JP2008000220A - X-ray diagnostic apparatus, control method thereof and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily obtain the state and photography position of a photographed image in long-object photographing. <P>SOLUTION: An X-ray diaphragm 4 for an X-ray diagnostic apparatus 1 forms an irradiation field for obtaining a fluoroscopic image and a field for obtaining a photographed image. A drive control part 14 changes a region of a patient P which is irradiated with an X-ray of the irradiation field for obtaining the photographed image (a photographing area) along a direction 2a of a body axis. A DR apparatus 15 forms a fluoroscopic image of a prescribed region of the patient based on detected data output from an X-ray detector 5 in irradiation with an X-ray of the irradiation field for obtaining the fluoroscopic image. On the basis of detected data output in irradiation with an X-ray of the irradiation field for obtaining the photographed image concerning each photographing area, the DR apparatus 15 forms a photographed image of the photographing area. An arithmetic control part 11 makes a display part 17 display the fluoroscopic image and display the photographed image of the photographing area superposed on the fluoroscopic image based on a positional relationship of the prescribed region and the photographing area. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an X-ray diagnostic apparatus that irradiates a subject with X-rays and forms and displays an image based on the dose of X-rays transmitted through the subject, a control method thereof, and a program.

  An X-ray diagnostic apparatus is an apparatus that images and displays an internal form of a subject by irradiating the subject with X-rays and detecting a dose of X-rays transmitted through the subject.

  FIG. 11 shows an external configuration of a general X-ray diagnostic apparatus (a console including a display device and an operation device is not shown). This X-ray diagnostic apparatus includes a main body 1002 supported on a floor surface by a support base 1001, a bed 1003 on which a subject (not shown) is placed, and a holding arm that holds an X-ray irradiation apparatus 1006. 1004.

  The X-ray irradiation apparatus 1006 is provided with an X-ray tube 1006a that generates X-rays and an X-ray diaphragm 1006b that forms an irradiation field of X-rays generated from the X-ray tube 1006a.

  The bed 1003 and the holding arm 1004 are connected to the main body 1002 through a drive mechanism 1005. The drive mechanism 1005 acts to incline the bed 1003 and the holding arm 1004 by rotating them integrally.

  An X-ray detector (not shown) is provided inside or under the bed 1003 so as to face the X-ray irradiation apparatus 1006 with the subject interposed therebetween. As this X-ray detector, an image intensifier, an X-ray flat panel detector, or the like is used.

  The holding arm 1004 (X-ray irradiation apparatus 1006) and the X-ray detector can be moved in the longitudinal direction of the bed 1003 (the body axis direction of the object to be placed) and the short direction perpendicular thereto by a driving mechanism (not shown). The imaging part of the subject can be changed.

  Conventionally, a technique called long imaging has been used as an imaging technique using an X-ray diagnostic apparatus. Long-length imaging is intended for imaging a range wider than the imaging area of a single image, that is, a range wider than the detection surface (field-of-view area) of the X-ray detector. In this method, a plurality of obtained images are connected (attached) to form image data of one image (see, for example, Patent Document 1).

  Long imaging performed using the X-ray diagnostic apparatus of FIG. 11 will be described with reference to FIGS. 12 and 13. Here, a case where two images are taken and pasted together will be described. When the user performs a predetermined operation and selects the long imaging mode, the movement of the bed 1003 in the short direction is prohibited, and only the movement of the subject in the body axis direction is allowed. Further, as shown in FIG. 13A, the user sets the shooting areas g1 and g2 for the two images. Here, the imaging regions g1 and g2 are set so as to have an overlapping region g12 in order to suitably combine the images.

  An arrow A in FIG. 12 represents a moving state of the video system for arranging the video system (X-ray irradiation apparatus 1006 and X-ray detector) in the two imaging regions g1 and g2. The positions of the video system before and after the movement are referred to as a first shooting position and a second shooting position, respectively. The X-ray irradiation apparatus 1006 includes an X-ray tube 1006a and an X-ray diaphragm 1006b. A reference numeral 1007a in FIG. 12 represents the position of the detection surface of the X-ray detector. In addition, symbols B1 and B2 in FIG. 12 represent regions (X-ray passing regions) through which X-rays irradiated at the first and second imaging positions pass, respectively.

  The X-ray diagnostic apparatus first arranges a video system at the first imaging position and images an image corresponding to the imaging region g1. A photographed image G1 in FIG. 13B shows an image photographed at the first photographing position. Position information (coordinate values) of the first shooting position in the longitudinal direction of the bed 1003 is added to the image data of the shot image G1.

  Next, the video system is moved from the first shooting position to the second shooting position, and an image corresponding to the shooting area g2 is shot. A photographed image G2 in FIG. 13C shows an image photographed at the second photographing position. Position information (coordinate values) of the second shooting position in the longitudinal direction of the bed 1003 is added to the image data of the shot image G2.

  Subsequently, the X-ray diagnostic apparatus pastes the captured image G1 and the captured image G2. At this time, for example, as shown in FIG. 13D, the captured images G1 and G2 are pasted so that the center position GM of the overlapping region g12 is a boundary. This bonding process is performed on the position information of the first and second imaging positions, the distance between the X-ray tube 1006a and the detection surface of the X-ray detector, and the X-ray passage area formed by the X-ray diaphragm 1006b. Based on this, a bonding position (center position GM) is obtained.

  The photographed images G1 and G2 may be photographed by the user changing the photographing position while visually confirming the photographed image and repeating one-shot photographing, or at a predetermined photographing time interval (for example, two frames). / Sec), the user may change the shooting position while performing continuous shooting.

JP 2004-358254 A

  When long imaging is performed using the conventional X-ray diagnostic apparatus as described above, the following problems are pointed out.

  In long shooting, it is necessary to take a picture while checking the state of the photographed image (for example, the state of arrival of the contrast medium when using a contrast agent) and the photographing position of the photographed image. It is desirable to be able to grasp the position of bones and blood vessels by widening the area.

  In order to secure a wide imaging region, it is necessary to widen the field of view of the X-ray detector by opening the X-ray stop 1006b and increasing the X-ray irradiation angle (X-ray passing region). Then, a positional shift occurs in the X-ray imaged on the detection surface 1007a of the X-ray detector due to the difference in the position of the subject in the body thickness direction (the direction connecting the X-ray irradiation apparatus 1006 and the X-ray detector). As a result, there arises a problem that accuracy when the photographed images are pasted is lowered.

  This problem will be specifically described with reference to positions P1 and P2 in FIG. The positions P1 and P2 differ only in the position of the subject P in the body thickness direction (the position P1 is disposed closer to the X-ray irradiation apparatus 1006 and the position P2 is disposed closer to the detection surface 1007a). In addition, since the shooting area of each image is set wide, the distance from the first shooting position to the second shooting position, that is, the moving distance in the body axis direction of the video system becomes relatively long. Yes.

  First, for X-rays passing through the position P1, between the imaging position when the video system is arranged at the first imaging position and the imaging position when arranged at the second imaging position, An imaging position shift Δ1 in the body axis direction of the subject P occurs. On the other hand, for the X-rays passing through the position P2, similarly, an imaging position deviation Δ2 (<Δ1) occurs in the body axis direction of the subject P. The imaging position shift increases as the position is closer to the X-ray irradiation apparatus 1006. As described above, even if the position in the body axis direction is the same, if the position in the body thickness direction is different, the amount of image formation position deviation is also different. End up. This imaging position deviation increases in proportion to the moving distance of the video system in the body axis direction.

  In addition, when the imaging region of each image is set wide, the scattered radiation due to the interaction between the subject P and the X-rays increases, density unevenness occurs in the image of the bonded portion, and the bonding accuracy decreases. Also occurs.

  If the moving distance in the body axis direction of the video system is shortened while setting a wide imaging region in order to cope with such a problem, an overlapping region of adjacent images increases, and unnecessary exposure of the subject P increases. A new problem arises.

  In order to deal with this new problem, for example, as shown in FIG. 14, when taking a picture with a strip-shaped imaging region gj (j = 1, 2,...) Having a short length in the body axis direction. As described above, it becomes difficult to grasp the state of the photographic image and the photographing position, and long photographing cannot be suitably performed.

  The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to easily grasp the state and position of a captured image in long imaging using an X-ray diagnostic apparatus. To provide technology.

