates a trackball for setting an area of interest (ROI), a switch button, a mouse, a keyboard, a touch pad for performing input operations by touching an operation surface, and a display screen and a touch pad. It is realized by a 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 electric signal, and outputs the input operation to the display control circuit 32 or the control circuit 33. In the present specification, the input interface circuit 29 is not limited to the one provided with physical operating parts such as a mouse and a keyboard. For example, an input interface circuit is also an electric signal processing circuit that receives an electric signal corresponding to an input operation from an external input device provided separately from the device and outputs this electric signal to the display control circuit 32 or the control circuit 33. Included in 29 examples.

The display circuit 31 is composed of a plurality of displays for displaying medical images and the like, an internal circuit for supplying a display signal to each display, and peripheral circuits such as connectors and cables connecting each display and the internal circuit. .. The display circuit 31 displays the projected image generated by the image generation circuit 19 on one of the displays. 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 for inputting fluoroscopy / photographing position, X-ray irradiation conditions, and the like.

The display control circuit 32 reads out the dose distribution display program stored in the storage circuit 23 and expands 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. Further, the display control circuit 32 displays the X-ray irradiation field and the dose distribution on the patient model on the patient model according to the X-ray irradiation status, and displays the X-ray trajectory or the X-ray to be irradiated. The display mode of at least one of the dose information 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 sent from the input interface circuit 29 and X-ray irradiation conditions such as imaging conditions and fluoroscopic conditions in a memory (not shown). The control circuit 33 has a high voltage generation unit 3, an X-ray detection device 7, and an irradiation range in order to execute X-ray imaging according to an operator's instruction, a fluoroscopy / imaging position, an X-ray irradiation condition, etc. stored in the memory. It controls the limiter 11, the drive unit 17, and the like. The control circuit 33 has a high voltage generator 3, an X-ray detector 7, an irradiation range limiting device 11, and a drive unit 17 in order to execute X-ray fluoroscopy according to an operator's instruction, fluoroscopy conditions, etc. stored in the memory. And so on.

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 views of FIGS. 6 and 7. In the following description, an operation of generating a dose distribution of the subject P under fluoroscopy and changing the display mode depending on the state of the X-ray diagnostic apparatus 1 when displaying the dose distribution will be described.

The X-ray diagnostic apparatus 1 is operated by the operator to input setting information such as X-ray irradiation conditions and an X-ray detector to be used 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 displays the patient model on the display circuit 31. Further, the X-ray diagnostic apparatus 1 moves the support mechanism 9 and the top plate 151 according to the operation of the operator, and the subject P placed on the top plate 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 geometrical condition, and the irradiation area in the storage circuit 23 for each X-ray irradiation of the subject.

The dose measuring instrument 13 measures the cumulative area dose of X-rays generated multiple times during the dose measurement period (step ST20), and stores the cumulative area dose read out for each dose reading cycle in the area dose determination circuit 25 and the storage. Output to circuit 23.

The area dose determination circuit 25 determines a plurality of area doses (dose) corresponding to each of a plurality of X-ray irradiations (generations) in the dose readout period based on the cumulative area dose and the X-ray irradiation conditions. The area dose determination circuit 25 outputs the determined plurality of area doses to the dose distribution generation circuit 27 together with the corresponding irradiation areas.

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). The X-ray irradiation field corresponds to the region of the dose distribution showing the increasing 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 status (steps ST40 to ST50). Such a display control circuit 32 changes the display mode of at least one of the information regarding the trajectory of the X-ray or the dose of the X-ray to be irradiated, and causes the display circuit 31 to display the information. Specifically, for example, the display control circuit 32 determines whether or not the size of the X-ray irradiation field is smaller than the threshold value (step ST40). The size determination of the X-ray irradiation field may be performed by, for example, determining the size of the irradiation area. If the irradiation area is small, the size of the irradiation field is also small. Alternatively, instead of determining the size of the irradiation field, it may be determined whether or not the high-definition detector 72 (corresponding to the small irradiation field) is used. In the MAF mode in which the high-definition detector 72 is used, the irradiation field is small. In any case, if the X-ray irradiation field is small as a result of the determination in step ST40, the display control circuit 32 changes the enlargement ratio of the display to a predetermined large value (step ST41). If the result of the determination in step ST40 is no, the process proceeds to step ST50.

