JP2018192237A - X-ray diagnostic apparatus - Google Patents

Abstract

To provide an X-ray diagnostic apparatus which displays an image of an ROI peripheral part in SPOT fluoroscopy.SOLUTION: An X-ray diagnostic apparatus 1 includes: an X-ray diaphragm device 15 which has an X-ray filter having a partial region or an opening region with larger transmittance of the X-ray than that of the other regions, and a diaphragm vane shielding the X-ray; a control unit which controls the X-ray diaphragm device so as to shield the X-ray passing through the opening region or the outside of the partial region of the X-ray filter at transition from the first fluoroscopy using the X-ray filter to the second fluoroscopy using the diaphragm vane for limiting an irradiation range; an image generation unit which generates first and second transparent images with the first and second fluoroscopy and generates a composite image obtained by compositing a non-region of an interest image corresponding to the irradiation region of the X-ray passing through the opening region or the outside of the partial region in the first transparent image and a region of the interest image corresponding to the irradiation region of the X-ray passing through the opening region or a partial region in the second transparent image; and a display control unit which displays the first transparent image on a display unit during the first fluoroscopy and displays the composite image on the display unit during the second fluoroscopy.SELECTED DRAWING: Figure 1

Description

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

  In an X-ray circulatory diagnosis apparatus, a fluoroscopy (hereinafter referred to as ROI) that provides a real-time image using an X-ray filter provided at the periphery of a region of interest (hereinafter referred to as ROI) as a function of dose reduction. Called fluoroscopy). In such fluoroscopy, when the degree of attenuation of the dose by the X-ray filter is 1/10 and the ratio of the ROI to the entire region of the X-ray irradiation range is 1/9, the X-ray dose by the ROI fluoroscopy is X This is reduced to 1/5 (= 1/9 × 1 + 1/9 × 1/10 × 8) as compared with the case where the entire region of the X-ray irradiation range is irradiated without a line filter. On the other hand, in the X-ray circulatory diagnosis apparatus, there is a fluoroscopy (hereinafter referred to as a SPOT fluoroscopy) that provides a real-time image by limiting the range corresponding to the non-interesting region with the diaphragm blades with respect to the entire X-ray irradiation range. is there.

  The X-ray dose by SPOT fluoroscopy is reduced to 1/9 (= 1/9 × 1 + 1/9 × 0), compared to the case of irradiating the entire region of the X-ray irradiation range without an X-ray filter. The In other words, the X-ray dose reduction by ROI fluoroscopy is about half the dose reduction compared to the X-ray dose reduction by SPOT fluoroscopy. The SPOT fluoroscopy has an advantage of dose reduction over the ROI fluoroscopy, but does not have image information on the periphery of the ROI.

JP 2007-159913 A Japanese Unexamined Patent Publication No. 2015-198783 JP 2006-288554 A JP-A-2005-27823 JP 2013-90912 A Japanese Patent Laid-Open No. 10-234714

  An object of the present invention is to provide an X-ray diagnostic apparatus capable of displaying an ROI peripheral image while performing dose reduction corresponding to SPOT fluoroscopy when performing SPOT fluoroscopy.

The X-ray diagnosis apparatus according to the present embodiment includes an X-ray detector, an X-ray diaphragm device, a control unit, an image generation unit, and a display control unit.
The X-ray detector faces the X-ray tube that generates X-rays and detects the X-rays.
The X-ray diaphragm apparatus includes an X-ray filter having a partial area or an opening area having a larger X-ray transmittance than other areas, and a diaphragm blade that blocks the X-ray.
The control unit is configured to change the opening region or the portion of the X-ray filter at the time of transition from the first fluoroscopy using the X-ray filter to the second fluoroscopy using the diaphragm blades in order to limit the irradiation range. The X-ray diaphragm device is controlled so as to shield the X-rays passing outside the region.
The image generation unit generates a first fluoroscopic image based on an output from the X-ray detector during execution of the first fluoroscopy, and outputs an output from the X-ray detector during execution of the second fluoroscopy. A second fluoroscopic image is generated based on the non-interested region image corresponding to the X-ray irradiation region that has passed outside the opening region or the partial region in the first fluoroscopic image during execution of the second fluoroscopy. Then, a synthesized image is generated by synthesizing the region-of-interest image corresponding to the X-ray irradiation region that has passed through the opening region or the partial region in the second fluoroscopic image.
The display control unit causes the display unit to display the first perspective image during execution of the first perspective, and causes the display unit to display the composite image during execution of the second perspective.

FIG. 1 is a configuration diagram showing the configuration of the X-ray diagnostic apparatus according to the present embodiment. FIG. 2 is a diagram illustrating an example of the configuration of the X-ray diaphragm apparatus according to the present embodiment. FIG. 3 is a view of the X-ray irradiation range viewed from the X-ray emission window side during execution of ROI fluoroscopy in the present embodiment. FIG. 4 is a view of the X-ray irradiation range viewed from the X-ray emission window side during execution of SPOT fluoroscopy in the present embodiment. FIG. 5 is a diagram illustrating an example of a composite image in the present embodiment. FIG. 6 is a flowchart illustrating an example of a processing procedure of the fluoroscopic function in the present embodiment. FIG. 7 is a view of the X-ray irradiation range viewed from the X-ray emission window side after the transition from SPOT fluoroscopy to ROI fluoroscopy in this embodiment. FIG. 8 is a diagram illustrating an example of the movement of the X-ray filter accompanying the movement of the position of the region of interest in the SPOT image and the movement of the diaphragm blades for shifting from the SPOT fluoroscopy to the ROI fluoroscopy in the present embodiment. FIG. 9 is a view of the X-ray irradiation range viewed from the X-ray emission window side during execution of SPOT fluoroscopy after the transition from ROI fluoroscopy after movement of the position of the region of interest to SPOT fluoroscopy in the present embodiment. FIG. 10 is a diagram illustrating an example of a region of interest, a marginal portion in the region of interest, and a non-region of interest in the second modification of the present embodiment. FIG. 11 shows an example of a region of interest in a composite image, a marginal portion in the region of interest, and a marginal portion adjacent to the marginal portion and included in the non-interesting region in the third modification of the present embodiment. FIG. FIG. 12 is a diagram illustrating a modification of the configuration related to the present embodiment. FIG. 13 is a diagram illustrating an example of a cross section of another X-ray filter in the present embodiment. FIG. 14 is a view of an X-ray irradiation range viewed from the X-ray emission window side during execution of ROI fluoroscopy in another X-ray filter according to the present embodiment.

  Hereinafter, an X-ray diagnostic apparatus according to an embodiment will be described with reference to the drawings. In the following description, components having substantially the same function and configuration are denoted by the same reference numerals, and redundant description will be given when necessary.

  FIG. 1 is a configuration diagram illustrating 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 11, an X-ray tube 13, an X-ray diaphragm device 15, an X-ray detector 17, a support frame 19, a bed (not shown) having a top plate 21, Image generation circuit (image generation unit) 23, communication interface circuit 25, input interface circuit (input unit) 27, control circuit (control unit) 29, storage circuit (storage unit) 31, and display circuit (display unit) 33).

  Note that the configuration of the X-ray diagnostic apparatus 1 according to the present embodiment may be configured as shown in FIG. FIG. 12 is a diagram illustrating a modification of the configuration related to the present embodiment. The X-ray diagnostic apparatus 1 includes a high voltage generator 11, an X-ray tube 13, an X-ray diaphragm device 15, an X-ray detector 17, a support frame 19, a bed (not shown) having a top plate 21, The communication interface circuit 25 includes an input interface circuit (input unit) 27, a processing circuit (processing unit) 30, a storage circuit (storage unit) 31, and a display circuit (display unit) 33. A processing circuit 30 in FIG. 12 is a circuit corresponding to the control circuit 29 in FIG. That is, the various processes and operations in the processing circuit 30 include various processes and operations related to the control circuit 29. For this reason, in the following description, the explanation about the processing circuit 30 can be understood by replacing “control circuit 29” with “processing circuit 30”. The image generation function (image generation unit) 301 in the processing circuit 30 has a function of executing various processes and operations executed in the image generation circuit 23 in FIG. Therefore, the explanation regarding the image generation function 301 can be understood by replacing “image generation circuit 23” with “image generation function 301 in the processing circuit 30”.

  The high voltage generator 11 generates a tube current supplied to the X-ray tube 13 and a tube voltage (high voltage) applied to the X-ray tube 13. Under the control of the control circuit 29, the high voltage generator 11 supplies tube currents suitable for X-ray imaging and X-ray fluoroscopy to the X-ray tube 13 in accordance with X-ray irradiation conditions described later. Under the control of the control circuit 29, the high voltage generator 11 applies tube voltages suitable for X-ray imaging and X-ray fluoroscopy to the X-ray tube 13 according to the X-ray irradiation conditions described later.