  In addition, the present invention prevents a reduction in the accuracy of bonding of captured images caused by a deviation in the X-ray imaging position based on a difference in the position of the subject in the body thickness direction in long imaging using an X-ray diagnostic apparatus. Another object is to provide a technology that makes it possible to plan.

  It is still another object of the present invention to provide a technique that makes it possible to reduce unnecessary exposure of a subject in long imaging using an X-ray diagnostic apparatus.

  In order to achieve the above object, the invention described in claim 1 includes a bed, X-ray generation means for generating X-rays, irradiation field forming means for forming an irradiation field of the generated X-rays, and An X-ray detection unit that is disposed at a position facing the X-ray diaphragm across a bed, detects X-rays transmitted through the subject placed on the bed, and outputs detection data; the bed; X-ray generation means, irradiation field forming means, and X-ray detection means are moved relative to each other along the body axis direction of the subject, and the subject is based on the output detection data. An X-ray diagnostic apparatus comprising: an image forming unit that forms an image representing an internal form of the display; a display unit; and a display control unit that displays the formed image on the display unit. Are the first irradiation field of the X-ray and the first illumination. The second irradiation field having a shorter length in the body axis direction than the field is formed by switching, and the driving means is irradiated with the X-ray of the second irradiation field by the relative movement. The body part of the subject is changed along the body axis direction, and the image forming unit is configured to detect the subject based on the output detection data when the X-ray of the first irradiation field is irradiated. A detection image that is output when X-rays of the second irradiation field are irradiated to each of the regions of the subject that are changed by the driving unit while forming a fluoroscopic image of a predetermined region. Based on the data, a captured image of the part is formed, and the display control unit causes the display unit to display the fluoroscopic image of the predetermined part, and the position of the subject part with respect to the predetermined part Based on relationship There are, to be displayed over the photographic image of the site on the fluoroscopic image, characterized in that.

  The invention according to claim 2 is the X-ray diagnostic apparatus according to claim 1, wherein the irradiation field forming means has a length in the body axis direction as the second irradiation field. A substantially rectangular irradiation field shorter than a length in a direction orthogonal to the axial direction is formed, and the image forming unit substantially corresponds to the substantially rectangular irradiation field as each captured image of the region of the subject. A rectangular photographed image is formed.

  The invention described in claim 3 is the X-ray diagnostic apparatus according to claim 1, wherein the length of the irradiation field formed by the irradiation field forming means in the body axis direction and the predetermined portion of the X-ray diagnostic apparatus. Based on the length in the body axis direction, the image processing apparatus further includes calculation means for obtaining a photographing position of the photographed image, and the driving means determines whether the X-ray of the second irradiation field is based on the obtained photographing position. The change of the portion of the subject to be irradiated is performed.

  According to a fourth aspect of the present invention, there is provided the X-ray diagnostic apparatus according to the first aspect, wherein the radiography is performed based on the number of radiographed images and the length of the predetermined part in the body axis direction. The image processing apparatus further includes calculation means for obtaining an imaging position of the image, and the driving means performs the change of the region of the subject irradiated with the X-rays of the second irradiation field based on the obtained imaging position. It is characterized by performing.

  Further, the invention described in claim 8 is a bed, an X-ray generation unit that generates X-rays, an irradiation field forming unit that forms an irradiation field of the generated X-ray, and the X across the bed. An X-ray detector that is disposed at a position facing the line diaphragm and detects X-rays transmitted through the subject placed on the bed and outputs detection data; the bed; the X-ray generator; An image representing an internal form of the subject based on the output detection data and a driving unit that relatively moves the irradiation field forming unit and the X-ray detection unit along the body axis direction of the subject. Operation control by switching between an image forming means for forming a display, a display means, a fluoroscopic image acquisition operation for acquiring a fluoroscopic image of the subject, and a captured image acquisition operation for acquiring a captured image of the subject An X-ray diagnostic apparatus having control means for performing Thus, the control means controls the irradiation field forming means to form the first irradiation field during the fluoroscopic image acquisition operation, and detects the detection data corresponding to the first irradiation field as the X-ray detection. And outputting a fluoroscopic image formed by the image forming unit on the display unit based on the detection data, and controlling the irradiation field forming unit during the captured image acquisition operation to control the first field. A second irradiation field having a shorter length in the body axis direction than the irradiation field is formed, and the drive unit is controlled to change a part of the subject to be irradiated with the X-rays of the second irradiation field. In addition, the X-ray detection unit outputs detection data corresponding to each part of the subject, and a captured image formed by the image forming unit based on the detection data corresponding to each part of the subject. The Based on the positional relationship between the position and the fluoroscopic image to be displayed superimposed on the displayed the fluoroscopic image, characterized in that.

  According to a ninth aspect of the present invention, there is provided a bed, X-ray generation means for generating X-rays, irradiation field forming means for forming an irradiation field of the generated X-rays, and the X across the bed. An X-ray detector that is disposed at a position facing the line diaphragm and detects X-rays transmitted through the subject placed on the bed and outputs detection data; the bed; the X-ray generator; An image representing an internal form of the subject based on the output detection data and a driving unit that relatively moves the irradiation field forming unit and the X-ray detection unit along the body axis direction of the subject. An image forming means for forming a display image, and a display means, and a fluoroscopic image acquisition operation for acquiring a fluoroscopic image of the subject and a captured image acquisition operation for acquiring a captured image of the subject A method for controlling an X-ray diagnostic apparatus to be executed, comprising: At the time of the acquisition operation, the step of forming the first irradiation field in the irradiation field forming unit, the step of outputting the detection data corresponding to the first irradiation field to the X-ray detection unit, and the detection data Causing the image forming unit to form a fluoroscopic image, and causing the display unit to display the formed fluoroscopic image, and at the time of the captured image acquisition operation, the body is more than the first irradiation field. A step of causing the irradiation field forming means to form a second irradiation field having a short axial length; and a step of causing the driving means to change the site of the subject irradiated with the X-rays of the second irradiation field. A step of outputting detection data corresponding to each part of the subject to the X-ray detection means, and a captured image based on the detection data corresponding to each part of the subject Causing the image forming unit to form the image, and causing the formed photographed image to be displayed over the displayed fluoroscopic image based on a positional relationship between the part and the fluoroscopic image. It is characterized by that.

  The invention described in claim 10 is characterized in that a bed, X-ray generation means for generating X-rays, irradiation field forming means for forming an irradiation field of the generated X-rays, and the X across the bed. An X-ray detector that is disposed at a position facing the line diaphragm and detects X-rays transmitted through the subject placed on the bed and outputs detection data; the bed; the X-ray generator; An image representing an internal form of the subject based on the output detection data and a driving unit that relatively moves the irradiation field forming unit and the X-ray detection unit along the body axis direction of the subject. An image forming means for forming a display image, and a display means, and a fluoroscopic image acquisition operation for acquiring a fluoroscopic image of the subject and a captured image acquisition operation for acquiring a captured image of the subject A program for controlling an X-ray diagnostic apparatus to be executed At the time of the fluoroscopic image acquisition operation, a step of causing the irradiation field forming unit to form a first irradiation field, a step of causing the X-ray detection unit to output detection data corresponding to the first irradiation field, and the detection data The image forming unit is configured to perform a step of forming a fluoroscopic image on the basis of the image forming unit, and a step of displaying the formed fluoroscopic image on the display unit. And forming a second irradiation field having a short length in the body axis direction in the irradiation field forming means, and a portion of the subject irradiated with X-rays of the second irradiation field to the driving means. A step of changing, a step of outputting detection data corresponding to each part of the subject to the X-ray detection means, and a detection data corresponding to each part of the subject. A step of forming a photographed image on the image forming means, and a step of displaying the formed photographed image on the displayed fluoroscopic image based on a positional relationship between the part and the fluoroscopic image. , Is executed.

  The X-ray diagnostic apparatus according to claim 1 is an irradiation field forming unit configured to switch between a first irradiation field of X-rays and a second irradiation field having a shorter length in the subject body axial direction. , Driving means for changing the region of the subject irradiated with the X-ray of the second irradiation field along the body axis direction, and output from the X-ray detection means when the X-ray of the first irradiation field is irradiated Based on the detected data, a fluoroscopic image of a predetermined part of the subject is formed, and for each X-ray irradiation part of the second irradiation field changed by the driving means, detection output from the X-ray detection means Image forming means for forming a photographed image of the part based on the data.