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

7 and 8 are schematic views showing an example of a display screen in the display circuit 31, FIG. 7 shows a screen when the enlargement ratio is not changed, and FIG. 8 shows an enlargement ratio in step ST41. Shows the screen when is changed to a large value. In FIGS. 7 and 8, the dose distribution is indicated by dots around the shoulder blade of the patient model Md in the prone position according to the magnitude of the patient's skin dose, but in reality, the magnitude of the patient's skin dose is large. It is displayed in different hues depending on the situation. This also applies to the color bar, which is placed on the right side of the patient model Md and indicates the magnitude of the patient's skin dose in dots and shades.

In any case, when the display of the dose distribution by step ST50 is completed, the processes of steps ST20 to ST50 are repeatedly executed unless the X-ray fluoroscopy for the subject is completed (step ST51).

If the patient's skin dose is large when fluoroscopy is temporarily terminated after step ST51, for example, during a procedure, the X-ray diagnostic apparatus 1 operates the input interface circuit 29 by the operator. The position of the support mechanism 9 or the position of the top plate 151 is moved according to the above. As a result, the X-ray irradiation field can be shifted to a region where the patient's skin dose is small, and thus local exposure to a locally high dose can be avoided. This also applies to each of the following embodiments.

As described above, according to the first embodiment, the cumulative dose of X-rays generated multiple times within a predetermined period is measured, and X-rays in the period are measured based on the cumulative dose and the X-ray irradiation conditions. Determine multiple doses corresponding to each line generation. In addition, a dose distribution including the 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 status. The irradiation field and the dose distribution of the above are displayed on the display unit (display circuit 31). At this time, the display mode of at least one of the information regarding the trajectory of the X-ray or the dose of the X-ray to be irradiated is changed and displayed. Therefore, the display can be easily visually recognized according to the X-ray irradiation status. In addition, by making the display easier to see, it becomes easier to visually recognize the 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 the screen including the X-ray irradiation field is enlarged and displayed on the display unit (display circuit 31), the irradiation field is small depending on the irradiation situation. The display can be made easy to see.

Alternatively, of 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, the first one. When the X-ray detector of No. 2 is 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 portion will be omitted, and the different portions will be mainly described.

The second embodiment is a modification of the first embodiment, and in order to make it easier to see according to the irradiation state of X-rays, the locus of X-rays is replaced with the enlarged display of the irradiation field and the surrounding area. Alternatively, the dose rate is highlighted. The X-ray irradiation state (a situation in which the dose is high in this embodiment) can be determined based on the X-ray irradiation condition, the threshold value according to the type of procedure, the MAF mode, and the like. Further, as the highlighting, a display in which the color is changed, a blinking display, or both of them can be appropriately used.

Along with this, for example, the display control circuit 32 displays the X-ray trajectory or the dose rate when the dose rate indicating the cumulative dose per unit time is higher than the threshold value instead of the enlarged display function described above. 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 measuring instrument 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 performed by, for example, either the dose measuring instrument 13 or the area dose determining circuit 25. Further, instead of the configuration using the dose rate and the threshold value, the display control circuit 32 may make the display circuit 31 highlight the X-ray locus in the case of the MAF mode.

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

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

Other configurations are the same as in the first embodiment.

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

Now, it is assumed that the processes from steps ST10 to ST30 are executed in the same manner 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 the irradiation of X-rays may include the type of procedure.

Subsequently, the display control circuit 32 executes steps ST42 to ST43 in place of the above-mentioned steps ST40 to ST41. As a result, 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 status (steps ST42 to ST50). Such a display control circuit 32 changes the display mode of at least one of the information regarding the trajectory of the X-ray or the dose of the X-ray to be irradiated, and causes the display circuit 31 to display the information. 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 the threshold value (step ST42). The high or low dose rate may be determined, for example, based on the type of procedure input before X-ray irradiation, using a threshold value set in advance for each type of procedure, and the MAF mode. May be determined using. In the MAF mode, the dose rate is high corresponding to the high-quality X-ray image obtained by 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 the determination in step ST42 is no, the process proceeds to step ST50.

