JP2014104140A - X-ray diagnostic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray diagnostic apparatus capable of displaying information related to a three-dimensional posture of a medical instrument being operated by an operator inside the body of a subject during an intravascular operation, etc.SOLUTION: An X-ray diagnostic apparatus 1 includes: a C arm; an X-ray tube arranged at one end of the C arm and exposing a subject to X-rays; an X-ray detector arranged at the other end of the C arm to face the X-ray tube and detecting the X-rays; first and second fluoroscopic image data acquisition units 78, 79 for performing X-ray imaging at respective view points including at least the first view point and the second view point by rotating the C arm, and acquiring first and second fluoroscopic image data; a two-dimensional geometric conversion processing unit 74 for performing image conversion processing with respect to the second fluoroscopic image data; a motion vector calculation unit 75 for calculating a motion vector between the first fluoroscopic image and the second fluoroscopic image after the image conversion processing; and a display device 39 for displaying an image corresponding to the motion vector during the displaying of continuous fluoroscopic images.

Description

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

  An X-ray diagnostic apparatus is an image apparatus that displays the intensity of X-rays transmitted through the body of a subject as a grayscale image, and there are various types depending on purposes such as diagnosis and treatment. There are roughly two methods for visualizing a transmitted X-ray image.

  These two methods are a method using fluoroscopy and a method using photographing. An X-ray diagnostic apparatus to which a technique using fluoroscopy is applied can display collected X-ray images (fluoroscopic images) on a television monitor in real time, and is excellent in immediacy. On the other hand, in an X-ray diagnostic apparatus to which a technique using imaging is applied, it is possible to provide an X-ray image captured on a film by intense X-ray irradiation with sharpness and high spatial resolution.

  In such an X-ray diagnostic apparatus capable of fluoroscopy and imaging, DA (digital angiography) imaging can be performed while rotating the C-arm. In addition, DA imaging using an X-ray diagnostic apparatus is used as an apparatus that supports treatment using a catheter (IVR; Interventional Radiology), for example. Specifically, DA imaging by an X-ray diagnostic apparatus is used in endovascular treatment or intravascular surgery performed by inserting a medical instrument such as a catheter into a blood vessel.

  The surgeon (such as a doctor) can determine what three-dimensional posture (three-dimensional) the medical instrument such as a catheter, wire, or stent operated by the surgeon is inside the patient (subject) during intravascular surgery. It is necessary to visually check whether the position is taken. Therefore, a plurality of methods are considered as a method for visually recognizing the three-dimensional posture of the medical instrument.

  As one of a plurality of methods, a technique of stereo observation using an X-ray diagnostic apparatus is known. In this technique, a pair of left and right images obtained by X-ray exposure from an X-ray source (stereo tube) having two X-ray focal points separated by a distance corresponding to the distance between the left and right eyes are respectively corresponding eyes. This is a technique that allows an operator to stereoscopically view a medical instrument by observing.

  In addition, an X-ray diagnostic apparatus is also known that allows a C-arm to be moved at a high speed for stereo observation, images a subject from two viewpoints, and assists an operator to perceive a three-dimensional structure in stereo observation. (See Patent Document 1).

  Further, as a method for visually recognizing a three-dimensional posture of a medical instrument, it is conceivable to image a subject using a biplane system having two sets of an X-ray tube and an X-ray flat detector.

Japanese Patent Laid-Open No. 10-33516

  According to the prior art, during an intravascular operation, the three-dimensional posture (three-dimensional position) of the medical device operated by the operator is visually confirmed by a plurality of methods. I can. For example, as described above, two methods are broadly considered, and as one eye method, a stereo observation technique using a stereo tube is known. As a second method, it is known to image a subject using a biplane system.

  However, regardless of which method is used, the exposure dose of X-rays exposed to the subject increases. In the case of the former method, the stereo tube itself is originally expensive, and is often not mounted on a conventional X-ray diagnostic apparatus. Therefore, the former method is immediately applied to an existing X-ray diagnostic apparatus. I can't. On the other hand, the latter method cannot be immediately applied to an existing X-ray diagnostic apparatus using a single plane.