  Then, the display control means causes the display means to display a fluoroscopic image of the predetermined part, and displays a photographed image formed for each irradiation part of the X-ray of the second irradiation field with respect to the predetermined part. Based on the relationship, the image is displayed so as to be superimposed on the fluoroscopic image.

  According to such an X-ray diagnostic apparatus, since the position of each captured image can be grasped based on the fluoroscopic image when performing long photographing, the position of the photographed image can be easily grasped.

  Furthermore, when performing long imaging using a contrast medium, it is possible to easily determine whether the contrast medium has reached the imaging area of the captured image by checking the state of the captured image. Such confirmation of the state of the photographed image can be applied not only in the case of using a contrast agent but also in any photographing mode in which the state of the photographed image changes with time.

  According to the X-ray diagnostic apparatus of the second aspect, the substantially rectangular second irradiation field whose length in the body axis direction is shorter than the length in the direction orthogonal thereto is formed. Since it is configured to form a substantially rectangular photographed image corresponding to the irradiation field, the difference in the photographing position (distance in the body axis direction) of adjacent photographed images acquired in long photographing is reduced. Can do. Therefore, it is possible to reduce the amount of movement when moving from a shooting area of a certain shooting image to a shooting area of a shooting image adjacent thereto. As a result, the X-ray imaging position shift based on the difference in the position of the subject in the body thickness direction is reduced, and it is possible to prevent a decrease in the accuracy of pasting of the captured images due to this image forming position shift. .

  The X-ray diagnostic apparatus according to claim 3 or 4 is configured to calculate a photographing position of a photographed image and acquire a photographed image based on the computed photographing position. At this time, the above calculation processing can be executed so as to obtain an imaging position in which the length in the body axis direction of the overlap region of adjacent captured images is reduced, thereby eliminating the need for the subject in long imaging. It becomes possible to reduce exposure.

  According to the invention described in claim 8, claim 9, or claim 10, a fluoroscopic image is formed and displayed based on the detection data output from the X-ray detection means corresponding to the first irradiation field. The X-ray irradiation part of the second irradiation field whose length in the body axis direction is shorter than that of the first irradiation field is changed and output from the X-ray detection means corresponding to each part. Since it is configured to operate so as to form a captured image based on the detected data and display it on the fluoroscopic image, the position of each captured image is determined based on the fluoroscopic image when performing long shooting. It is possible to grasp and the position of the photographed image can be easily grasped.

  An example of a preferred embodiment of an X-ray diagnostic apparatus according to the present invention will be described in detail with reference to the drawings.

[Device configuration]
FIG. 1 shows an example of the configuration of an X-ray diagnostic apparatus according to the present invention. The X-ray diagnostic apparatus 1 shown in the figure includes a bed 2, an X-ray tube 3, an X-ray diaphragm 4, and an X-ray detector 5 similarly to the conventional configuration shown in FIGS. 11 and 12. In addition, the X-ray diagnostic apparatus 1 is provided with an arithmetic control unit 11, an X-ray control unit 12, an aperture control unit 13, a drive control unit 14, a DR device 15, and a user interface 16 as in the prior art. Note that the X-ray diagnostic apparatus 1 has the same external configuration as that of FIG. 11, for example.

  The user interface 16 is provided with a display unit 17 and an operation unit 18. The display unit 17 is configured by a display device of an arbitrary form such as a CRT (Cathode Ray Tube) display or an LCD (Liquid Crystal Display). The display unit 17 displays various screens and images under the control of the arithmetic control unit 11. The display unit 17 functions as an example of the “display unit” of the present invention.

  The operation unit 18 is configured by an arbitrary type of operation device or input device such as a keyboard, a mouse, a trackball, a joystick, or a control panel. The calculation control unit 11 receives an operation signal output from the operation unit 18 based on the performed operation, and executes control and calculation corresponding to the operation content. The operation unit 18 functions as an example of the “operation means” of the present invention.

  In FIG. 1, the display unit 17 and the operation unit 18 are described separately, but they can be integrally configured, for example, as a touch panel type LCD or a pen tablet.

  The subject P is placed on the bed (the top plate) 2. As shown in FIG. 11, the subject P is placed with its body axis direction aligned with the longitudinal direction of the bed 2. 1 indicates the longitudinal direction of the bed 2 (the body axis direction of the subject P).

  The X-ray tube 3 is a vacuum tube that generates X-rays. A heating current is supplied to the filament (cathode) to emit electrons, and a high voltage is applied between the filament and the tungsten anode to accelerate the electrons and collide with the tungsten anode. X-rays are generated when the accelerated electrons collide with the tungsten anode. The X-ray tube 3 functions as an example of the “X-ray generation means” of the present invention.

  Although not shown in the figure, the X-ray control unit 12 is provided with a high voltage generation unit that generates a high voltage and a control unit (such as a microprocessor) that controls the high voltage generation unit. Yes. Application of high voltage is, for example, a high-frequency inverter system, that is, a 50/60 Hz AC power supply is rectified to direct current, converted to high frequency alternating current of several kHz or more, boosted, and rectified again. The method of applying is applied.

  The X-ray tube 3 generates X-rays having a predetermined intensity in response to the application of the high voltage generated by the high voltage generator. The high voltage value or current value applied to the X-ray tube 3 can be set by the user using the user interface 16 or can be configured to be set automatically.

  For example, as shown in FIG. 2, the X-ray diaphragm 4 is configured by arranging plate-shaped diaphragm blades 41, 42, 43, 44 made of a material that absorbs X-rays such as tungsten and molybdenum in four directions. ing. The aperture blades 41 to 44 are arranged such that their end surfaces are orthogonal to the end surfaces of adjacent blades, and the openings formed on the inner end surfaces of the aperture blades 41 to 44 are rectangular. .

  The diaphragm control unit 13 functions to form irradiation fields of various forms (sizes and shapes) by moving the diaphragm blades 41 to 44 of the X-ray diaphragm 4 respectively. The diaphragm control unit 13 is provided with an actuator that drives the diaphragm blades 41 to 44 and a control unit (such as a microprocessor) that controls the actuator. The diaphragm control unit 13 moves the diaphragm blades 41 and 42 in the lateral direction 2b of the bed 2 (direction orthogonal to the longitudinal direction 2a), respectively, and moves the diaphragm blades 43 and 44 in the longitudinal direction 2a of the bed 2 respectively. (See FIG. 2).

  As described above, the X-ray diaphragm 4 controlled by the diaphragm control unit 13 causes the X-ray tube 3 to be the apex, and the X-ray detector 5 is the bottom surface to be the detection surface of the X-ray detector 5. (See FIG. 1) is formed, and an X-ray irradiation field corresponding to the X-ray passage region F is formed. The X-ray diaphragm 4 functions as an example of the “irradiation field forming means” of the present invention.

  Here, the irradiation field means a common area of the X-ray passing area and a plane crossing the X-ray passing area, in other words, an area where the X-ray is irradiated to the plane. For example, the X-ray irradiation field on the subject P is a plane including the longitudinal direction 2a and the short direction 2b, and is a region where the X-ray is irradiated to the plane passing through the subject P. Further, the X-ray irradiation field with respect to the detection surface of the X-ray detector 5 is a plane including the longitudinal direction 2 a and the short direction 2 b and is X with respect to a plane passing through the detection surface of the X-ray detector 5. The region is irradiated with a line (corresponding to an X-ray detection region described later). The shapes of these irradiation fields are similar when the X-ray passage region F is constant.

  The X-ray detector 5 operates to detect X-rays generated by the X-ray tube 3 and output the detection result (detection data) to the DR device 15. It functions as an example of “means”. The X-ray detector 5 is composed of, for example, an image intensifier or an X-ray flat panel detector.

  The image intensifier converts X-rays into light on a phosphor screen such as a scintillator, emits photoelectrons from a photocathode made in contact with the phosphor screen, and accelerates focusing with an electron lens made up of a focus electrode and an anode. Thus, an electronic image is formed on the output phosphor screen. Further, the image data (detection data) is obtained by converting the electronic image into a visible image on the output phosphor screen and photographing with a camera.