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

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

In any case, when the display of the dose distribution by step ST50 is completed, the processes of steps ST20 to ST50 are repeatedly executed unless the X-ray fluoroscopy for the subject is completed (step ST51).

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). .. As a result, it is possible to display that the dose rate is high so that it can be easily visually recognized. Here, the threshold value in the storage unit (storage circuit 23) is read out based on the type of the input procedure, and the threshold value is compared with the dose rate to indicate that the dose rate is higher than the threshold value. You may try to obtain the comparison result of. In this case, an appropriate threshold value can be used for determining the dose rate according to the type of procedure.

Further, when the second X-ray detector (high-definition detector 72) is used and the X-ray locus is highlighted on the display unit (display circuit 31), the dose rate is calculated or the threshold value is used. While processing such as comparison can be omitted, it is also possible to easily visually indicate 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 limiting device 11 such as ROI fluoroscopy using an ROI filter, compensation filter for preventing halation, and spot fluoroscopy using diaphragm blades. It is configured to make it easy to do. Roughly speaking, it is possible to highlight the high dose rate by processing such as making the frame of the X-ray trajectory a double frame or changing the color of the surface of the patient model quickly according to the irradiation situation. can. Hereinafter, each case of ROI fluoroscopy, compensation filter, and spot fluoroscopy will be described. However, the modification for each of the ROI fluoroscopy, the compensation filter, and the spot fluoroscopy is not limited to the case where they are carried out separately, and any two or three of these may be carried out in combination with each other. Further, as the highlighting, a display in which the color is changed, a blinking display, or both of them is appropriately used.

First, the case of ROI fluoroscopy will be described. When the ROI filter (region of interest filter) having an aperture is inserted in the X-ray irradiation range, the display control circuit 32 has an X-ray trajectory frame Li corresponding to the aperture and an X-ray trajectory corresponding to the irradiation field. The display circuit 31 highlights at least one part of the double frame with the frame Lo. For example, of the frames Li and Lo, only the frame Li corresponding to the opening may be highlighted. The frame Li corresponding to the opening forms a substantially circular shape corresponding to the opening at the partial ri intersecting the surface of the patient model Md. The frame Lo corresponding to the irradiation field is a portion ro that intersects the surface of the patient model Md, and forms a square shape corresponding to the irradiation field narrowed by the diaphragm blades. These frames Li and Lo form a double frame in which the frame Li is located substantially in the center of the frame Lo. Further, since the dose inside the partial ri corresponding to the frame Li is higher than that outside 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 a compensation filter will be described. The display control circuit 32 causes the display circuit 31 to highlight at least one part of the frame Lo of the X-ray trajectory corresponding to the irradiation field when the compensation filter forming the aperture is inserted in the irradiation range of the X-ray. The locus frame (not shown) corresponding to the opening forms a square shape corresponding to the opening at the partial ri intersecting the surface of the patient model Md. The frame Lo corresponding to the irradiation field is a portion ro that intersects the surface of the patient model Md, and forms a square shape corresponding to the irradiation field narrowed by the diaphragm blades. Even in the case of the compensation filter, the double frame of the X-ray locus frame Lo corresponding to the irradiation field and the locus frame (not shown) corresponding to the opening is displayed as in the ROI filter. You may let me. Further, each partial ri and ro constitutes a double portion in which the partial ri is located in a substantially central portion within the partial ro. Further, since the dose on the inside of the partial ri corresponding to the opening is higher than that on the outside of the partial ri, the color of the surface of the patient model Md changes faster than the outside of the partial ri.