  Thus, during intravascular surgery, the three-dimensional posture (three-dimensional position) of the medical instrument operated by the operator within the body of the subject simply and inexpensively while suppressing the exposure dose. There has been a problem that the surgeon cannot visually recognize the information regarding.

  In order to solve the above-described problems, the X-ray diagnostic apparatus according to the present embodiment is provided with a C arm, an X-ray tube that is provided at one end of the C arm, and exposes the X-ray to the subject, and is opposed to the X-ray tube. However, an X-ray detector that is provided at the other end of the C-arm and detects X-rays, and when a medical instrument is inserted into the subject, the C-arm is rotated to at least the first viewpoint and the second viewpoint. X-ray images are taken at each of a plurality of viewpoints including X-ray images from the first viewpoint, and X-ray images are taken from the second viewpoint in a time-sequential sequence with the first perspective image data. An acquisition means for acquiring second fluoroscopic image data to be photographed by line, an image conversion means for performing image conversion processing on the second fluoroscopic image data acquired by the acquisition means, and an image based on the first fluoroscopic image data Based on the second fluoroscopic image data after the image conversion processing by the image conversion means Difference information between the image and the image is calculated for each pixel or image region, a motion vector calculating means for calculating a motion vector, an image based on the first perspective image data, and a second after image conversion processing by the image converting means. Display means for displaying an image based on the fluoroscopic image data as a continuous fluoroscopic image continuous in time series, and displaying an image according to the motion vector calculated by the motion vector calculating means during display of the continuous fluoroscopic image; Have.

The figure which shows the structural example which shows the X-ray diagnostic apparatus of this embodiment. The figure which shows the structural example of an X-ray diagnostic apparatus provided with the X-ray detection apparatus which has a plane detector. The functional block diagram which shows the function of the X-ray CT apparatus of this embodiment. The figure which shows a mode that a C arm is moved circularly and X-ray imaging is performed from several viewpoints. The schematic diagram which shows the some fluoroscopic image acquired by the X-ray imaging from a some viewpoint. Explanatory drawing for demonstrating the outline | summary of planar projection conversion used when an image deformation | transformation is performed so that a 2nd perspective image may turn into a 1st perspective image. The figure which shows the relationship between the moving direction in which the image and point which are not contained in a reference plane move within the image before and after plane projective transformation, and the moving direction of the circular motion of the X-ray tube. The flowchart explaining the three-dimensional positional information notification process in the X-ray diagnostic apparatus of this embodiment. Explanatory drawing explaining the motion vector calculation by a motion vector calculation part. The figure which traced from the position of the base of a wire to the front-end | tip part, and plotted the magnitude | size of the motion vector.

  The X-ray diagnostic apparatus of this embodiment will be described with reference to the accompanying drawings. In the present specification, the X-ray diagnostic apparatus according to the present embodiment basically assumes that a set of an X-ray tube and an X-ray flat panel detector has one single plane system. However, the present invention is not limited to such a system, and the present invention can be applied to an X-ray diagnostic apparatus having a biplane system having two sets of an X-ray tube and an X-ray flat detector.

  Furthermore, the X-ray diagnostic apparatus of the present embodiment can implement two modes, a DA (Digital Angiography) mode and a DSA (Digital Subtraction Angiography) mode. The “DA mode” is a mode in which normal X-ray imaging is performed, and an X-ray image including a contrast medium (flow) is simply acquired and displayed and stored.

  In contrast, the “DSA mode” is an X-ray image (mask image) that does not include a contrast agent (image) and an X-ray image (contrast image or live image) that includes a contrast agent (image). This mode is capable of displaying and storing an X-ray image that captures the contrast agent or its flow more clearly by acquiring a difference image (subtraction processing).

  In the present embodiment, the basic operation and effect are not affected by shooting in any mode. That is, shooting can be performed in either the DA mode or the DSA mode.