  The X-ray flat detector has a detection surface configured by arranging multi-row multi-column X-ray detection elements. As an X-ray detection element, an indirect conversion type in which X-rays are converted into light by a phosphor such as a scintillator and the light is converted into electric charge by a photoelectric conversion element such as a photodiode, or an electron hole in a semiconductor by X-rays. A direct conversion type using the generation of a pair and its movement to an electrode (that is, a photoconductive phenomenon) can be used. The X-ray flat panel detector converts X-rays into visible light and forms charge data (detection data) corresponding to the amount of visible light.

  The X-ray flat panel detector can read out charges in element units according to the arrangement of the X-ray detection elements. The detection data output from each element includes coordinate information of the element in a two-dimensional coordinate system based on a two-dimensional element array.

  The X-ray tube 3, the X-ray diaphragm 4 and the X-ray detector 5 form a moving unit 6 that can be moved integrally (for example, a configuration similar to the conventional one shown in FIGS. 11 and 12). Have). The moving unit 6 is moved by the drive control unit 14 in the longitudinal direction 2 a (body axis direction) and the short direction of the bed 2. The drive control unit 14 functions as an example of the “drive unit” of the present invention, and includes a drive mechanism that drives the moving unit 6 and a control unit (such as a microprocessor) that controls the operation of the drive mechanism. Composed. The moving unit 6 corresponds to the “video system” described in [Background Art].

  The DR (Digital Radiography) device 15 converts a detection data output from the X-ray detector 5 into a digital signal, and further performs various image processing and the like to form an image (image data). Consists of including. The DR device 15 functions as an example of the “image forming unit” of the present invention.

  Here, the X-ray diaphragm 4 forms a substantially quadrangular pyramid-shaped X-ray passage area F corresponding to the shape of the aperture formed by the diaphragm blades 41 to 44, and an X-ray detector corresponding to the X-ray passage area F Since the X-ray detection area 5 has a substantially rectangular shape (including a substantially square shape), the image formed by the DR device 15 is a substantially rectangular image corresponding to the shape of the opening.

  The arithmetic control unit 11 executes control of each part of the X-ray diagnostic apparatus 1 (in particular, control of the X-ray control unit 12, the aperture control unit 13, the drive control unit 14, and the user interface 16) and various arithmetic processes. The contents of the control and arithmetic processing executed by the arithmetic control unit 11 will be described in detail in the section [Usage pattern] below.

  The arithmetic control unit 11 includes, for example, a microprocessor such as a CPU (Central Processing Unit), a storage device (such as a memory or a hard disk drive) that stores a predetermined computer program and stores various data. The microprocessor executes control and arithmetic processing related to this embodiment by executing this computer program. This computer program corresponds to an example of the “program for controlling the X-ray diagnostic apparatus” of the present invention.

  The calculation control unit 11 functions as an example of the “display control means” and “calculation means” of the present invention. The arithmetic control unit 11 functions as an example of the “control unit” of the present invention.

[Usage form]
The usage pattern of the X-ray diagnostic apparatus 1 according to this embodiment will be described with further reference to FIGS. The flowchart shown in FIG. 3 represents an example of a usage pattern of the X-ray diagnostic apparatus 1.

  First, the outline of the usage pattern shown in this flowchart will be described. This mode of use is an example of use of the X-ray diagnostic apparatus 1 when a contrast medium is administered to the subject P and long imaging is performed (S1, S2). The long imaging by the X-ray diagnostic apparatus 1 is performed in two stages, that is, a stage of acquiring a fluoroscopic image (described later) of the subject P and a stage of acquiring a captured image.

  Here, the fluoroscopic image acquisition stage corresponds to an example of the “fluoroscopic image acquisition operation” of the present invention, and the captured image acquisition stage corresponds to an example of the “photographed image acquisition operation” of the present invention. .

  In the fluoroscopic image acquisition stage, the X-ray diagnostic apparatus 1 limits the movable direction of the moving unit 6 to the longitudinal direction 2a (S3), and the X-ray diaphragm 4 forms an irradiation field for fluoroscopic image shooting (S4). ), Information indicating the form of the irradiation field (aperture opening degree information) is stored (S5). Further, an X-ray detection area by the X-ray detector 5 corresponding to the aperture opening information is obtained (S6).

  The user observes the X-ray fluoroscopic image of the subject P and sets the imaging range (S7, S9). At that time, the X-ray diagnostic apparatus 1 acquires a fluoroscopic image including an imaging start position and a fluoroscopic image including an end position (S8 and S10), and pastes the acquired fluoroscopic images and displays them on the display unit 17. (S11).

  Next, the process proceeds to the captured image acquisition stage. First, the user sets a plurality of shooting regions (shooting positions) in long shooting (S12). The X-ray diagnostic apparatus 1 controls the X-ray diaphragm 4 so as to form an X-ray irradiation field corresponding to the set imaging region (S13).

  The X-ray diagnostic apparatus 1 acquires a captured image in response to a user's imaging request for each of a plurality of set imaging regions. At this time, the user proceeds with imaging while checking the captured image to determine whether or not the contrast agent has reached the imaging region. Then, every time a captured image is acquired, the X-ray diagnostic apparatus 1 causes the display unit 17 to display the captured image superimposed on the fluoroscopic image. (S14, S15, S16, S17, S18).

  Hereinafter, the operation of the X-ray diagnostic apparatus 1 in each of these steps S1 to S18 will be described in detail.

[Preparation stage: S1-S6]
First, a contrast medium is administered to the subject P (S1). Note that the timing of administering the contrast agent is appropriately determined in consideration of the time from the administration of the contrast agent until reaching the region to be imaged. For example, the contrast agent is administered after the imaging image acquisition stage. May be. The arrival time of the contrast medium is based on various conditions such as the distance between the intravenous injection position of the contrast medium and the site to be imaged, the type of contrast medium, and the blood flow velocity of the subject P.

  When the user selects the “long shooting mode” using the user interface 16 (S2), the calculation control unit 11 limits the movable direction of the moving unit 6 to the longitudinal direction (body axis direction) 2a (that is, The drive control unit 14 is controlled so as to prohibit the movement of the moving unit 6 in the short direction 2b (S3).

  Further, the diaphragm control unit 13 drives the diaphragm blades 41 to 44 of the X-ray diaphragm 4 based on the control from the calculation control unit 11 to form an irradiation field for acquiring a fluoroscopic image (S4). This irradiation field for obtaining a fluoroscopic image corresponds to an example of the “first irradiation field” of the present invention.

  Here, the “perspective image” is an image used for setting the imaging range of the subject P (described later). This fluoroscopic image is generally not required to be as detailed as an image (referred to as a “photographed image” used for medical treatment of the subject P. The fluoroscopic image is used for setting the photographing range of the photographed image).

  In consideration of such circumstances, in step S4, for example, the X-ray diaphragm 4 is fully opened (a diaphragm opening state in which the opening size is maximized), and at least the length in the longitudinal direction 2a is maximum. Control is performed so as to form an irradiation field such that In order to reduce unnecessary exposure of the subject P, it is possible to perform control so as to limit the length of the irradiation field in the short direction 2b.

  The arithmetic control unit 11 acquires information indicating the form of the irradiation field (opening) formed in step S4 (S5). This information (referred to as “aperture opening degree information”) includes at least information on the length in the longitudinal direction 2a of the opening formed by the aperture blades 41 to 44, for example.

  As the acquisition process in step S5, for example, the calculation control unit 11 itself may store the control content when the calculation control unit 11 controls the aperture control unit 13, and the throttle opening degree information may be acquired. The aperture control unit 13 that has driven the X-ray aperture 4 may generate the aperture opening information and send it to the calculation control unit 11, or a sensor (for example, aperture blades 41 to 44) that detects the shape of the aperture. The position of the opening may be directly detected by a position sensor or the like), and the detection result may be sent to the arithmetic control unit 11.

  Further, the calculation control unit 11 calculates a region (X-ray detection region) in which the X-ray detector 5 detects X-rays based on the aperture opening degree information acquired in step S5 (S6).

  Here, the X-ray tube 3, the X-ray diaphragm 4 and the X-ray detector 5 are moved integrally as described above, and their relative positional relationship is unchanged. In particular, the distances among the X-ray tube 3, the X-ray diaphragm 4 and the X-ray detector 5 in the direction orthogonal to the longitudinal direction 2a and the short direction 2b are unchanged.