  The X-ray irradiation conditions are, for example, tube current, tube voltage, irradiation time, tube current (mA) and irradiation time (s) for each X-ray irradiation (hereinafter referred to as tube current time product (mAs)). Etc. The tube voltage applied by the high voltage generator 11 may be a method in which the tube voltage is applied to the X-ray tube 13 continuously in time, or a pulsed high voltage is applied to the X-ray tube 13 by high voltage switching. (Hereinafter, referred to as a high voltage pulse application method). Hereinafter, the high voltage generator 11 is demonstrated as what performs X-ray fluoroscopy using a high voltage pulse application system.

  The X-ray tube 13 is based on the tube current supplied from the high voltage generator 11 and the tube voltage applied by the high voltage generator 11 from the X-ray focus (hereinafter referred to as the tube focus). X-rays are generated. X-rays generated from the tube focus are irradiated onto the subject P in a state where X-rays in unnecessary areas are shielded by the X-ray diaphragm 15. The X-ray irradiation range 131 is indicated by a dotted line. The X-ray tube 13 in the present embodiment will be described as being a rotary anode type X-ray tube. The X-ray tube 13 in this embodiment may be another type of X-ray tube such as a fixed anode type X-ray tube. The X-ray tube 13 generates discrete pulse X-rays at a predetermined time interval with application of a pulsed high voltage by high voltage switching. A lead cone for blocking out-of-focus X-rays generated outside the tube focus is attached to the X-ray emission window of the X-ray tube 13.

  FIG. 2 is a diagram showing an example of the configuration of the X-ray diaphragm device 15 in the present embodiment. As shown in FIG. 2, the X-ray aperture device 15 includes an X-ray filter 151, an X-ray filter drive device 153 that drives the X-ray filter 151, an aperture blade 155, and an aperture blade drive device that drives the aperture blade 155. 157.

  The X-ray diaphragm device 15 is provided on the front surface of the X-ray tube 13 adjacent to the X-ray emission window 133 of the X-ray tube 13. The X-ray diaphragm device 15 limits the irradiation range of X-rays generated at the tube focal point 135. In addition to the X-ray filter 151, the X-ray diaphragm device 15 may have various filters (a quality control filter, an additional filter, a dose reduction filter, etc.). The relative positional relationship between the X-ray filter 151 and the diaphragm blade 155 is not limited to that shown in FIG. 2. For example, the X-ray filter 151 is disposed on the tube focus 135 side, and the diaphragm blade 155 is disposed on the top plate side. May be arranged.

  The X-ray filter 151 has an opening area, and reduces the dose of X-rays that pass outside the opening area. The X-ray filter 151 may be a filter that can change the size of the opening region in accordance with the size of the region of interest (ROI) of the subject P in the X-ray irradiation range 131.

  Note that the X-ray filter 151 may have a partial region having a higher X-ray transmittance than other regions, instead of the opening region. FIG. 13 is a diagram illustrating an example of a cross section of another X-ray filter different from the above-described X-ray filter having an opening region. As shown in FIG. 13, the X-ray filter 151 has a partial region 151PR having a higher X-ray transmittance than the other region 151OR. At this time, the X-ray filter 151 reduces the dose of X-rays that pass outside the partial region, that is, through the other region 151OR, as compared to the partial region 151PR. That is, the X-ray diaphragm device 15 according to the present embodiment includes an X-ray filter having a partial region or an opening region having a larger X-ray transmittance than other regions, and a diaphragm blade that blocks the X-rays.

  The X-ray filter driving device 153 drives the X-ray filter 151 under the control of the X-ray filter control function 291 in the control circuit 29. Specifically, the X-ray filter driving device 153 translates the X-ray filter 151 along the X and Y axes shown in FIG. 2 by the X-ray filter control function 291. Further, the X-ray filter driving device 153 translates the X-ray filter 151 along the Z axis shown in FIG. 2 by the X-ray filter control function 291 in accordance with the instruction to enlarge or reduce the region of interest via the input interface circuit 27. Moving. Note that the X-ray filter driving device 153 may change the size of the opening region in the X-ray filter 151 by the X-ray filter control function 291 in accordance with an instruction to enlarge or reduce the region of interest.

  The aperture blade 155 is constituted by a plurality of blades, for example, and shields X-rays. The diaphragm blade 155 prevents X-rays generated at the tube focal point 135 from being exposed unnecessarily to areas other than the imaging target region, in accordance with the irradiation area for irradiating the body surface of the subject P with X-rays. The irradiation range 131 is limited. The diaphragm blades 155 include, for example, a plurality of first diaphragm blades that can move in the X-axis direction and a plurality of second diaphragm blades that can move in the Y-axis direction. Each of the first and second diaphragm blades is made of lead that shields X-rays, for example. Each of the first and second diaphragm blades is moved in synchronization by a diaphragm blade driving device 157. The diaphragm blade 155 is not limited to a square diaphragm blade, and may be a polygonal diaphragm blade or a circular diaphragm blade.

  The diaphragm blade driving device 157 drives the diaphragm blade 155 by the diaphragm control function 293 in the control circuit 29. By driving the diaphragm blade 155, the X-ray irradiation range 131 is changed. For example, the diaphragm blade driving device 157 drives the diaphragm blade 155 to narrow the X-ray irradiation range 131 to the region of interest. Further, the diaphragm blade driving device 157 drives the diaphragm blade 155 in order to match the X-ray irradiation range 131 with the opening region or the partial region 151PR of the X-ray filter 151.

The X-ray detector 17 faces the X-ray tube 13 and detects X-rays generated from the X-ray tube 13. The X-ray detector 17 is configured by, for example, a flat panel detector (hereinafter referred to as FPD). The FPD has a plurality of semiconductor detection elements. Note that an image intensifier may be used as the X-ray detector 17. An electrical signal generated by a plurality of semiconductor detection elements with the incidence of X-rays is converted into an analog-to-digital converter (Analog to not shown).
(Digital converter: hereinafter referred to as A / D converter). The A / D converter converts an electrical signal into digital data. The A / D converter outputs digital data to the image generation circuit 23 or the processing circuit 30.

  The support frame 19 movably supports the X-ray tube 13 and the X-ray detector 17. Specifically, the support frame 19 is a C-arm. The C-arm mounts the X-ray tube 13 and the X-ray detector 17 so as to face each other. A support (not shown) supports the C arm in a direction along the C shape of the C arm (hereinafter referred to as a first direction) via a guide rail, a linear motion bearing, and the like so as to be slidable. The column is provided on the floor of the examination room. The support supports the C-arm via a bearing or the like so as to be rotatable in a direction orthogonal to the first direction (hereinafter referred to as the second direction). Note that the column can also support the C-arm through a bearing or the like so as to be able to translate in the short axis direction (X axis) and the long axis direction (Y axis) of the top plate 21. Further, the C arm can change the distance between the tube focal point 135 and the center of the X-ray detector 17 in the X-ray tube 13 (source image distance (hereinafter referred to as SID)). For example, the X-ray tube 13 and the X-ray detector 17 are supported via a guide rail and a linear motion bearing.

  As the support frame 19, an Ω arm may be used instead of the C arm. For example, two arms (for example, a robot arm or the like) that independently support the X-ray tube 13 and the X-ray detector 17 are used. May be used. Further, the support frame 19 may have a biplane structure including a C arm and an Ω arm.

  A couch not shown supports the top plate 21 (also referred to as a prone table) on which the subject P is placed so as to be movable. A subject P is placed on the top plate 21.

  A driving device (not shown) drives the support frame 19 and the bed, for example. The drive device includes, for example, a motor and a transmission mechanism (for example, a chain drive, a belt drive, a ball screw, etc.) that transmits a force generated by the motor to various units to be driven. The drive device slides the support frame 19 in the first direction and rotates it in the second direction in accordance with the drive signal corresponding to the control signal from the control circuit 29. During X-ray fluoroscopy and X-ray imaging, the subject P placed on the top 21 is disposed between the X-ray tube 13 and the X-ray detector 17. The drive device may rotate the X-ray detector 17 using the SID as a rotation axis under the control of the control circuit 29.