  FIG. 1 is a diagram showing a configuration example showing an X-ray diagnostic apparatus 1 of the present embodiment.

  As shown in FIG. 1, the X-ray diagnostic apparatus 1 includes a C-arm holding device 11 and a DF (digital fluorography) device 12.

  The C-arm holding device 11 having a general C-arm structure includes an X-ray tube 21, an X-ray detection device 22, a C arm 23, a top plate (catheter table) 24, a high voltage supply device 25, and a drive mechanism 26.

  The C-arm holding device 11 is described as an overtube type in which the X-ray tube 21 is located above the top plate 24, but is an undertube type in which the X-ray tube 21 is located below the top plate 24. There may be some cases. Further, an X-ray irradiation field stop composed of a plurality of lead feathers may be provided on the X-ray emission side of the X-ray tube 21. The X-ray tube 21 is formed of silicon rubber or the like, and has a predetermined amount to prevent halation. A compensation filter for attenuating the irradiated X-rays may be provided.

  The X-ray tube 21 is provided at one end of the C-arm 23, receives high-voltage power from the high-voltage supply device 25, and moves toward a predetermined part of the subject (patient) P according to the high-voltage power condition. X-ray exposure. As a result, the X-ray tube 21 can emit imaging X-rays for imaging a predetermined part and fluoroscopic X-rays for seeing through the predetermined part.

  Specifically, in the case of imaging X-rays, the X-ray tube 21 is exposed by being controlled to a tube voltage of 80 [kV] and a tube current of 500 [mA], while in the case of fluoroscopic X-rays. The X-ray tube 21 is exposed to light by being controlled to a tube voltage of 80 [kV] and a tube current of 50 [mA].

  The X-ray detection device 22 is provided on the opposite side of the other end of the C-arm 23 and on the side where the X-ray tube 21 is provided, and detects X-rays transmitted through a required part of the patient (subject) P. The X-ray detector 22 is an I. (Image intensifier) -TV system, I. 22a and a TV camera 22b.

  I. I. 22a converts X-rays transmitted through the patient P into visible light and doubles the luminance to form sensitive projection data. The TV camera 22b converts optical projection data into an electrical signal using a CCD (charge coupled device) image sensor.

  In this way, the C arm 23 supports the X-ray tube 21 at one end and the X-ray detection device 22 at the other end, thereby detecting the X-ray tube 21 and the X-ray detection centering on the patient P. The device 22 can be placed oppositely. Further, the movement amount, movement timing, and movement speed of the C arm 23 are controlled by the drive mechanism 26.

  The top plate 24 places the patient P thereon.

  The high voltage supply device 25 supplies high voltage power to the X-ray tube 21 under the control of a DF (Digital Fluorography) device 12.

  The drive mechanism 26 moves the C arm 23 in a circular motion (moving in the direction of the LAO (left antio- obelique view) direction and RAO (right-animate oblige view)) or rotating the C-arm 23 (CRA) according to the control by the DF device 12. (Movement in the (clinical view) direction and CAU (caudal view) direction). The drive mechanism 26 controls the arc movement and rotation movement of the C arm 23, thereby realizing DA imaging for acquiring unidirectional image data and rotating DA imaging for acquiring multidirectional image data.

  In addition, the drive mechanism 26 translates the C arm 23 with respect to the body axis direction of the patient P (the Z axis direction shown in FIG. 1), or moves the C arm 23 and the top plate 24 according to control by the DF device 12. It can be erected as a unit. Further, the drive mechanism 26 moves the X-ray tube 21 and the X-ray detection device 22 in the body axis direction of the patient P and moves the C arm 23 in the body axis direction of the patient P according to the control by the DF device 12. Move straight. In addition, the drive mechanism 26 moves the top plate 24 in the vertical direction (Y-axis direction shown in FIG. 1), left-right direction (X-axis direction shown in FIG. 1), and body axis direction according to control by the DF device 12. Let

  The DF device 12 is configured based on a computer, and can communicate with a network N such as a hospital backbone LAN (Local Area Network). The DF device 12 includes an A / D (Analog to Digital) conversion circuit 31, an image generation / processing circuit 32, an image memory 33, a CPU (Central Processing Unit) 34 as a processor, an HDD (Hard Disc Drive) 35, a memory 36, The system control unit 37, the input device 38, the display device 39, the storage medium drive 40, the communication control device 41, and the speaker 42 are provided.