  Therefore, once the form (shape and size) of the opening of the X-ray stop 4 is determined, the form of the X-ray passing region F formed by this opening is uniquely obtained by simple calculation using a trigonometric function or the like. In addition, a region (irradiation field) where X-rays are projected onto the detection surface of the X-ray detector 5 can be uniquely determined. In step S6, at least the length in the longitudinal direction 2a is calculated as an X-ray detection region for the X-ray irradiation field on the detection surface of the X-ray detector 5.

[Setting of shooting range: S7 to S10]
Subsequently, the user uses the user interface 16 to set the shooting range of the shot image, that is, the shooting start position and the shooting end position (S7, S9). At this time, the X-ray diagnostic apparatus 1 operates to acquire a fluoroscopic image including an imaging start position and an imaging end position (S8, S10).

  The setting of the shooting range will be described with reference to FIG. First, the arithmetic control unit 11 controls the X-ray control unit 12 to reduce the exposure dose to the X-ray tube 3 as a predetermined intensity (intensity for obtaining a fluoroscopic image; intensity lower than that for obtaining a captured image). X-rays are preferably generated. This X-ray forms the fluoroscopic image irradiation field in step S 4, and is detected by the X-ray detector 5 through the subject P on the bed 2. The X-ray detector 5 outputs detection data that is a detection result of the transmitted X-rays to the DR device 15. The DR device 15 forms a fluoroscopic image (image data thereof) based on the detection data. The arithmetic control unit 11 displays the fluoroscopic image on the display unit 17.

  A fluoroscopic image T shown in FIG. 4A represents a fluoroscopic image in a range from the vicinity of the abdomen of the subject P to the toes. The range of the fluoroscopic image formed at one time by the DR device 15 corresponds to the range of the irradiation field for acquiring the fluoroscopic image in step S4, and the partial fluoroscopic image T1 shown in FIG. This is the range of the partial perspective image T2 shown in B). Here, the length α in the longitudinal direction 2a of the partially transparent images T1 and T2 corresponds to the length in the longitudinal direction 2a calculated in step S6.

(Shooting start position setting and fluoroscopic image acquisition: S7, S8)
The user displays various fluoroscopic images (partial fluoroscopic images) of the subject P by moving the moving unit 6 in the longitudinal direction 2a using the user interface 16 and observes the subject P as an appropriate imaging start position. The position of the specimen P (the position in the fluoroscopic image) is specified. Then, by performing a predetermined operation, this specific position is set as a shooting start position.

  The setting of the shooting start position will be described more specifically with reference to FIG. The user operates the user interface 16 to display a partial perspective image T1 shown in FIG. For example, when the “shooting start position setting switch” is operated (clicking with the mouse, pressing a button on the control panel, etc.), the arithmetic control unit 11 obtains information indicating the position of the most abdomen side of the partial fluoroscopic image T1, The information indicating the shooting start position S is stored (S7).

  The information indicating the shooting start position S (shooting start position information) includes, for example, information indicating the position Ta1 of the moving unit 6 when the shooting start position setting switch is operated (perspective image acquisition position information) and step S5. On the basis of the aperture opening information obtained in this way, it can be obtained by executing the same arithmetic processing as the simple calculation using the trigonometric function described above. The imaging start position information is expressed as, for example, a coordinate value at coordinates defined in advance in the longitudinal direction 2a.

  Here, the fluoroscopic image acquisition position information can be acquired by the calculation control unit 11 itself storing the control contents when the drive control unit 14 is controlled, or the drive that drives the moving unit 6. The calculation control unit 11 may be configured to acquire from the control unit 14, or the position of the moving unit 6 (for example, the position of the X-ray tube 3) is directly detected by a sensor that detects the position of the moving unit 6. The calculation control unit 11 can also obtain the detection result.

  Note that the calculation of the imaging start position information is not limited to the method using the fluoroscopic image acquisition position information and the aperture opening information. For example, the imaging start position information can be obtained based on the fluoroscopic image acquisition position information and the X-ray detection area acquired in step S6. As an example, information on the length α in the longitudinal direction 2a included in the X-ray detection area is used, and α / 2 from the position indicated by the fluoroscopic image acquisition position information (in the coordinates in the predefined longitudinal direction 2a). The position displaced in the “+” direction or the “−” direction) may be obtained and used as the coordinates of the imaging start position S.

  Further, the arithmetic control unit 11 acquires and stores the partial fluoroscopic image T1 when the shooting start position setting switch is operated (S8). At this time, the image data of the display image of the partial fluoroscopic image T1 can be stored, and X-rays can be generated in the X-ray tube 3 in response to the switch operation, and the detection data thereof. The image data of the partial fluoroscopic image T1 formed by the DR device 15 based on the above can also be stored.

(Setting of photographing end position and acquisition of fluoroscopic image: S9, S10)
Next, setting of the photographing end position will be described with reference to FIG. The user moves the moving unit 6 in the longitudinal direction 2a using the user interface 16, and displays the partial fluoroscopic image T2 of the fluoroscopic image T shown in FIG. Then, when a predetermined operation (for example, an operation of the “shooting end position setting switch”) is performed, the arithmetic control unit 11 indicates information indicating the position of the most toe side of the partial fluoroscopic image T2 as the shooting end position E. It is obtained and stored as information (photographing end position information; coordinate values defined in the longitudinal direction 2a) (S9).

  For example, as in the case of the shooting start position information, the processing for obtaining the shooting end position information includes fluoroscopic image acquisition position information indicating the position Ta2 of the moving unit 6 when the shooting end position setting switch is operated, and the aperture opening degree. Based on the information, a simple calculation using the above-described trigonometric function or the like is executed (the calculation may be performed based on the fluoroscopic image acquisition position information and the X-ray detection region).

  Further, the arithmetic control unit 11 acquires and stores a partial fluoroscopic image T2 of the fluoroscopic image T when the photographing end position setting switch is operated (S10). This process can be performed, for example, similarly to step S8.

[Display of fluoroscopic image: S11]
Next, the arithmetic control unit 11 causes the display unit 17 to display a fluoroscopic image obtained by pasting the partial fluoroscopic image T1 acquired in step S8 and the partial fluoroscopic image T2 acquired in step S10 ( S11).

  The pasting process of the partial perspective images T1 and T2 will be described with reference to FIG. It is assumed that the partial perspective images T1 and T2 overlap each other by the length Δα in the longitudinal direction 2a. The length Δα of the overlapping area can be easily calculated based on, for example, the perspective image acquisition position information (coordinate values) of the partial perspective images T1 and T2 and the length α in the longitudinal direction 2a.

  In addition, the central position in the longitudinal direction 2a of this overlapping region is represented by the symbol TM. The coordinate value of the central position TM in the longitudinal direction 2a can be easily obtained as, for example, the central coordinate value of the coordinate values shown in the perspective image acquisition position information of the partial perspective images T1 and T2.

  The arithmetic control unit 11 extracts an image from the photographing start position S to the central position TM for the partial fluoroscopic image T1, and extracts an image from the central position TM to the photographing end position E for the partial fluoroscopic image T2. Then, the extracted images are displayed on the display unit 17 together with the coordinates of the center position TM. Thereby, as shown in FIG. 5, a fluoroscopic image U corresponding to the range (shooting range) from the shooting start position S to the shooting end position E is displayed. The fluoroscopic image U is desirably displayed in a state where the display density is slightly reduced.

[Shooting area setting: S12]
Subsequently, the shooting region (shooting position of each shot image for performing long shooting in the shooting range (range from the shooting start position S to the shooting end position E) set in steps S7 and S9; (Position at 2a) is set and stored (S12). Here, the shooting area means a shooting range of each of a plurality of shot images acquired in the long shooting.

  The setting mode of the shooting area will be described in more detail. The first setting mode preferentially sets the length d in the longitudinal direction 2a of the imaging region. At this time, a preset value of the length d may be automatically set, or the user may set the length d manually. An example of the latter case will be described. For a predetermined setting screen displayed on the display unit 17, the length d (for example, 20 to 50 mm) in the longitudinal direction 2a of each imaging region can be manually set. . The operation mode at this time includes a configuration in which a desired numerical value is input with a keyboard, a configuration in which a desired numerical value is selectively selected from a plurality of numerical values presented in a selectable manner (such as a pull-down menu or a button), and the like. It is possible to employ any configuration for setting D manually.