  The driving device moves the top plate 21 by driving the top plate 21 under the control of the control circuit 29. Specifically, the drive device is configured to provide bearings in the short axis direction (X axis direction) of the top plate 21 and the long axis direction (Y axis direction) of the top plate 21 based on a control signal from the control circuit 29. The top plate 21 is slid through a guide rail, a linear motion bearing or the like. Further, the drive device moves up and down the top plate 21 with respect to the vertical direction (Z-axis direction) via a bearing, a guide rail, a linear motion bearing, and the like. In addition, the drive device tilts the top plate 21 with at least one of the major axis direction and the minor axis direction as the rotation axis, and the top plate 21 is moved via a bearing, a guide rail, a linear motion bearing, or the like. You may rotate.

  The image generation circuit 23 (the image generation function 301 in the processing circuit 30) generates various images based on the output from the X-ray detector 17. The image generation circuit 23 outputs the generated various X-ray images to, for example, each circuit such as the control circuit 29, the storage circuit 31, and the display circuit 33. The image generation circuit 23 is realized by a processing circuit, and is, for example, a processor that reads various programs from the storage circuit 31 and executes them to perform various image processing corresponding to the read programs. In the above description, various functions related to image generation are executed in a single processing circuit. However, a processing circuit is configured by combining a plurality of independent processors, and each processor executes a program. Various functions may be realized by the above.

  The communication interface circuit 25 is a circuit having an interface function related to, for example, a network or an external storage device (not shown). Various image data obtained by the X-ray diagnostic apparatus 1 can be transferred to another apparatus via the communication interface circuit 25 and the network.

  The input interface circuit 27 takes in various instructions, commands, information, selections, and settings from the operator to the X-ray diagnostic apparatus 1. The input interface circuit 27 is realized by a switch button, a mouse, a keyboard, a touch pad that performs an input operation by touching an operation surface, and a touch panel display in which a display screen and a touch pad are integrated. The input interface circuit 27 converts an input operation received from the operator into an electrical signal. In the present specification, the input interface circuit 27 is not limited to the one having physical operation parts such as a mouse and a keyboard. For example, an electrical signal processing circuit that receives an electrical signal corresponding to an input operation from an external input device provided separately from the X-ray diagnostic apparatus 1 and outputs the received electrical signal to various circuits is also input. An example of the interface circuit 27 is included.

  Specifically, the input interface circuit 27 is used for an X-ray imaging condition such as an X-ray imaging condition and an X-ray fluoroscopic condition desired by the operator, a fluoroscopic / imaging position, an irradiation range, and a region of interest in the X-ray image. The position, size, etc. are input according to the operator's instructions. For example, the position of the region of interest is not limited to the central portion of the X-ray irradiation range 131 and can be set to any position such as a non-center position in the irradiation range.

  The control circuit (Controlling circuit) 29 includes a CPU (Central Processing Unit) and a memory (not shown). The control circuit 29 implements various functions by reading various programs for controlling various circuits, driving devices, and the like in the X-ray diagnostic apparatus 1 from the storage circuit 31 and executing the read programs. The control circuit 29 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 27 in a memory (not shown). The control circuit 29 is a high-voltage generator for performing X-ray imaging / X-ray fluoroscopy (pulse X-ray imaging) in accordance with an operator instruction, fluoroscopy / imaging position, X-ray irradiation conditions, etc. stored in the memory. 11. Controls the X-ray diaphragm device 15, the driving device, and the like.

  The control circuit 29 reads the filter control program related to the X-ray filter control function 291 from the storage circuit 31, and implements the X-ray filter control function 291 by executing the read filter control program. The X-ray filter control function 291 is a function for moving the X-ray filter 151 by controlling the X-ray filter driving device 153 in accordance with the movement of the region of interest and the change in the size of the region of interest.

  The control circuit 29 implements the aperture control function 293 by reading the aperture control program related to the aperture control function 293 from the storage circuit 31 and executing the read aperture control program. The diaphragm control function 293 is a diaphragm blade driving device 157 for adjusting the X-ray irradiation range 131 to the opening region or partial region 151PR of the X-ray filter 151 or opening the diaphragm blade 155 to the maximum X-ray irradiation range. This is a function of moving the aperture blade 155 by controlling the above.

  The control circuit 29 implements an automatic brightness adjustment function 295 by reading a program (hereinafter referred to as an ABC program) related to automatic brightness control (ABC) from the storage circuit 31 and executing the read ABC program. To do. Automatic brightness adjustment is a technique for obtaining appropriate brightness (hereinafter referred to as brightness level) in an X-ray image. For example, the automatic brightness adjustment is performed by changing the X-ray irradiation condition of the next frame so that the average value or the weighted average value of the pixel values in the region of interest in the X-ray image of a certain frame is brought close to the target range of the next frame. Thus, dynamic control is performed to keep the brightness level constant within the target range. Note that the target region for automatic brightness adjustment is not limited to the region of interest, and may be executed for the entire region of the X-ray image. The automatic brightness adjustment is performed, for example, when there is a moving fluoroscopic target part or a part where the transmitted dose greatly changes in the X-ray irradiation range 131. Also, the automatic brightness adjustment may not be executed when performing subtraction processing. At this time, the X-ray irradiation conditions remain fixed.

  The control circuit 29 reads the determination program related to the determination function 297 from the storage circuit 31 and executes the read determination program, thereby realizing the determination function 297. The determination function 297 refers to the first fluoroscopy (hereinafter referred to as ROI fluoroscopy) in which the aperture blade 155 is opened to the maximum X-ray irradiation range and the X-ray filter 151 is used to perform the X-ray irradiation range 131. Determination of the transition to the second fluoroscopy (hereinafter referred to as SPOT fluoroscopy) in which the blade 155 limits the X-ray filter 151 to the opening region or the partial region 151PR, and the transition from the SPOT fluoroscopy to the ROI fluoroscopy. The function to execute. The functions in this embodiment will be described in detail later.

  In the above description, it has been described that various functions are executed in the control circuit 29 by a single circuit. However, the control circuit 29 is configured by combining a plurality of independent processors, and each processor executes a program. As a result, various functions may be realized.

  In addition, the processors in the various circuits (each unit) of the present embodiment are not limited to being configured as a single circuit for each processor, but are configured as a single processor by combining a plurality of independent circuits, and various functions thereof May be realized. That is, various functions executed in the control circuit 29 may be executed by different processing circuits. Further, for example, the control circuit 29 and the image generation circuit 23 may be integrated into one processor (the processing circuit 30 shown in FIG. 12) to realize the function.

  The term “processor” used in the above description is, for example, a CPU (central processing unit), a GPU (graphics processing unit), an application specific integrated circuit (ASIC), a programmable logic device (for example, Circuits such as a simple programmable logic device (SPLD), a complex programmable logic device (Complex Programmable Logic Device: CPLD), and a field programmable gate array (FPGA) Meaning.

  The processor implements various functions by reading and executing a program stored in the storage circuit 31 described later. Instead of storing the program in the storage circuit 31, the program may be directly incorporated in the processor circuit. In this case, the processor implements various functions by reading and executing a program incorporated in the circuit.

  Each processor of the present embodiment is not limited to being configured as a single circuit for each processor, but is configured as a single processor by combining a plurality of independent circuits so as to realize various functions thereof. Also good. Further, a plurality of components in FIG. 1 may be integrated into one processor to realize the function.

  The storage circuit 31 includes various memories, HDD (hard disk drive), SSD (solid state drive), magnetic disk (floppy (registered trademark) disk, hard disk, etc.), optical disk (CD-ROM, DVD, etc.), semiconductor memory, and the like. Is done. The storage circuit 31 is executed in various X-ray images generated by the image generation circuit 23, a system control program of the X-ray diagnostic apparatus 1, various image generation programs executed in the image generation circuit 23, and the control circuit 29. A filter control program, an aperture control program, an ABC program, and a determination program are stored. The storage circuit 31 transmits a diagnostic protocol, an operator instruction sent from the input interface circuit 27, various data groups such as imaging conditions and fluoroscopic conditions related to X-ray imaging, and the communication interface circuit 25 and a network. It stores various data that are received.

  The display circuit 33 corresponds to a display device such as a display or a monitor. The display displays an X-ray image or a fluoroscopic image. The display displays a plurality of fluoroscopic images as moving images according to the frame rate of shooting in ROI fluoroscopy and SPOT fluoroscopy. The display displays an input screen related to input of fluoroscopy / imaging position, X-ray irradiation conditions, and the like.