Next, the case of spot fluoroscopy will be described. When the diaphragm blade forming the opening is inserted in the irradiation range of the X-ray, the display control circuit 32 causes the display circuit 31 to highlight at least one part of the frame Li of the X-ray trajectory corresponding to the opening. The frame Li forms a square shape corresponding to the opening at the partial ri intersecting 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. Further, the color of the surface of the patient model Md changes according to the dose inside the partial ri corresponding to the opening.

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

Therefore, according to the first modification, when the region of interest filter or the compensation filter is used, in addition to the effect of the second embodiment, the display is made easier to be visually recognized depending on the X-ray irradiation condition. Can be done. Further, according to the first modification, when the diaphragm 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 modification has a configuration in which the first and second embodiments are combined. As shown in the figure, steps ST40 and ST41 in the first embodiment are executed, and then steps ST42 and ST43 in the second embodiment are executed. The second modification is not limited to this, 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 multiple times within a predetermined period is measured, and based on the cumulative dose and the X-ray irradiation conditions, Multiple doses corresponding to each X-ray outbreak during the period are determined. In addition, a dose distribution including the 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 status. The irradiation field and the dose distribution of the above are displayed on the display unit (display circuit 31). At this time, the display mode of at least one of the information regarding the trajectory of the X-ray or the dose of the X-ray to be irradiated is changed and displayed. Therefore, the display can be easily visually recognized according to the X-ray irradiation status.

The word "processor" used in the above description is, for example, a CPU (central processing unit), a GPU (Graphics Processing Unit), an integrated circuit for a specific application (Application Specific Integrated Circuit (ASIC)), or a programmable logic device (for example). , Simple Programmable Logic Device (SPLD), Complex Programmable Logic Device (CPLD), and Field Programmable Gate Array (FPGA)). 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, 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 within the scope of claims. The dose distribution generation circuit 27 in each embodiment is an example of a dose distribution generation unit within the scope of claims. The display circuit 31 in each embodiment is an example of a display unit within the scope of the claims. The display control circuit 32 in each embodiment is an example of a display control unit within the scope of the claims. The X-ray detector 71 in each embodiment is an example of the first X-ray detector in the claims. The high-definition detector 72 in each embodiment is an example of a second X-ray detector within the scope of claims. The storage circuit 23 in each embodiment is an example of a storage unit within the scope of claims. The input interface circuit 29 in each embodiment is an example of an input unit within the scope of claims.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope of the invention described in the claims and the equivalent scope thereof, as are included in the scope and gist of the invention.

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

Claims (2)

A support mechanism that movably supports an X-ray tube that generates X-rays to irradiate the subject and an X-ray detector that detects the X-rays that have passed through the subject.
A bed with a top plate on which the subject is placed, and
A dose measuring unit that measures the cumulative dose of X-rays generated multiple times within a predetermined period, and
A dose determination unit that determines a plurality of doses corresponding to the generation of X-rays in the predetermined period based on the cumulative dose and the X-ray irradiation condition.
A dose distribution generator 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 X-ray irradiation field and the dose distribution are displayed on the display unit on the patient model according to the X-ray irradiation status, and information on the frame line of the X-ray trajectory or the dose of the X-ray to be irradiated. A display control unit that changes the display mode of at least one of the above, and
A storage unit that stores the type of procedure performed during X-ray irradiation in association with the threshold value of the dose rate indicating the cumulative dose per unit time.
Before the X-ray irradiation, an input unit for inputting the type of the procedure and an input unit.
Equipped with
The irradiation situation includes the dose rate.
The frame line of the X-ray locus represents the outer edge of the X-ray locus from the X-ray tube to the subject.
The display control unit reads out the threshold value in the storage unit based on the type of the input procedure, and compares the threshold value with the dose rate so that the dose rate is higher than the threshold value. An X-ray diagnostic apparatus that highlights the frame line of the X-ray locus or the dose rate on the display unit when a comparison result to that effect is obtained. The irradiation situation includes the size of the irradiation field and
The X-ray diagnostic apparatus according to claim 1 , wherein the display control unit enlarges and displays a screen including the X-ray irradiation field on the display unit when the size of the X-ray irradiation field is smaller than the threshold value. ..

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