  The CPU 34 is interconnected to each hardware component constituting the DF device 12 via a bus 43 as a common signal transmission path.

  The A / D conversion circuit 31 converts the time-series analog signal (video signal) output from the X-ray detection device 22 into a digital signal.

  The image generation / processing circuit 32 generates image data in frame units for the digital signal of the projection data output from the A / D conversion circuit 31 under the control of the CPU 34. Further, the image generation / processing circuit 32 stores the generated frame-unit image data in the image memory 33 or the HDD 35, or the generated frame-unit image data for real-time display or the reproduction stored in the image memory 33. Image processing is performed on image data for each frame for display, and the image data after image processing is output to the CPU 34.

  Examples of image processing include enlargement / gradation / space filter processing for image data, minimum / maximum value trace processing of image data accumulated in time series, and addition processing for removing noise.

  The image memory 33 stores the image data output from the image generation / processing circuit 32 under the control of the CPU 34.

  The A / D conversion circuit 31, the image generation / processing circuit 32, and the image memory 33 can handle these as one image processing unit 60.

  The CPU 34 synthesizes the image data output from the image generation / processing circuit 32 together with character information, scales, and the like of various parameters, and outputs them as a video signal to the display device 39.

  The display device 39 is composed of a monitor, a liquid crystal display, and the like, and displays an X-ray image on the monitor based on a video signal output from the CPU 34.

  The CPU 34 executes a program stored in the memory 36 when a command is input by operating the input device 38 by an operator or the like. The CPU 34 reads the program stored in the HDD 35, the program transferred from the network N and received by the communication control device 41 and installed in the HDD 35, or the recording medium loaded in the storage medium drive 40 and installed in the HDD 35. The program thus loaded is loaded into the memory 36 and executed.

  The HDD 35 is composed of a metal disk coated or vapor-deposited with a magnetic material, and is built in a reader (not shown) so as not to be attached or detached. The HDD 35 is a storage device that stores programs installed in the DF device 12 (including OS (operating system) in addition to application programs) and collected image data.

  The memory 36 has elements such as a ROM (read only memory) and a RAM (random access memory), and stores an initial program loading (IPL), a basic input / output system (BIOS), and a work memory of the CPU 34. A storage device used for temporary storage of data.

  The system control unit 37 has a CPU and a memory (not shown). The system control unit 37 controls operations of the high voltage supply device 25 and the drive mechanism 26 of the C-arm holding device 11 in accordance with instructions from the CPU 34.

  The input device 38 includes a keyboard and a mouse that can be operated by an operator or the like, and an input signal according to the operation is sent to the CPU 34.

  The communication control device 41 performs communication control according to each standard. The communication control device 41 has a function capable of connecting to the network N through a telephone line network or the like. Thereby, the X-ray diagnostic apparatus 1 can be connected to the network N from the communication control apparatus 41.

  The speaker 42 is a member that can output sound.

  The X-ray detection device 22 is an I.D. I. Instead of the 22a and the TV camera 22b, a flat panel detector (FPD) may be provided.

  FIG. 2 is a diagram illustrating a configuration example of the X-ray diagnostic apparatus 1 including the X-ray detection apparatus 22 having a flat detector. In addition, the same code | symbol is attached | subjected about the structure similar to FIG. 1, and the description is abbreviate | omitted.

  As shown in FIG. 2, when the X-ray detection device 22 has a flat detector, the X-ray detection device 22 detects X-rays by detection elements arranged in a 2D (two dimensions) form and converts them into electrical signals. A flat detector (2D array type X-ray detector) 51 and a DAS (Data Acquisition System) 52 that collects X-ray detection data detected as an electrical signal by each detection element of the flat detector 51. Then, the DAS 52 supplies the collected X-ray detection data (raw data) to the image processing unit 61 of the DF device 12.