  The above is the description of the overall configuration of the X-ray diagnostic apparatus 1 in the present embodiment. Next, details of the present embodiment will be described. The control circuit 29 in the X-ray diagnostic apparatus 1 according to the present embodiment performs X so as to shield X-rays that pass outside the opening area or outside the partial area 151PR of the X-ray filter 151 when shifting from ROI fluoroscopy to SPOT fluoroscopy. The line drawing device 15 is controlled. Depending on the positional relationship among the X-ray tube 13, the X-ray filter 151, and the diaphragm blade 155, the control circuit 29 may be located outside the opening area of the X-ray filter 151 or in the partial area 151 PR when shifting from ROI fluoroscopy to SPOT fluoroscopy. You may control the X-ray aperture apparatus 15 so that the X-ray which tries to pass outside, or the X-ray which passed can be shielded. For example, when the X-ray filter 151 is disposed on the front surface of the X-ray tube 13 and the diaphragm blade 155 is disposed on the front surface of the X-ray filter 151, the control circuit 29 is configured to switch from ROI fluoroscopy to SPOT fluoroscopy. The X-ray diaphragm unit 15 is controlled so as to shield X-rays that have passed outside the opening region or the partial region 151PR of the X-ray filter 151. When the diaphragm blade 155 is disposed on the front surface of the X-ray tube 13 and the X-ray filter 151 is disposed on the front surface of the diaphragm blade 155, the control circuit 29 is configured to change the X-ray filter from the ROI perspective to the SPOT perspective. The X-ray diaphragm device 15 is controlled so as to shield X-rays that try to pass outside the opening area of the line filter 151 or outside the partial area 151PR.

  3 and 14 are views of the X-ray irradiation range 131 viewed from the X-ray emission window 133 side during execution of ROI fluoroscopy. 3 and 14, the diaphragm blade 155 is not shown because it is opened to the maximum X-ray irradiation range during the ROI fluoroscopy. Although the opening region 152 of the X-ray filter 151 in FIG. 3 and the partial region 151PR in FIG. 14 are arranged in the central portion of the X-ray irradiation range 131, the present invention is not limited to this. That is, the opening region 152 and the partial region 151PR of the X-ray filter 151 are moved by the X-ray filter driving device 153 under the control of the X-ray filter control function 291 in the control circuit 29 according to the position of the region of interest. May be.

  FIG. 4 is a view of the X-ray irradiation range 131 viewed from the X-ray emission window 133 side during execution of SPOT fluoroscopy. In FIG. 4, the opening area 154 of the diaphragm blade 155 coincides with the opening area 152 and the partial area 151PR of the X-ray filter 151 during execution of the SPOT fluoroscopy. That is, at the time of transition from ROI fluoroscopy to SPOT fluoroscopy, the diaphragm blade 155 is moved between the aperture region 152 and the partial region 151PR of the X-ray filter 151 and the diaphragm blade 155 by the diaphragm blade driving device 157 controlled by the diaphragm control function 293. The X-ray irradiation range 131 is driven to narrow down so that the opening region 154 is aligned (arrow 156 in FIG. 4).

  The image generation circuit 23 generates a first fluoroscopic image (hereinafter referred to as an ROI fluoroscopic image) based on an output from the X-ray detector 17 during execution of ROI fluoroscopy. The image generation circuit 23 generates a second fluoroscopic image (hereinafter referred to as a SPOT fluoroscopic image) based on the output from the X-ray detector 17 during execution of the SPOT fluoroscopy. During execution of the SPOT fluoroscopy, the image generation circuit 23 is a non-interest area image (hereinafter referred to as a non-ROI image) corresponding to an X-ray irradiation area that has passed outside the opening area or the partial area 151PR in the ROI fluoroscopic image. And a region-of-interest image (hereinafter referred to as ROI image) corresponding to the X-ray irradiation region that has passed through the opening region or partial region 151PR in the SPOT fluoroscopic image is generated.

  FIG. 5 is a diagram illustrating an example of the composite image 231. A region 233 in FIG. 5 corresponds to a region of interest in the SPOT fluoroscopic image. A region 235 in FIG. 5 corresponds to a non-ROI image. As shown in FIG. 5, during execution of SPOT fluoroscopy, a composite image 231 obtained by synthesizing the ROI image obtained by SPOT fluoroscopy and the non-ROI image obtained by ROI fluoroscopy is displayed on the display.

  FIG. 6 is a flowchart illustrating an example of a processing procedure of the fluoroscopic function in the present embodiment. In the following description of the flowchart, it is assumed that an X-ray filter 151 having an opening region 152 is used as shown in FIG. When the X-ray filter 151 having a partial region is used, it will be understood by replacing “the opening region 152 of the X-ray filter 151” with “the partial region 151PR of the X-ray filter 151” in the following description.

(Step Sa1)
A region of interest is set according to an instruction from the operator via the input interface circuit 27. The control circuit 29 controls the X-ray filter driving device 153 with the X-ray filter control function 291 in order to align the opening region 152 of the X-ray filter 151 with the set region of interest prior to execution of ROI fluoroscopy. The X-ray filter driving device 153 moves the X-ray filter 151 by the X-ray filter control function 291. Thereby, the opening area 152 of the X-ray filter 151 coincides with the region of interest. Next, the control circuit 29 performs ROI fluoroscopy according to predetermined fluoroscopic conditions. The image generation circuit 23 generates an ROI fluoroscopic image based on the output from the X-ray detector 17. The processing circuit 30 causes the display control function 303 to display the ROI fluoroscopic image on the display during execution of the ROI fluoroscopy. The display circuit 33 displays the ROI fluoroscopic image. The display control function 303 is an example of a display control unit.

  When the ROI fluoroscopy is repeated, the ROI fluoroscopy image is displayed as a moving image by being updated according to the generation of pulse X-rays. Note that ROI fluoroscopy may be executed by one pulse X-ray. At this time, one ROI fluoroscopic image is displayed. Further, the automatic brightness adjustment function 295 may be executed in the ROI fluoroscopy. At this time, the control circuit 29 uses the automatic brightness adjustment function 295 to keep the brightness level constant over a predetermined time within the target range in the entire region of the ROI fluoroscopic image or a partial region such as the region of interest, that is, the automatic brightness. Until the brightness value in the ROI fluoroscopic image is settled by the adjustment, the ROI fluoroscopy is repeatedly executed while changing the fluoroscopic conditions. Note that the predetermined time is not only set at the stage until the installation of the device, but is also set / changed by the user during use, or automatically set / changed based on the operation history of the user. May be. That is, the predetermined time may be set before the fluoroscopic function in the present embodiment is executed.

(Step Sa2)
The image generation circuit 23 generates a non-ROI image based on the ROI fluoroscopic image. Specifically, the image generation circuit 23 uses the X-ray filter 151 to compare the contrast of a plurality of pixel values corresponding to the X-ray irradiation area (non-interest area) that has passed outside the opening area in the ROI fluoroscopic image. A non-ROI image is generated by compensating in accordance with the reduction of the X-ray dose (hereinafter referred to as dose compensation processing). The dose compensation processing is, for example, processing that compensates for a pixel value difference between fluoroscopy using the X-ray filter 151 and fluoroscopy using the X-ray filter 151 to a pixel value in fluoroscopy using the X-ray filter 151.

  When a plurality of ROI fluoroscopic images are generated by ROI fluoroscopy, the image generation circuit 23 adds the pixel values of the plurality of ROI fluoroscopic images using temporal filters such as a recursive filter for pixels at the same position. Later, non-ROI images may be generated by averaging and performing dose compensation processing on the averaged pixel values. When the fluoroscopic target part is an organ that operates in a predetermined cycle (heartbeat) such as the heart, for example, a series of ROI fluoroscopic images along a time series is obtained by performing ROI fluoroscopy over a predetermined cycle. Generated. At this time, the non-ROI image is temporarily stored in the storage circuit 31 or the like in association with a time phase in a predetermined cycle (for example, a cardiac phase in an electrocardiographic waveform).

  When automatic brightness adjustment is performed for ROI fluoroscopy, the image generation circuit 23 performs, for example, dose compensation processing based on the ROI fluoroscopy image corresponding to the ROI fluoroscopy performed according to the last changed fluoroscopy condition. To generate a non-ROI image. The non-ROI image is temporarily stored in the storage circuit 31 or the like.

(Step Sa3)
Based on the determination result by the determination function 297, the control circuit 29 shifts from ROI fluoroscopy to SPOT fluoroscopy, and executes SPOT fluoroscopy. Specifically, the control circuit 29 uses an aperture control function 293 that shields X-rays outside the opening area (non-interest area) in a transition period from ROI fluoroscopy to SPOT fluoroscopy at a predetermined timing. The diaphragm device 15 is controlled. The description of the control of the X-ray diaphragm device 15 during the transition period from ROI fluoroscopy to SPOT fluoroscopy overlaps with the above description using the filter of FIG. The predetermined timing is, for example, when one ROI fluoroscopic image is generated in ROI fluoroscopy, when a plurality of ROI fluoroscopic images are generated, or when automatic brightness adjustment is completed. That is, the control circuit 29 controls the X-ray diaphragm device 15 in response to generation of one ROI fluoroscopic image, generation of a plurality of ROI fluoroscopic images, or completion of automatic brightness adjustment during execution of ROI fluoroscopy. .