  Note that the length d is desirably (sufficiently) smaller than the length of the imaging region in the short direction 2b. The length d is desirably (sufficiently) smaller than the length α of the perspective images T1 and T2. These conditions regarding the length d are the same in the second setting mode.

  Here, the length in the longitudinal direction 2a of each imaging region is constant, but this is not necessary in the present invention, and it is possible to set imaging regions having different lengths in the longitudinal direction 2a.

  When the length d of the shooting area is set, the arithmetic control unit 11 sets the length D in the longitudinal direction 2a of the shooting range set in steps S7 and S9 (D = α + α−Δα in FIG. 4). The quotient M is obtained by dividing by the length d of each imaging region. Then, as shown in FIG. 6, the number N (N> M) of images to be photographed is calculated so that adjacent photographing regions hi, h (i + 1) have an overlapping region hi (i + 1) having a predetermined width Δd, and the photographing region hi The position (coordinate value) in the longitudinal direction 2a, that is, the position (imaging position) of the moving unit 6 corresponding to the imaging area hi is determined (i = 1 to N−1). At this time, it is desirable to make the width Δd of the overlapping region hi (i + 1) as small as possible. If the quotient M is not an integer, for example, the value of a Gaussian symbol [D / d] of D / d is obtained, and this value [D / d] is used as in the case where the quotient M is an integer. Thus, the number N of shots can be obtained.

  Here, the number of shots N and the width Δd of the overlapping area hi may be set so that the position on the foot side of the last (Nth) shooting area hN matches the shooting end position E. it can. Further, it is also possible to configure so that the position on the toe side of the photographing area hN coincides with the photographing end position E by adjusting the length of the photographing area hN in the longitudinal direction 2a. Further, the position on the foot side of the imaging region hN may be arranged on the foot side with respect to the imaging end position E.

  On the other hand, the second setting mode of the shooting area is to preferentially set the number N of shot images. The setting method can employ | adopt suitably the structure set automatically or manually like the 1st setting aspect. Moreover, also when setting manually, it can comprise similarly to the 1st setting aspect.

  When the number N of shots is set, the arithmetic control unit 11 divides the length D of the shooting range by the number N of shots, and based on the value of the quotient, the calculation control unit 11 sets the predetermined width Δd. The length d in the longitudinal direction 2a of each shooting area hi is determined and the shooting position thereof is determined so as to have the overlapping area hi (i + 1).

  In the first and second setting modes, instead of determining the shooting position of each shooting area hi, the displacement of the adjacent shooting areas hi, h (i + 1) (the moving distance of the moving unit 6) is determined. May be. In this case, using this moving distance, the shooting position can be determined in order from the first shooting area h1.

[Acquisition of Captured Image: S13 to S18]
When the shooting position of each shooting area hi is determined, the arithmetic control unit 11 controls the aperture control unit 13 to form an irradiation field corresponding to the length d of each shooting area hi obtained in step S12. Thus, the aperture blades 41 to 44 of the X-ray aperture 4 are driven to form an opening (S13).

  The opening formed in step S13 is, for example, an opening in which the irradiation field (X-ray detection area) on the detection surface of the X-ray detector 5 has a length d. The X-ray detection area and the X-ray diaphragm It can be obtained from the correspondence relationship (described above) with the shape of the four openings.

  Subsequently, the arithmetic control unit 11 controls the drive control unit 14 to move the moving unit 6 to the shooting position of the first shooting area h1 (S14).

  When the user operates the user interface 16 to request imaging (S15), the arithmetic control unit 11 controls the X-ray control unit 12 to generate X-rays having a predetermined intensity on the X-ray tube 3. This X-ray for photographing generally has a greater intensity than the X-ray for obtaining a fluoroscopic image.

  X-rays generated by the X-ray tube 3 pass through the portion of the subject P corresponding to the imaging region h1 through the opening of the X-ray diaphragm 4 formed in step S13. The X-ray detector 5 detects this transmitted X-ray and outputs detection data. The DR device 15 forms a photographic image H1 (image data) corresponding to the photographic region h1 based on the detection data (S16).

  The arithmetic control unit 11 displays the photographed image H1 superimposed on the fluoroscopic image U so that the photographing position of the photographing region h1 matches the corresponding position of the fluoroscopic image U (the position having the same coordinate value as the photographing position) (S17). ). FIG. 7 illustrates an example of a display mode of the captured image H1 displayed so as to be superimposed on the fluoroscopic image U.

  Here, the user can determine whether the captured image H1 is effective in diagnosis or the like, for example, by observing the captured image H1 and whether the contrast agent has reached the imaging region h1. If it is not valid, it is possible to acquire a valid image by performing imaging again in the imaging area h1.

  When shooting in the shooting area h1 is completed, the user operates the user interface 16 to move the moving unit 6 to the shooting position in the next shooting area h2 and obtain a shot image H2 (S18; N, S14, S15, S16). The arithmetic control unit 11 displays the photographed image H2 superimposed on the fluoroscopic image U based on the photographing position of the photographing region h2 (S17). At this time, the overlapping area between the imaging area h1 and the imaging area h2 can be bonded in the same manner as the overlapping area between the perspective images T1 and T2.

  Such a photographing operation is repeated. FIG. 8 shows an example of a display image when this shooting operation is repeatedly executed up to the i-th shooting area hi. The figure shows a state in which the captured images H1 to Hi in the respective capturing areas h1 to hi are sequentially pasted and displayed superimposed on the fluoroscopic image U.

  When the same shooting operation is repeated up to the last (Nth) shooting area hN (S18; Y), the long shooting is ended. FIG. 9 shows an example of a display image obtained by such long shooting. The photographed image H shown in the figure is obtained by pasting the photographed images H1 to HN, and is displayed superimposed on a fluoroscopic image U (not shown) (see FIGS. 7 and 8).

[Action / Effect]
The operation and effect of the X-ray diagnostic apparatus 1 as described above will be described. The X-ray diagnostic apparatus 1 has the same hardware configuration as that of the prior art. In particular, it includes a bed 2, an X-ray tube 3, an X-ray diaphragm 4, an X-ray detector 5, a drive control unit 14, a DR device 15, a user interface 16, and the like. The arithmetic control unit 11 realizes the following long photographing by performing predetermined arithmetic processing and controlling each part of the apparatus.

  The X-ray diaphragm 4 is formed by switching between an irradiation field for acquiring a fluoroscopic image and an irradiation field for acquiring a captured image under the control of the arithmetic control unit 11. Here, the irradiation field for acquiring the captured image is set so that the length of the longitudinal direction (the body axis direction of the subject P) 2a of the bed 2 is shorter than the irradiation field for acquiring the fluoroscopic image.

  The drive control unit 14 relatively moves the moving unit 6 (X-ray tube 3, X-ray diaphragm 4, X-ray detector 5; video system) and the bed 2 in the longitudinal direction 2a. When acquiring the captured image, that is, when the subject P is irradiated with X-rays from the irradiation field for acquiring the captured image, the drive control unit 14 lengthens the region of the subject based on the control of the arithmetic control unit 11. Change along direction 2a. That is, the drive control unit 14 operates to sequentially move the moving unit 6 and the bed 2 sequentially so that X-rays in the irradiation field are sequentially irradiated onto a plurality of imaging regions.

  The DR apparatus 15 irradiates the subject P with X-rays in the irradiation field for obtaining a fluoroscopic image and outputs a fluoroscopic image of the predetermined part of the subject P based on the detection data output from the X-ray detector 5. Data). The fluoroscopic image of the predetermined part is a fluoroscopic image including (at least) an image including a shooting start position and a shooting end position of the captured image.

  In addition, the DR device 15 irradiates the X-ray of the irradiation field for acquiring the captured image with respect to each of the plurality of imaging regions sequentially changed by the drive control unit 14 and outputs the X-ray detector 5. Based on the detected data, a captured image (image data) of the imaging region is formed.

  The arithmetic control unit 11 first causes the display unit 17 to display a fluoroscopic image of the predetermined part. Further, the arithmetic control unit 11 has a positional relationship between the captured image and the fluoroscopic image with respect to the sequentially acquired captured images, that is, an imaging region (imaging position) of the captured image with respect to the predetermined portion from which the fluoroscopic image is acquired. Based on the positional relationship, the captured image is displayed so as to be superimposed on the fluoroscopic image. This positional relationship can be associated by searching for a coordinate value on the projection image corresponding to the coordinate value of the shooting region (shooting position) of the shot image.