  The image processing unit 61 of the DF device 12 performs correction processing (pre-processing) such as logarithmic conversion processing and sensitivity correction on the raw data input from the DAS 52 of the C-arm holding device 11 to generate projection data, and the HDD 35 And so on. The CPU 34 causes the display device 45 to display an image based on the generated projection data.

  FIG. 3 is a functional block diagram showing functions of the X-ray CT apparatus 1 of the present embodiment. In this specification, a case where the present invention is applied to an X-ray diagnostic apparatus 1 including an X-ray detection apparatus 22 having a flat detector 51 and a DAS 52 as shown in FIG. 2 will be described. Of course, the present invention can also be applied to an X-ray diagnostic apparatus 1 as shown in FIG.

  As the CPU 34 (FIG. 2) of the DF apparatus 12 executes the program, the X-ray diagnostic apparatus 1 has an input receiving unit 71, an X-ray imaging execution control unit 72, a reference plane setting unit 73, as shown in FIG. 2D geometric transformation processing unit 74, motion vector calculation unit 75, 3D position determination unit 76, 3D position notification unit 77, first perspective image data acquisition unit 78, second perspective image data acquisition unit 79, continuous perspective image data Functions as the generation unit 80 and the display control unit 81 are provided.

  Note that all or some of the units illustrated in FIG. 3 may be provided as hardware in the DF device 12. 3 may be provided not only in the DF device 12 but also in the C-arm holding device 11.

  The input receiving unit 71 receives various inputs from the input device 38 when the operator operates the input device 38 of the DF device 12. In particular, the input receiving unit 71 starts an X-ray imaging process for acquiring three-dimensional position information (three-dimensional posture information) related to a medical instrument during intravascular surgery, which is controlled by the X-ray imaging execution control unit 72. The input about whether or not is accepted.

  Further, the input receiving unit 71 appropriately performs the medical instrument during the intravascular operation after the X-ray imaging process for acquiring the three-dimensional position information (three-dimensional posture information) regarding the medical instrument during the intravascular operation is started. An input as to whether or not to end the X-ray imaging process for acquiring the three-dimensional position information on the image is received.

  When the input receiving unit 71 receives an input to start X-ray imaging processing for acquiring three-dimensional position information, the X-ray imaging execution control unit 72 receives an intravascular vessel based on an instruction from the input receiving unit 71. X-ray imaging processing for acquiring three-dimensional position information related to the medical instrument being operated is started. Specifically, the X-ray imaging execution control unit 72 controls the system control unit 37 of the DF device 12 to cause the C-arm holding device 11 to execute X-ray imaging under a predetermined condition via the system control unit 37.

  In addition, when the input receiving unit 71 receives an input indicating that the X-ray imaging processing for obtaining the three-dimensional position information is to be ended, the X-ray imaging execution control unit 72 is based on an instruction from the input receiving unit 71. Then, the X-ray imaging process for obtaining the three-dimensional position information is finished. In this case as well, the X-ray imaging execution control unit 72 controls the system control unit 37 of the DF device 12 and ends X-ray imaging under a predetermined condition by the C-arm holding device 11 via the system control unit 37. .

  When the input receiving unit 71 receives an input to start X-ray imaging processing for obtaining three-dimensional position information, the reference plane setting unit 73 performs an intravascular operation based on an instruction from the input receiving unit 71 A reference plane is set as a reference for acquiring three-dimensional position information regarding the medical device inside. Then, the reference plane setting unit 73 supplies information regarding the set reference plane to the two-dimensional geometric transformation processing unit 74 and the three-dimensional position determination unit 76. The reference plane setting unit 73 can reset the reference plane as appropriate after the X-ray imaging process for acquiring the three-dimensional position information is started.