  When the X-ray irradiation range is narrowed down so that the opening region 152 of the X-ray filter 151 and the opening region 154 of the diaphragm blade 155 are aligned, the control circuit 29 performs SPOT fluoroscopy. The control circuit 29 controls the high voltage generator 11 so as to stop the application of the high voltage to the X-ray tube 13 during the operation period of the diaphragm blade 155 at the time of transition from ROI fluoroscopy to SPOT fluoroscopy. Also good. At this time, the control circuit 29 may control the display circuit 33 so as to continuously display the ROI fluoroscopic image (first fluoroscopic image) acquired in the immediately preceding ROI fluoroscopic (first fluoroscopic). The image generation circuit 23 generates a SPOT fluoroscopic image based on the output from the X-ray detector 17.

(Step Sa4)
The image generation circuit 23 extracts an ROI image from the SPOT fluoroscopic image. The image generation circuit 23 generates a composite image 231 by combining the non-ROI image and the ROI image in position alignment. When the fluoroscopic target site is an organ that operates in a predetermined cycle (heartbeat) such as the heart, the image generation circuit 23 adds time phase information such as a cardiac phase based on an electrocardiographic waveform to the ROI image. At this time, the image generation circuit 23 generates a synthesized image 231 in time series by synthesizing the ROI image and the non-ROI image having substantially the same cardiac phase in position alignment. The processing circuit 30 causes the display control function 303 to display the composite image on the display during execution of the SPOT fluoroscopy. The display circuit 33 displays the composite image 231 during the SPOT fluoroscopy.

(Step Sa5)
When the SPOT fluoroscopic end instruction is input via the input interface circuit 27 (Yes in step Sa5), the processing of the fluoroscopic function according to the present embodiment ends. When the SPOT fluoroscopy end instruction is not input via the input interface circuit 27 (No in step Sa5), the process proceeds to step Sa6.

(Step Sa6)
The control circuit 29 uses the determination function 297 to determine whether switching from SPOT fluoroscopy to ROI fluoroscopy is performed. Specifically, the control circuit 29 moves the top plate 21, moves the support frame 19, moves the position of the region of interest in the SPOT image, and changes the size of the region of interest during execution of the SPOT fluoroscopy. In response to the execution of at least one of enlargement or reduction of the region of interest (Yes in step Sa6), the aperture control function 293 controls the X-ray aperture device 15 so as to shift from the SPOT fluoroscopy to the ROI fluoroscopy. When the control circuit 29 receives an execution instruction of ROI fluoroscopy in response to an operator instruction via the input interface circuit 27 during execution of the SPOT fluoroscopy, the control circuit 29 shifts from the SPOT fluoroscopy to the ROI fluoroscopy. 15 may be controlled.

  In determining whether or not switching from SPOT fluoroscopy to ROI fluoroscopy is performed, the amount of movement of the top 21, the amount of movement of the support frame 19, the amount of movement of the region of interest in the SPOT image, and the size of the region of interest A plurality of predetermined threshold values respectively corresponding to the change amount and the amount of enlargement or reduction of the region of interest may be used. For example, during execution of SPOT fluoroscopy, the control circuit 29 or the processing circuit 30 uses the determination function 297 to compare the above amounts with respective predetermined threshold values. When at least one of the above amounts exceeds a corresponding threshold value, the control circuit 29 or the processing circuit 30 controls the X-ray diaphragm device 15 by the diaphragm control function 293 so as to shift from SPOT fluoroscopy to ROI fluoroscopy. That is, when the amount does not exceed the corresponding threshold during execution of the SPOT fluoroscopy, switching from the SPOT fluoroscopy to the ROI fluoroscopy can be suppressed. In other words, robustness related to switching from SPOT fluoroscopy to ROI fluoroscopy can be improved. Note that the predetermined threshold value is not only set at the stage until the installation of the apparatus, but also set / changed during use by the user, or automatically set / changed based on the operation history of the user. May be. That is, the predetermined threshold value includes the movement of the top plate 21, the movement of the support frame 19, the movement of the position of the region of interest in the SPOT image, the change of the size of the region of interest, and the enlargement or reduction of the region of interest. It suffices if it is set by the time of determining whether or not at least one of them has been implemented (step Sa6).

  The region of interest is enlarged by bringing at least one of the X-ray tube 13 and the X-ray detector 17 closer to the subject P, that is, by shortening the SID, so that the region of the subject P that is relatively included in the region of interest. It corresponds to enlarging the size. Note that the region of interest may be expanded by expanding the region of interest in the composite image 231. The region of interest is reduced by moving at least one of the X-ray tube 13 and the X-ray detector 17 away from the subject P, that is, by increasing the length of the SID, thereby relatively increasing the size of the portion of the subject P included in the region of interest. This corresponds to reducing the size. Note that the reduction of the region of interest may be reduction of the region of interest in the composite image 231.

  Specifically, the control circuit 29 uses the X-ray filter control function 291 to drive the X-ray filter in order to align the opening region 152 of the X-ray filter 151 with the position of the region of interest input prior to performing the ROI fluoroscopy. The device 153 is controlled. For example, as shown in FIG. 4, the X-ray filter drive device 153 moves the X-ray filter 151 under the control of the control circuit 29. Thereby, the opening area 152 of the X-ray filter 151 coincides with the region of interest. The control circuit 29 controls the high voltage generator 11 so as to stop the application of the high voltage to the X-ray tube 13 during the operation period of the diaphragm blade 155 at the time of transition from SPOT fluoroscopy to ROI fluoroscopy. Also good. At this time, the control circuit 29 may control the display circuit 33 so as to continuously display the SPOT fluoroscopic image (second fluoroscopic image) acquired in the immediately preceding SPOT fluoroscopy (second fluoroscopy).

  FIG. 7 is a view of the X-ray irradiation range after the transition from SPOT fluoroscopy to ROI fluoroscopy as seen from the X-ray emission window 133 side. In FIG. 7, the aperture blade 155 is opened to the maximum X-ray irradiation range in ROI fluoroscopy. That is, at the time of transition from SPOT fluoroscopy to ROI fluoroscopy, the diaphragm blades 155 are opened to the maximum X-ray irradiation range by the diaphragm blade driving device 157 (arrow 158 in FIG. 7). Thereby, the ROI fluoroscopic image is generated by irradiating the non-interest region with X-rays. A non-ROI image is generated based on the ROI fluoroscopic image.

  FIG. 8 is a diagram illustrating an example of the movement of the X-ray filter 151 accompanying the movement of the position of the region of interest in the SPOT image and the movement of the diaphragm blade 155 for shifting from the SPOT fluoroscopy to the ROI fluoroscopy. A dotted line 1521 in FIG. 8 indicates the opening region 152 of the X-ray filter 151 before the position of the region of interest is moved. As the position of the region of interest moves, the X-ray filter 151 is moved by the X-ray filter driving device 153 under the control of the X-ray filter control function 291 (arrow 1523 in FIG. 8). Along with the movement of the X-ray filter 151, the diaphragm blade 155 is opened to the maximum X-ray irradiation range by the diaphragm blade driving device 157 under the control of the diaphragm control function 293 (arrow 159 in FIG. 8).

  FIG. 9 is a view of the X-ray irradiation range 131 during execution of the SPOT fluoroscopy after the transition from the ROI fluoroscopy after the movement of the region of interest to the SPOT fluoroscopy is viewed from the X-ray emission window 133 side. In FIG. 9, the opening area 154 of the diaphragm blade 155 coincides with the opening area 152 of the X-ray filter 151 during execution of the SPOT fluoroscopy. In other words, at the time of transition from ROI fluoroscopy to SPOT fluoroscopy, the diaphragm blade 155 is moved between the aperture region 152 of the X-ray filter 151 and the aperture region 154 of the diaphragm blade 155 by the diaphragm blade drive device 157 controlled by the diaphragm control function 293. The X-ray irradiation range 131 is narrowed so as to match (arrow 160 in FIG. 9).

  During execution of the SPOT fluoroscopy, the control circuit 29 moves the top plate 21, moves the support frame 19, moves the position of the region of interest in the SPOT image, changes the size of the region of interest, and enlarges the region of interest. Alternatively, if all the reduction is not performed, the SPOT fluoroscopy is continued (No in step Sa6).