  According to such an X-ray diagnostic apparatus 1, when taking a long image, it operates so as to sequentially superimpose and display the captured image on the previously acquired fluoroscopic image. The position of the captured image can be easily grasped, and the position of each photographed image can be easily grasped.

  In addition, when performing long imaging using a contrast agent, it is possible to easily determine whether the contrast agent has reached the imaging region by checking the state of the captured image. When the contrast agent has arrived, the captured image may be used as a captured image in the imaging region. On the other hand, if the contrast agent has not reached, the captured image in the imaging region may be acquired again to check whether the contrast agent has reached. In this way, by performing imaging while grasping the arrival state of the contrast agent, it is possible to acquire suitable captured images for each imaging region. Note that the confirmation of the state of the captured image is not limited to the case of using a contrast agent, and can be applied in any imaging mode in which the state of the captured image changes with time. .

  Further, the X-ray diagnostic apparatus 1 forms a substantially rectangular irradiation field whose length in the longitudinal direction 2a is shorter than the length in the short direction 2b as an irradiation field for taking a captured image, and corresponds to this irradiation field. A captured image having a substantially rectangular shape, that is, a strip-like shape having a longer length in the short direction 2b than in the longitudinal direction 2a is formed. Accordingly, the difference between the imaging positions of adjacent imaging areas (distance in the longitudinal direction 2a), that is, the displacement when moving from one imaging area to the next imaging area becomes small, so the position of the subject P in the body thickness direction The X-ray imaging position shift based on the difference is reduced. Accordingly, it is possible to prevent a decrease in the accuracy of pasting of photographed images due to this image formation position shift, and it is possible to perform the pasting of adjacent photographed images with good accuracy.

  Furthermore, by applying such a comparatively small imaging region, scattered radiation caused by the interaction between the subject P and X-rays can be reduced, and bonding due to density unevenness in the bonded portion of the captured image It is possible to prevent a decrease in accuracy.

  The X-ray diagnostic apparatus 1 can automatically set a plurality of imaging regions in long imaging. At this time, the imaging area can be set so that the length in the longitudinal direction 2a of the overlapping area of the adjacent imaging areas becomes the minimum length (about) necessary for the bonding process. With this configuration, it is possible to reduce unnecessary exposure of the subject P in long imaging.

  Further, according to the X-ray diagnostic apparatus 1, it is possible to sequentially acquire captured images in each automatically set imaging region by simply performing a simple operation using the user interface 16.

[Modification]
The configuration detailed above is merely a specific example for suitably carrying out the present invention. Therefore, arbitrary modifications within the scope of the present invention can be made as appropriate.

  In the embodiment described above, two fluoroscopic images, a fluoroscopic image T1 including the photographing start position S and a fluoroscopic image T2 including the photographing end position E, are acquired and bonded together, thereby superimposing the captured images H1 to HN. Although it is configured to form the displayed fluoroscopic image U, the method of forming the fluoroscopic image for superimposed display is not limited to this.

  Even if the imaging range for performing long imaging is wide and the aperture formed by the X-ray diaphragm 4 is maximized, as shown in FIG. 10A, for example, a fluoroscopic image T1 ′ including an imaging start position and an imaging end position In some cases, there is a gap between the image and the fluoroscopic image T2 ′ including the. In that case, as shown in FIG. 10B, a fluoroscopic image T3 ′ that fills the interval between the fluoroscopic images T1 ′ and T2 ′ may be acquired. At this time, the fluoroscopic image U on which the captured image is superimposed and displayed can be formed by pasting the fluoroscopic image T1 ′ and the fluoroscopic image T3 ′ together with the fluoroscopic image T3 ′ and the fluoroscopic image T2 ′ ( The bonding process is the same as in the above embodiment.)

  In FIG. 10, the interval between the fluoroscopic image T1 ′ including the photographing start position and the fluoroscopic image T2 ′ including the photographing end position is filled with one fluoroscopic image T3 ′. If the interval is large, a sufficient number of fluoroscopic images may be formed to fill the interval. The position of the added fluoroscopic image can be easily obtained based on the positions of the fluoroscopic images T1 ′ and T2 ′ (for example, it can be obtained in the same manner as the imaging region setting method in the above embodiment).

  In the above embodiment, when performing long imaging using a contrast agent, the user determines whether or not the contrast agent has reached by visually checking the captured image. This determination is automatically performed. Can be configured to do.

  For this purpose, for example, the arithmetic processing unit 11 analyzes the pixel value of each pixel of the acquired captured image (step S16 in FIG. 3) and determines whether there is a pixel having a pixel value in a predetermined range. This predetermined range of information can be acquired by measuring in advance the pixel value when the region where the contrast agent has reached is imaged.

  When it is determined that there is no pixel having a pixel value within a predetermined range, the arithmetic control unit 11 performs, for example, a message indicating that the contrast agent has not reached the imaging region or imaging in the imaging region again. The display unit 17 is displayed with a message prompting the user to perform the control, or the button on the control panel (operation unit 18) for requesting photographing is blinked.

  On the other hand, when it is determined that there is a pixel having a pixel value within a predetermined range, this captured image is adopted as a captured image of the imaging region.

  Even if it is determined that there is a pixel with a pixel value within a predetermined range, if the area occupied by such a pixel is small, or the pixel value of any pixel on the downstream side of the blood flow is included in the predetermined range. If not, it is desirable to perform an operation for prompting another shooting.

  Further, by configuring so as to automatically determine whether or not the contrast medium has arrived, it is possible to automate long imaging. For example, when it is determined that the contrast agent has not reached, the imaging region is imaged again after a predetermined time has elapsed, and when it is determined that the contrast agent has reached, the moving unit 6 is moved to the next position. It is possible to automatically perform long shooting by moving the camera to the shooting area automatically.

It is a schematic block diagram showing an example of the whole structure of suitable embodiment of the X-ray diagnostic apparatus concerning this invention. 1 is a schematic perspective view showing an example of the configuration of an X-ray diaphragm of a preferred embodiment of an X-ray diagnostic apparatus according to the present invention. It is a flowchart showing an example of the usage pattern of long imaging | photography by suitable embodiment of the X-ray diagnostic apparatus which concerns on this invention. It is a schematic explanatory drawing for demonstrating the formation process of the fluoroscopic image in the long imaging | photography by preferable embodiment of the X-ray diagnostic apparatus which concerns on this invention. It is the schematic showing an example of the fluoroscopic image displayed in the long imaging | photography by preferable embodiment of the X-ray diagnostic apparatus which concerns on this invention. It is a schematic explanatory drawing for demonstrating the setting process of the imaging | photography area | region in long imaging | photography by preferable embodiment of the X-ray diagnostic apparatus which concerns on this invention. It is the schematic showing an example of the display aspect of the fluoroscopic image and picked-up image in long imaging | photography by suitable embodiment of the X-ray diagnostic apparatus which concerns on this invention. It is the schematic showing an example of the display aspect of the fluoroscopic image and picked-up image in long imaging | photography by suitable embodiment of the X-ray diagnostic apparatus which concerns on this invention. It is the schematic showing an example of the display aspect of the fluoroscopic image and picked-up image in long imaging | photography by suitable embodiment of the X-ray diagnostic apparatus which concerns on this invention. It is a schematic explanatory drawing for demonstrating the formation process of the fluoroscopic image in the long imaging | photography by the modification of suitable embodiment of the X-ray diagnostic apparatus which concerns on this invention. It is a schematic perspective view showing an example of the external appearance structure of the conventional X-ray diagnostic apparatus. It is a schematic explanatory drawing for demonstrating the problem in the long imaging | photography by the conventional X-ray diagnostic apparatus. It is a schematic explanatory drawing for demonstrating the problem in the long imaging | photography by the conventional X-ray diagnostic apparatus. It is a schematic explanatory drawing for demonstrating the problem in the long imaging | photography by the conventional X-ray diagnostic apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 X-ray diagnostic apparatus 2 Bed 3 X-ray tube 4 X-ray diaphragm 41, 42, 43, 44 Diaphragm blade 5 X-ray detector 6 Moving part 11 Computation control part 12 X-ray control part 13 Diaphragm control part 14 Drive control part 15 DR (Digital Radiography) device 16 User interface 17 Display unit 18 Operation unit 2a Longitudinal direction (body axis direction)
2b Short direction P Subject T, T1, T2, U Fluoroscopic image S Imaging start position E Imaging end position h1 to hN Imaging area H1 to HN Photographed image