  When the X-ray imaging process for acquiring the three-dimensional position information is started by the X-ray imaging execution control unit 72, the first fluoroscopic image data acquisition unit 78 is accompanied by the execution of the X-ray imaging process. The first fluoroscopic image data acquired by the image processing unit 61 (FIG. 2) is read from the HDD 35.

  The first fluoroscopic image data is once recorded (stored) in the HDD 35 when acquired by the image processing unit 61. Therefore, the first perspective image data acquisition unit 78 acquires the first perspective image data by reading the first perspective image data from the HDD 35. The first fluoroscopic image data is image data that is captured and acquired by X-ray exposure from the first viewpoint.

  When the X-ray imaging process for acquiring the three-dimensional position information is started by the X-ray imaging execution control unit 72, the second fluoroscopic image data acquisition unit 79 is accompanied with the execution of the X-ray imaging process and the DF device 12. The second fluoroscopic image data acquired by the image processing unit 61 (FIG. 2) is read from the HDD 35.

  When the second fluoroscopic image data is acquired by the image processing unit 61, it is once recorded (stored) in the HDD 35. Therefore, the second perspective image data acquisition unit 79 acquires the second perspective image data by reading the second perspective image data from the HDD 35. Note that the second fluoroscopic image data is image data acquired and acquired by exposing X-rays from a second viewpoint different from the first viewpoint.

  The two-dimensional geometric transformation processing unit 74 acquires information on the reference plane supplied from the reference plane setting unit 73 and acquires second perspective image data supplied from the second perspective image data acquisition unit 79. The two-dimensional geometric conversion processing unit 74 performs an image conversion process on an image based on the second perspective image data photographed by the X-ray exposure from the second viewpoint while using the reference plane as a reference. . Specifically, the two-dimensional geometric transformation processing unit 74 is an image based on the first perspective image data that is captured when the image based on the second perspective image data is exposed to X-rays from the first viewpoint. An image conversion process is performed so that the image is based on the second perspective image data. The two-dimensional geometric conversion process 74 supplies the second perspective image data after the image conversion process to the motion vector calculation unit 75 and the continuous perspective image data generation unit 80.

  The motion vector calculation unit 75 acquires the first perspective image data supplied from the first perspective image data acquisition unit 78 and the second perspective image data after the image conversion process supplied from the two-dimensional geometric conversion processing unit 74. To get. The motion vector calculation unit 75 compares an image based on the first fluoroscopic image data constituting the continuous fluoroscopic image continuous in time series with an image based on the second fluoroscopic image data after the image conversion process.

  Then, the motion vector calculation unit 75 calculates difference information between two images (difference information between frames) for each pixel (or image region), and a motion vector for expressing a change in the image in a predetermined image region. Is calculated. The motion vector calculation unit 75 supplies information regarding the calculated motion vector to the three-dimensional position determination unit 76.

  The three-dimensional position determination unit 76 is based on the information on the reference plane set by the reference plane setting unit 73 and the information on the motion vector calculated by the motion vector calculation unit 75, Determine the position. That is, the three-dimensional position determination unit 76 determines whether the medical instrument during the intravascular operation is located in a region in the Y axis positive direction or in the Y axis negative direction with respect to the reference plane.

  The three-dimensional position notification unit 77 notifies the operator of the three-dimensional position of the medical instrument inserted in the blood vessel based on the determination result supplied from the three-dimensional position determination unit 76.

  The continuous perspective image data generation unit 80 acquires the first perspective image data supplied from the first perspective image data acquisition unit 78 and the second perspective after the image conversion process supplied from the two-dimensional geometric conversion processing unit 74. Get image data. Then, the continuous fluoroscopic image data generation unit 80 generates continuous fluoroscopic image data continuous in time series based on the first fluoroscopic image data acquired as appropriate and the second fluoroscopic image data after the image conversion process. The continuous perspective image data generation unit 80 supplies the generated continuous image data to the display control unit 81.