(Step Sa7)
The control circuit 29 performs ROI fluoroscopy. The image generation circuit 23 generates an ROI fluoroscopic image based on the output from the X-ray detector 17. The display circuit 33 displays the ROI fluoroscopic image. Since the processing in this step is substantially the same as that in step Sa1, detailed description is omitted.

(Step Sa8)
The image generation circuit 23 generates a non-ROI image based on the ROI fluoroscopic image. Since the processing in this step is substantially the same as that in step Sa2, detailed description thereof is omitted. The non-ROI image is updated and temporarily stored in the storage circuit 31 or the like.

(Step Sa9)
The control circuit 29 uses the determination function 297 to determine whether or not switching from ROI fluoroscopy to SPOT fluoroscopy is performed. Specifically, the control circuit 29 moves the top plate 21, moves the support frame 19, moves the position of the region of interest in the SPOT image, and changes the size of the region of interest during execution of the SPOT fluoroscopy. When at least one of enlargement or reduction of the region of interest is further executed, the ROI fluoroscopy is continued (No in step Sa9). The control circuit 29 shifts from ROI fluoroscopy to SPOT fluoroscopy at a predetermined timing (Yes in step Sa9), and executes the SPOT fluoroscopy. Since the above contents are described in step Sa3, detailed description is omitted.

  Further, during execution of ROI fluoroscopy after transition from SPOT fluoroscopy to ROI fluoroscopy, the movement of the top plate 21, the movement of the support frame 19, the movement of the position of the region of interest, the change of the size of the region of interest, If enlargement or reduction of the region of interest is not executed, the control circuit 29 controls the X-ray iris device 15 by the iris control function 293 so as to shift from the ROI fluoroscopy performed again to the SPOT fluoroscopy (in step Sa9). YES) Note that the control of the X-ray diaphragm 15 for shifting from the ROI fluoroscopy performed again to the SPOT fluoroscopy may be performed in consideration of a predetermined timing as described in step Sa3.

According to the configuration described above, the following effects can be obtained.
According to the X-ray diagnostic apparatus 1 in the present embodiment, the X-ray diaphragm apparatus 15 shields X-rays that pass outside the opening area or the partial area of the X-ray filter 151 when shifting from ROI fluoroscopy to SPOT fluoroscopy. During the execution of the SPOT fluoroscopy, the non-ROI image corresponding to the X-ray irradiation area that has passed outside the open area or the partial area in the ROI fluoroscopic image, and the open area or the partial area in the SPOT fluoroscopic image It is possible to generate a composite image 231 by combining the ROI image corresponding to the X-ray irradiation region that has passed, display the ROI fluoroscopic image during execution of ROI fluoroscopy, and display the composite image 231 during execution of SPOT fluoroscopy. it can. Thereby, by using both ROI fluoroscopy and SPOT fluoroscopy, it is possible to display an image of the peripheral part (non-interesting region) of the region of interest in the SPOT fluoroscopy while realizing dose reduction close to SPOT fluoroscopy.

  In addition, according to the present embodiment, the X-ray filter 151 is used to compare the contrast of a plurality of pixel values corresponding to the X-ray irradiation region that has passed outside the opening region or the partial region in the ROI fluoroscopic image by the dose compensation processing. A non-ROI image can be generated by compensating according to the reduction of the X-ray dose (transmittance). Accordingly, since the contrast of the non-interest region in the composite image 231 can be made closer to the contrast of the region of interest in the composite image 231, the composite image 231 in which the visibility of the boundary between the region of interest and the non-interest region is reduced is displayed. can do.

  In addition, according to the present embodiment, the X-ray diaphragm device 15 can be controlled so as to shift from ROI fluoroscopy to SPOT fluoroscopy in response to the generation of one ROI fluoroscopic image during execution of ROI fluoroscopy. Thereby, the execution time of ROI fluoroscopy can be shortened, and the exposure dose with respect to the non-interest area | region in the subject P can be reduced.

  In addition, according to the present embodiment, the X-ray diaphragm device 15 is controlled so as to shift from ROI fluoroscopy to SPOT fluoroscopy when a plurality of ROI fluoroscopy images are generated during execution of ROI fluoroscopy. A non-ROI image can be generated by averaging the pixel values of the ROI fluoroscopic image at pixels at the same position. Thereby, noise in the non-ROI image can be reduced, and a high-quality composite image 231 can be displayed.

  Further, according to the present embodiment, the transition from ROI fluoroscopy to SPOT fluoroscopy is triggered by the fact that the brightness level of the ROI fluoroscopy image becomes constant over a predetermined time within the target range during execution of ROI fluoroscopy. Thus, the X-ray diaphragm device 15 can be controlled and the ROI fluoroscopic image acquired in the immediately preceding ROI fluoroscopic can be continuously displayed. Thereby, ROI fluoroscopy and SPOT fluoroscopy can be executed under optimal fluoroscopy conditions for displaying the ROI fluoroscopy image and the composite image 231, and the ROI fluoroscopy image and the composite image 231 can be displayed at an optimal luminance level.

  Further, according to the present embodiment, the high voltage applied to the X-ray tube 13 during the operation period of the aperture blade 155 in at least one of the transition from ROI fluoroscopy to SPOT fluoroscopy and the transition from SPOT fluoroscopy to ROI fluoroscopy. Can be stopped. Thereby, the exposure to the subject P can be reduced during the movement period of the aperture blade 155.

  Further, according to the present embodiment, during execution of the SPOT fluoroscopy, the movement of the top plate 21, the movement of the support frame 19, the movement of the position of the region of interest, the change of the size of the region of interest, The X-ray diaphragm device 15 can be controlled to shift from the SPOT fluoroscopy to the ROI fluoroscopy in response to at least one execution of enlargement or reduction. That is, if various operations indirectly or directly related to the region of interest in SPOT fluoroscopy occur, ROI fluoroscopy can be executed to obtain a non-ROI image suitable for the composite image 231. Thereby, a non-ROI image suitable for the composite image 231 displayed during execution of the SPOT fluoroscopy can be acquired, and a shift between the ROI image and the non-ROI image in the composite image 231 can be suppressed.

  Further, according to the present embodiment, during the execution of the ROI fluoroscopy after the transition from the SPOT fluoroscopy to the ROI fluoroscopy, the movement of the top plate 21, the movement of the support frame 19, the movement of the region of interest, and the region of interest If the size change and the enlargement or reduction of the region of interest are not executed, the X-ray diaphragm device 15 can be controlled to shift from the ROI fluoroscopy performed again to the SPOT fluoroscopy. That is, SPOT fluoroscopy can be basically performed if there are no various operations indirectly or directly related to the region of interest. Thereby, the execution time of ROI fluoroscopy can be shortened, and the exposure dose with respect to the non-interest area | region in the subject P can be reduced.

(First modification)
The difference from the present embodiment is that when the execution time of the SPOT fluoroscopy reaches a predetermined period, the X-ray diaphragm device 15 is controlled to shift from the SPOT fluoroscopy to the ROI fluoroscopy. Note that the processing in this modification can be combined with the processing in the above embodiment.

  The memory circuit 31 stores a predetermined period. The predetermined period can be arbitrarily set according to the fluoroscopic target region, the age of the subject P, and the like, for example, several minutes. Note that the predetermined period is not only set at the stage until installation of the device, but also set / changed during use by the user, or automatically set / changed based on the history of operations by the user. May be. That is, the predetermined period may be set by the time of determining whether to switch the SPOT fluoroscopy to the ROI fluoroscopy (step Sa6).

  For example, in the process of step Sa6, the control circuit 29 uses the determination function 297 to determine whether or not the execution time of the SPOT fluoroscopy has reached a predetermined period. When the execution time of the SPOT fluoroscopy reaches a predetermined period, the control circuit 29 controls the X-ray diaphragm device 15 to shift from the SPOT fluoroscopy to the ROI fluoroscopy.

  Through the control as described above, according to the present modification, ROI fluoroscopy can be executed every predetermined period even if various operations indirectly or directly related to the region of interest in SPOT fluoroscopy do not occur. Therefore, the non-interest region of the composite image 231 can be updated every predetermined period. That is, according to the present modification, the latest non-ROI image can be obtained every predetermined period even if the subject P moves, and therefore, the deviation between the ROI image and the non-ROI image in the composite image 231 is reduced. Can be suppressed.

(Second modification)
The difference from the present embodiment is that when the pixel value of at least one pixel included in the edge portion of the region of interest in the SPOT fluoroscopic image or the synthesized image 231 is out of a predetermined range, the SPOT fluoroscopic image shifts to the ROI fluoroscopic image. In addition, the X-ray diaphragm device 15 is controlled. Note that the processing in this modification can be combined with the processing in the embodiment and the first modification.