Claims (10)

A sleeper,
X-ray generation means for generating X-rays;
An irradiation field forming means for forming the generated X-ray irradiation field;
X-ray detection means that is arranged at a position facing the X-ray diaphragm across the bed, detects X-rays transmitted through the subject placed on the bed, and outputs detection data;
Drive means for relatively moving the bed, the X-ray generation means, the irradiation field forming means, and the X-ray detection means along the body axis direction of the subject;
Image forming means for forming an image representing an internal form of the subject based on the output detection data;
Display means;
Display control means for displaying the formed image on the display means;
An X-ray diagnostic apparatus comprising:
The irradiation field forming means switches between the first irradiation field of the X-rays and the second irradiation field whose length in the body axis direction is shorter than the first irradiation field,
The drive means changes the region of the subject irradiated with X-rays of the second irradiation field along the body axis direction by the relative movement,
The image forming unit includes:
Forming a fluoroscopic image of a predetermined part of the subject based on the detection data output when the X-rays of the first irradiation field are irradiated;
For each of the regions of the subject that are changed by the driving means, based on the detection data output when the region is irradiated with X-rays of the second irradiation field, a captured image of the region Form the
The display control means includes
While displaying the fluoroscopic image of the predetermined part on the display means,
For each part of the subject, based on the positional relationship with respect to the predetermined part, the captured image of the part is displayed over the fluoroscopic image.
X-ray diagnostic apparatus characterized by the above. The irradiation field forming means forms, as the second irradiation field, a substantially rectangular irradiation field whose length in the body axis direction is shorter than the length in the direction orthogonal to the body axis direction,
The image forming unit forms a substantially rectangular photographed image corresponding to the substantially rectangular irradiation field as a photographed image of each part of the subject.
The X-ray diagnostic apparatus according to claim 1. A calculation unit for obtaining a shooting position of the shot image based on a length of the irradiation field formed by the irradiation field forming unit in the body axis direction and a length of the predetermined part in the body axis direction;
The drive means performs the change of the part of the subject irradiated with X-rays of the second irradiation field based on the obtained imaging position.
The X-ray diagnostic apparatus according to claim 1. Based on the number of captured images of the captured image and the length of the predetermined part in the body axis direction, the image processing apparatus further includes a calculation unit that obtains the capturing position of the captured image,
The drive means performs the change of the part of the subject irradiated with X-rays of the second irradiation field based on the obtained imaging position.
The X-ray diagnostic apparatus according to claim 1. The calculation means obtains the shooting position of the shot image so that a part of each of the adjacent shot images overlaps each other,
The X-ray diagnostic apparatus according to claim 3 or 4, wherein The drive means changes the partial region of the predetermined part irradiated with X-rays of the first irradiation field along the body axis direction by the relative movement,
For each of the changed partial areas, the image forming unit is configured to detect the partial areas based on the detection data output when the partial areas are irradiated with X-rays of the first irradiation field. Forming a perspective image,
The display control means performs the display of the fluoroscopic image of the predetermined portion by causing the display means to display the formed fluoroscopic image for each of the partial areas based on the positional relationship of the partial areas.
The X-ray diagnostic apparatus according to claim 1. Further comprising an operating means,
The drive means performs the change of the part of the subject irradiated with the X-ray in response to the operation means being operated.
The X-ray diagnostic apparatus according to claim 1. A sleeper,
X-ray generation means for generating X-rays;
An irradiation field forming means for forming the generated X-ray irradiation field;
X-ray detection means that is arranged at a position facing the X-ray diaphragm across the bed, detects X-rays transmitted through the subject placed on the bed, and outputs detection data;
Drive means for relatively moving the bed, the X-ray generation means, the irradiation field forming means, and the X-ray detection means along the body axis direction of the subject;
Image forming means for forming an image representing an internal form of the subject based on the output detection data;
Display means;
Control means for performing operation control by switching between a fluoroscopic image acquisition operation for acquiring a fluoroscopic image of the subject and a captured image acquisition operation for acquiring a captured image of the subject;
An X-ray diagnostic apparatus comprising:
The control means includes
During the fluoroscopic image acquisition operation, the irradiation field forming unit is controlled to form a first irradiation field, and detection data corresponding to the first irradiation field is output to the X-ray detection unit and the detection is performed. Displaying the fluoroscopic image formed by the image forming unit based on the data on the display unit;
During the captured image acquisition operation, the irradiation field forming unit is controlled to form a second irradiation field whose length in the body axis direction is shorter than the first irradiation field, and the driving unit is controlled to The portion of the subject irradiated with the X-rays of the second irradiation field is changed, detection data corresponding to each of the portion of the subject is output to the X-ray detection means, and the portion of the subject A photographed image formed by the image forming unit based on detection data corresponding to each of the display data is superimposed on the displayed fluoroscopic image based on a positional relationship between the part and the fluoroscopic image.
X-ray diagnostic apparatus characterized by the above. A sleeper,
X-ray generation means for generating X-rays;
An irradiation field forming means for forming the generated X-ray irradiation field;
X-ray detection means that is arranged at a position facing the X-ray diaphragm across the bed, detects X-rays transmitted through the subject placed on the bed, and outputs detection data;
Drive means for relatively moving the bed, the X-ray generation means, the irradiation field forming means, and the X-ray detection means along the body axis direction of the subject;
Image forming means for forming an image representing an internal form of the subject based on the output detection data;
Display means;
And a control method for an X-ray diagnostic apparatus that performs a fluoroscopic image acquisition operation for acquiring a fluoroscopic image of the subject and a captured image acquisition operation for acquiring a captured image of the subject. ,
During the fluoroscopic image acquisition operation,
Causing the irradiation field forming means to form a first irradiation field;
Outputting detection data corresponding to the first irradiation field to the X-ray detection means;
Causing the image forming means to form a fluoroscopic image based on the detection data;
Displaying the formed fluoroscopic image on the display means;
And execute
During the captured image acquisition operation,
Causing the irradiation field forming means to form a second irradiation field having a length in the body axis direction shorter than the first irradiation field;
Changing the portion of the subject irradiated with X-rays of the second irradiation field to the driving means;
Outputting detection data corresponding to each part of the subject to the X-ray detection means;
Causing the image forming means to form a captured image based on detection data corresponding to each part of the subject; and
Displaying the formed captured image superimposed on the displayed fluoroscopic image based on the positional relationship between the part and the fluoroscopic image;
To execute,
A control method for an X-ray diagnostic apparatus. A sleeper,
X-ray generation means for generating X-rays;
An irradiation field forming means for forming the generated X-ray irradiation field;
X-ray detection means that is arranged at a position facing the X-ray diaphragm across the bed, detects X-rays transmitted through the subject placed on the bed, and outputs detection data;
Drive means for relatively moving the bed, the X-ray generation means, the irradiation field forming means, and the X-ray detection means along the body axis direction of the subject;
Image forming means for forming an image representing an internal form of the subject based on the output detection data;
Display means;
A program for controlling an X-ray diagnostic apparatus that performs a fluoroscopic image acquisition operation for acquiring a fluoroscopic image of the subject and a captured image acquisition operation for acquiring a captured image of the subject. And
During the fluoroscopic image acquisition operation,
Causing the irradiation field forming means to form a first irradiation field;
Outputting detection data corresponding to the first irradiation field to the X-ray detection means;
Causing the image forming means to form a fluoroscopic image based on the detection data;
Displaying the formed fluoroscopic image on the display means;
And execute
During the captured image acquisition operation,
Causing the irradiation field forming means to form a second irradiation field having a length in the body axis direction shorter than the first irradiation field;
Changing the portion of the subject irradiated with X-rays of the second irradiation field to the driving means;
Outputting detection data corresponding to each part of the subject to the X-ray detection means;
Causing the image forming means to form a captured image based on detection data corresponding to each part of the subject; and
Displaying the formed captured image superimposed on the displayed fluoroscopic image based on the positional relationship between the part and the fluoroscopic image;
To execute,
A program for controlling an X-ray diagnostic apparatus.

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