  The display control unit 81 acquires the continuous fluoroscopic image data supplied from the continuous fluoroscopic image data generation unit 80 and causes the display device 39 to display a continuous fluoroscopic image based on the continuous fluoroscopic image data. Further, the display control unit 81 causes the display device 39 to display information related to the three-dimensional position of the medical device based on the determination result in accordance with the instruction from the three-dimensional position notification unit 77.

  Next, the concept of a three-dimensional position determination method related to a medical instrument during intravascular surgery that can be executed by the X-ray diagnostic apparatus 1 of FIGS. 1 to 3 will be described.

  FIG. 4 is a diagram illustrating a state in which X-ray imaging is performed from a plurality of viewpoints by moving the C arm 23 in an arc. As shown in FIG. 4, the drive mechanism 26 moves the C arm 23 in a circular motion (moving in the LAO (left ani- mentor oblige view) direction and the RAO (right ani- ter-obligation view) direction) according to the control by the DF device 12.

  In the case of FIG. 4 (P), the C arm 23 is moved in an arc, and the X-ray tube 21 and the X-ray detection device 22 at both ends of the C arm 23 are moved to positions A and A ′, respectively. Photographing is performed on a straight line AA ′. At this time, the X-ray imaging performed on the straight line AA ′ is defined as “X-ray imaging from the first viewpoint”. Then, the projection data generated when the X-ray is exposed and imaged from the first viewpoint is defined as “first perspective image data”.

  On the other hand, in the case of FIG. 4Q, the C arm 23 is moved in a circular arc at a predetermined angle (for example, about 5 degrees), and the X-ray tube 21 and the X-ray detection device 22 at both ends of the C arm 23 are positioned. Moving from A and A ′ to positions B and B ′, X-ray imaging for the patient P is performed on a straight line BB ′. At this time, X-ray imaging performed on the straight line BB ′ is defined as “X-ray imaging from the second viewpoint”. Then, the projection data generated when the X-ray is exposed and imaged from the second viewpoint is defined as “second perspective image data”.

  A center point that is not geometrically or spatially displaced even when the C-arm 23 moves or rotates in a circular arc is defined as an “isocenter”.

  FIG. 5 is a schematic diagram showing a plurality of fluoroscopic images acquired by X-ray imaging from a plurality of viewpoints. FIG. 5P is a schematic diagram illustrating an image based on first fluoroscopic image data acquired by X-ray imaging from the first viewpoint. FIG. 5Q is a schematic diagram illustrating an image based on second perspective image data acquired by X-ray imaging from the second viewpoint.

  The solid lines in FIGS. 5 (P) and (Q) show how medical instruments such as catheters and wires operated by the operator are inserted into a predetermined blood vessel during intravascular surgery. The broken lines in FIGS. 5 (P) and 5 (Q) schematically show blood vessels through which medical instruments such as wires can pass through the operation of the operator during intravascular surgery. Note that the broken line portions in FIGS. 5 (P) and (Q) are often not visible in an actual fluoroscopic image.

  5 (P) and (Q) show a state where the blood vessel is branched into three in the middle, and a medical instrument such as a wire is inserted in the central branch blood vessel. Further, as shown in FIGS. 5 (P) and (Q), an image based on the first fluoroscopic image data acquired by X-ray imaging performed on the straight line AA ′ (FIG. 4), and a straight line B− The image based on the second fluoroscopic image data acquired by X-ray imaging performed on B ′ (FIG. 4) is not a little different because the angle at which the patient (subject) P is imaged is different.

  Here, it is considered that the image based on the second perspective image data is subjected to image deformation so as to become an image based on the first perspective image data.

  For example, if a horizontal plane (horizontal plane including an isocenter) passing through the center of the patient (subject) P is set as the reference plane, X on the line BB ′ with respect to an image or a point included in the reference plane Consider an image transformation of a line-photographed image so that it becomes an image photographed on a straight line AA ′. In other words, assuming a very thin patient P included in the reference plane, each pixel of the fluoroscopic image photographed on the straight line BB ′ is represented by each pixel of the fluoroscopic image photographed on the straight line AA ′. Pixel coordinate conversion (this is called image conversion) is performed so that the pixel is located at the same position.