  The storage circuit 31 stores a predetermined range. The predetermined range is a range of pixel values defined by upper and lower limit pixel values in the edge portion of the region of interest of the composite image 231. The upper and lower limit pixel values are values that affect the pixel value when the fluoroscopic condition is changed by automatic brightness adjustment, for example. Note that the predetermined range in this modification is not only set at the stage until the installation of the device, but is also set / changed during use by the user, or automatically set / changed based on the history of operations by the user. It may be changed. That is, the predetermined range only needs to be set before the determination (step Sa6) whether or not to switch the SPOT fluoroscopy to the ROI fluoroscopy.

  For example, in the process of step Sa6, the control circuit 29 determines whether or not the pixel value of at least one pixel included in the edge portion of the region of interest in the SPOT fluoroscopic image or the composite image is out of the pixel value range by the determination function 297. Determine whether. The comparison target with the range of pixel values may be an average value or a median value of a plurality of pixel values corresponding to a plurality of pixels included in the edge portion. The control circuit 29 monitors pixel values included in the edge portion during execution of SPOT fluoroscopy. The control circuit 29 controls the X-ray aperture device 15 to shift from SPOT fluoroscopy to ROI fluoroscopy when the pixel value of at least one pixel included in the edge portion is out of the range of pixel values.

  FIG. 10 is a diagram illustrating an example of the region of interest 2311, the edge portion 2313 in the region of interest 2311, and the non-region of interest 2315 in the composite image 231. As shown in FIG. 10, the region of interest 2311 corresponds to the inside of the one-dot chain line. The edge portion 2313 in the region of interest 2311 corresponds to a region hatched with a point in FIG. 10, that is, a region surrounded by a one-dot chain line and a dotted line. The width of the edge portion 2313 is preset to an arbitrary number of pixels.

  By the control as described above, according to the present modification, even if various operations related indirectly or directly to the region of interest 2311 in the SPOT fluoroscopy do not occur, the region of interest 2311 in the SPOT fluoroscopic image or the synthesized image 231 is displayed. When the pixel value of at least one pixel included in the edge portion 2313 is out of a predetermined range, the X-ray diaphragm device 15 can be controlled to shift from SPOT fluoroscopy to ROI fluoroscopy. That is, according to this modification, a non-ROI image can be obtained when the monitored pixel value is out of the range of pixel values, and a shift between the ROI image and the non-ROI image in the composite image 231 is suppressed. can do.

(Third Modification)
The difference from the present embodiment is that a pixel value of at least one pixel included in the edge portion 2313 of the region of interest 2311 in the composite image 231 and a pixel adjacent to this pixel and included in the non-interest region 2315 The difference value with the pixel value is calculated, and when the calculated difference value is out of a predetermined range, the X-ray diaphragm unit 15 is controlled to shift from the SPOT fluoroscopy to the ROI fluoroscopy. Note that the processing in this modification can be combined with the processing in the embodiment and the modification.

  The storage circuit 31 stores a predetermined range. The predetermined range is a range of difference values defined by upper and lower limit difference values. The difference value between the upper and lower limits is such a value that the boundary between the region of interest 2311 and the non-interest region 2315 is visually recognized in the composite image 231 when the fluoroscopic condition is changed by automatic brightness adjustment or the like. Note that the predetermined range in this modification is not only set at the stage until the installation of the device, but is also set / changed during use by the user, or automatically set / changed based on the history of operations by the user. It may be changed. That is, the predetermined range only needs to be set before the determination (step Sa6) whether or not to switch the SPOT fluoroscopy to the ROI fluoroscopy.

  For example, in the process of step Sa6, the control circuit 29 determines the pixel value of at least one pixel included in the edge portion 2313 of the region of interest 2311 in the composite image 231 and a pixel that is adjacent to the pixel and is a non-interest region. A difference value from the pixel value of the pixel included in 2315 is calculated. Next, the control circuit 29 uses the determination function 297 to determine whether the calculated difference value is out of the difference value range. Note that the comparison target with the range of the difference value is the average value of a plurality of pixel values corresponding to a plurality of pixels included in the edge portion 2313 and the edge portion of the non-interest area 2315 adjacent to the edge portion 2313. It may be a difference value from an average value of a plurality of pixel values corresponding to a plurality of included pixels. Further, a median value may be used instead of the average value. The control circuit 29 monitors the calculated difference value during execution of the SPOT fluoroscopy. When the calculated difference value is out of the range of the difference value, the control circuit 29 controls the X-ray diaphragm device 15 to shift from SPOT fluoroscopy to ROI fluoroscopy.

  FIG. 11 is a diagram illustrating an example of the region of interest 2311, the edge portion 2313 in the region of interest 2311, and the edge portion 2317 that is adjacent to the edge portion 2313 and included in the non-interest region 2315 in the composite image 231. is there. As shown in FIG. 11, the region of interest 2311 corresponds to the inside of the dashed-dotted frame. The edge portion 2313 in the region of interest 2311 corresponds to a region hatched with dots in FIG. The edge portion 2317 included in the non-interest region 2315 corresponds to a region hatched with diagonal lines from the upper left to the lower right in FIG. The widths of the edge portions 2313 and 2317 are set in advance to an arbitrary number of pixels.

  Through the control as described above, according to the present modification, the edge portion 2313 of the region of interest 2311 in the composite image 231 can be obtained even if various operations related indirectly or directly to the region of interest 2311 in SPOT fluoroscopy do not occur. A difference value between a pixel value of at least one pixel included in the pixel and a pixel value of a pixel adjacent to the pixel and included in the non-interest area 2315 is calculated, and the calculated difference value is the difference value When out of range, the X-ray diaphragm device 15 can be controlled to transition from SPOT fluoroscopy to ROI fluoroscopy. That is, according to the present modification, a non-ROI image can be obtained when the calculated difference value is out of the range of the difference value, and therefore, a shift between the ROI image and the non-ROI image is suppressed in the composite image 231. can do.

(Application examples)
This application example is to apply the fluoroscopic function to the distal end portion of the catheter inserted into the subject P.

  The control circuit 29 detects the distal end portion of the catheter in the ROI fluoroscopic image generated by the ROI fluoroscopy. Specifically, the control circuit 29 specifies the distal end portion of the catheter in the ROI fluoroscopic image by edge detection processing or the like on the ROI fluoroscopic image. The control circuit 29 sets the position of the opening region in the X-ray filter 151 so as to include the distal end portion of the catheter in the ROI fluoroscopic image. The control circuit 29 controls the X-ray filter driving device 153 to match the opening region 152 of the X-ray filter 151 with the region of interest according to the position of the region of interest in the ROI fluoroscopic image.

  The control circuit 29 uses the determination function 297 to determine whether or not the distal end portion of the catheter has moved in the ROI fluoroscopic image. For example, the control circuit 29 determines whether or not the distal end portion of the catheter is moved by subtracting the ROI fluoroscopic image generated immediately before from the current ROI fluoroscopic image. When detecting the movement of the distal end portion of the catheter in the ROI fluoroscopic image, the control circuit 29 sets the region of interest so as to include the distal end portion of the catheter. At this time, as described above, the control circuit 29 adjusts the opening region 152 of the X-ray filter 151 to the region of interest in accordance with the position of the region of interest including the distal end portion of the catheter. To control. The control circuit 29 performs the ROI fluoroscopy while moving the region of interest following the tip of the catheter while the movement of the catheter tip is detected in the ROI fluoroscopic image, that is, during the movement of the catheter tip. To do.

  When the distal end portion of the catheter is positioned in the vicinity of the end portion of the ROI fluoroscopic image due to the movement of the distal end portion of the catheter, the control circuit 29 determines whether the support frame 19 and the ceiling frame 19 are in accordance with the moving direction and the moving distance of the distal end portion of the catheter. It is also possible to control the drive device in order to move at least one of the plates 21. Thereby, according to this application example, the ROI fluoroscopic image can be generated following the movement of the distal end portion of the catheter. In addition, the control circuit 29 fixes the region of interest at the center of the ROI fluoroscopic image and follows the movement of the tip of the catheter so that the tip of the catheter is always included in the region of interest. It is also possible to control the movement of at least one of the top plate 21.

  In the ROI fluoroscopic image, the movement of the distal end portion of the catheter is not detected, that is, when the movement of the distal end portion of the catheter is stopped, the control circuit 29 controls the X-ray diaphragm device 15 in order to shift from the ROI fluoroscopy to the SPOT fluoroscopy. To do. The control circuit 29 identifies the distal end portion of the catheter in the composite image 231 by edge detection processing or the like on the composite image 231 generated during execution of the SPOT fluoroscopy. The control circuit 29 uses the determination function 297 to determine whether or not the distal end portion of the catheter has moved during execution of the SPOT fluoroscopy. For example, the control circuit 29 determines the presence or absence of movement of the distal end portion of the catheter by subtracting the composite image generated immediately before from the current composite image 231. When the movement of the distal end portion of the catheter is detected during execution of the SPOT fluoroscopy, the control circuit 29 controls the X-ray diaphragm device 15 to shift from the SPOT fluoroscopy to the ROI fluoroscopy. The control circuit 29 performs SPOT fluoroscopy in a period in which the movement of the distal end portion of the catheter is not detected in the synthesized image 231, that is, in a stop period of the distal end portion of the catheter.

  Hereinafter, the above process is repeated until the fluoroscopic function in the present embodiment is completed. It should be noted that in the transition from ROI fluoroscopy to SPOT fluoroscopy and from SPOT fluoroscopy to ROI fluoroscopy, it is also possible to use various processes in the above-described embodiments and modifications.

  Through the control described above, according to this application example, the position of the opening region is set so as to include the distal end portion of the catheter by detecting the distal end portion of the catheter in the ROI fluoroscopic image, and the movement of the distal end portion of the catheter is controlled. With the detection as an opportunity, the X-ray diaphragm 15 is controlled to shift from the SPOT fluoroscopy to the ROI fluoroscopy, the ROI fluoroscopy is executed during the movement of the catheter tip, and the movement of the catheter tip is stopped. The X-ray diaphragm device 15 is controlled to shift from ROI fluoroscopy to SPOT fluoroscopy, and SPOT fluoroscopy can be performed during the stop period of the distal end portion of the catheter. Thereby, according to this application example, it becomes possible to set the region of interest following the distal end portion of the catheter, and furthermore, switching between ROI fluoroscopy and SPOT fluoroscopy according to the presence or absence of movement of the distal end portion of the catheter. Can do.

  According to the X-ray diagnostic apparatus 1 described in the above-described embodiment, at least one modified example, and application example, when performing the SPOT fluoroscopy, an image of the periphery of the ROI is obtained while performing dose reduction corresponding to the SPOT fluoroscopy. Can be displayed.

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

  DESCRIPTION OF SYMBOLS 1 ... X-ray diagnostic apparatus, 11 ... High voltage generator, 13 ... X-ray tube, 15 ... X-ray aperture device, 17 ... X-ray detector, 19 ... Support frame, 21 ... Top plate, 23 ... Image generation circuit, 25 ... Communication interface circuit, 27 ... Input interface circuit, 29 ... Control circuit, 30 ... Processing circuit, 31 ... Memory circuit, 33 ... Display circuit, 131 ... Illumination range, 133 ... X-ray emission window, 135 ... Tube focus, 151 ... X-ray filter, 152 ... X-ray filter opening area, 153 ... X-ray filter driving device, 154 ... Diaphragm blade opening area, 155 ... Diaphragm blade, 157 ... Diaphragm blade driving device, 231 ... Composite image, 291 ... X-ray filter control function, 293 ... aperture control function, 295 ... automatic brightness adjustment function, 297 ... determination function, 301 ... image generation function, 303 ... display control function, 2311 ... region of interest, 2313 ... Marginal part of the heart in the region, 2315 ... non-interest area, 2317 ... marginal part in the non-region of interest.

Claims (13)

An X-ray detector that faces the X-ray tube that generates X-rays and detects the X-ray;
An X-ray diaphragm apparatus having an X-ray filter having a partial area or an opening area having a larger X-ray transmittance than other areas, and a diaphragm blade for shielding the X-ray;
When shifting from the first fluoroscopy using the X-ray filter to the second fluoroscopy using the diaphragm blades in order to limit the irradiation range, the X-ray filter passes outside the opening region or the partial region. A control unit that controls the X-ray diaphragm device so as to shield the X-ray;
A first fluoroscopic image is generated based on an output from the X-ray detector during execution of the first fluoroscopy, and a second fluoroscopic image is generated based on an output from the X-ray detector during execution of the second fluoroscopy. A non-interest area image corresponding to an X-ray irradiation area that has passed outside the opening area or the partial area in the first fluoroscopic image during execution of the second fluoroscopic image, and the second fluoroscopic image. An image generation unit that generates a combined image obtained by combining a region-of-interest image corresponding to an X-ray irradiation region that has passed through the opening region or the partial region;
A display control unit that displays the first fluoroscopic image on a display unit during execution of the first fluoroscopy, and displays the composite image on the display unit during execution of the second fluoroscopy;
An X-ray diagnostic apparatus comprising: In the first fluoroscopic image, the image generation unit reduces the contrast of a plurality of pixel values corresponding to an X-ray irradiation region that has passed outside the opening region or the partial region by using the X-ray filter. Generating the non-region-of-interest image by compensating accordingly.
The X-ray diagnostic apparatus according to claim 1. The control unit controls the X-ray diaphragm device triggered by the generation of a plurality of the first fluoroscopic images during execution of the first fluoroscopy,
The image generation unit generates the non-region-of-interest image by averaging pixel values of the plurality of first perspective images at pixels at the same position;
The X-ray diagnostic apparatus according to claim 1 or 2. The control unit controls the X-ray diaphragm device when a luminance level of the first fluoroscopic image becomes constant over a predetermined time within a target range during execution of the first fluoroscopy,
The X-ray diagnostic apparatus according to claim 1 or 2. The control unit obtains the first fluoroscopy immediately before stopping the application of the high voltage to the X-ray tube during the operation period of the diaphragm blade at the time of transition from the first fluoroscopy to the second fluoroscopy. Continuously displaying the first fluoroscopic image;
The X-ray diagnostic apparatus as described in any one of Claims 1 thru | or 4. A bed that movably supports the top plate on which the subject is placed;
A support frame that movably supports the X-ray tube and the X-ray detector;
During execution of the second fluoroscopy, the control unit moves the top plate, moves the support frame, moves a position of the region of interest, changes the size of the region of interest, and changes the size of the region of interest. Controlling the X-ray diaphragm device so as to shift from the second perspective to the first perspective in response to at least one of enlargement or reduction.
The X-ray diagnostic apparatus as described in any one of Claims 1 thru | or 5. The controller is configured to move the top plate, move the support frame, and move the position of the region of interest during execution of the first perspective after the transition from the second perspective to the first perspective. If the change of the size of the region of interest and the enlargement or reduction of the region of interest are not executed, the X-ray diaphragm device is controlled so as to shift from the first fluoroscopy performed again to the second fluoroscopy. To
The X-ray diagnostic apparatus according to claim 6. The control unit controls the X-ray diaphragm device to shift from the second fluoroscopy to the first fluoroscopy when the execution time of the second fluoroscopy reaches a predetermined period.
The X-ray diagnostic apparatus as described in any one of Claims 1 thru | or 5. The control unit changes from the second perspective to the first perspective when a pixel value of at least one pixel included in a marginal portion of the region of interest in the second perspective image or the composite image is out of a predetermined range. Controlling the X-ray diaphragm device to shift,
The X-ray diagnostic apparatus as described in any one of Claims 1 thru | or 5. The control unit includes a difference between a pixel value of at least one pixel included in a marginal portion of the region of interest in the composite image and a pixel value of a pixel adjacent to the pixel and included in the non-interest region. A value is calculated, and when the difference value is out of a predetermined range, the X-ray diaphragm device is controlled to shift from the second perspective to the first perspective,
The X-ray diagnostic apparatus as described in any one of Claims 1 thru | or 5. The control unit stops application of a high voltage to the X-ray tube during an operation period of the diaphragm blades at the time of transition from the second perspective to the first perspective;
The X-ray diagnostic apparatus as described in any one of Claims 7 thru | or 10. The opening region or the partial region is set at a non-center of the first perspective image.
The X-ray diagnostic apparatus as described in any one of Claims 1 thru | or 11. The controller is
By detecting the distal end portion of the catheter in the first fluoroscopic image, the position of the opening region or the partial region is set so as to include the distal end portion,
With the detection of the movement of the tip portion as a trigger, the X-ray diaphragm device is controlled to shift from the second fluoroscopy to the first fluoroscopy,
Performing the first perspective during movement of the tip portion;
Controlling the X-ray diaphragm device so as to shift from the first fluoroscopy to the second fluoroscopy with the stop of the movement of the tip part,
Performing the second fluoroscopy in the stop period of the tip portion;
The X-ray diagnostic apparatus according to claim 1.