  Such image conversion can be performed by, for example, planar projection conversion described later. When explaining the concept of the three-dimensional position determination method, it is assumed that there is no movement of a medical instrument such as a wire or body movement of a patient (subject) P in order to simplify the explanation.

  FIG. 6 is an explanatory diagram for explaining an outline of planar projection conversion used when image transformation is performed so that the second perspective image becomes the first perspective image.

  In FIG. 6, for example, it is assumed that a letter “G” is drawn on a reference plane surrounded by a square. In this case, a perspective image taken on the straight line AA ′ (FIG. 4) regarding the character “G” included in the reference plane is shown in FIG. 6 (P).

  Further, regarding the character “G” included in the reference plane, a perspective image taken along a straight line BB ′ (FIG. 4) is shown in FIG. 6 (Q). Since the character “G” is included in the reference plane surrounded by the square, each pixel of the fluoroscopic image photographed by the straight line BB ′ (FIG. 4) is converted into the straight line by performing the above-described plane projective transformation. An image that looks the same as the fluoroscopic image taken on A-A ′ (FIG. 4) is obtained. The image at this time is shown in FIG. In addition, the broken line in FIG. 6 (R) indicates the original circumscribed boundary of the fluoroscopic image photographed by the straight line BB ′.

  Here, when the black circle M that does not exist in the reference plane is at the center upper side of the character “G” (the Y-axis positive direction side (see FIG. 4)), from FIG. 6 (P) to (R). Consider the plane projective transformation described in Section 2.

  When the image is taken on the straight line A-A ′, as shown in FIG. 6S, the black circle M is located in the region on the right side of the character “G”. On the other hand, when the image is taken on the straight line BB ′, as shown in FIG. 6 (T), the black circle M is located in the left region of the character “G”.

  Then, when each pixel of the fluoroscopic image photographed by the straight line BB ′ is subjected to the planar projective transformation described above, as shown in FIG. 6 (U), the character “ The black circle M is converted to the left side of the character “G” together with the image region portion of “G”. That is, an image or a point that is not included in the reference plane moves in the image before and after the conversion by plane projection conversion.

  FIG. 7 is a diagram illustrating a relationship between a moving direction in which an image or a point not included in the reference plane moves in the image before and after the planar projective transformation and a moving direction of the arc motion of the X-ray tube 21.

  As described above, in FIG. 7, when the observation target is included in the reference plane, the pixel does not move by plane projective transformation. However, since images and points above and below the reference plane are not included in the reference plane, they move within the image by plane projective transformation.

  In this case, the moving direction of the image or point accompanying the plane projective transformation differs depending on whether the image or point is above or below the reference plane. For example, as shown in FIG. 7, when the movement direction in the X-axis direction accompanying the arc movement of the X-ray tube 21 is the positive direction, an image or a point that exists above the reference plane is converted into an arrow by plane projection conversion. Move in the negative direction of the X-axis represented by K. Therefore, the moving direction of the X-ray tube 21 in the X-axis direction is opposite to the moving direction of images and points existing above the reference plane.

  On the other hand, an image or a point existing below the reference plane is represented by an arrow L along with plane projective transformation when the movement direction in the X-axis direction accompanying the arc motion of the X-ray tube 21 is positive. Moved in the positive direction of the X axis. Therefore, the moving direction of the X-ray tube 21 in the X-axis direction is the same as the moving direction of images and points existing below the reference plane.

  Here, the upper side and the lower side of the reference plane are expressed as the upper side in the direction perpendicular to the reference plane (Y-axis direction) and close to the X-ray tube 21 (Y-axis positive direction), The one far from the X-ray tube 21 (Y-axis negative direction) is indicated as the lower side. In addition, as viewed from the X-ray tube 21, the front side / back side may be described.

  In the X-ray diagnostic apparatus 1 of the present embodiment, when X-ray imaging is performed from a plurality of viewpoints and a continuous fluoroscopic image is displayed, a predetermined image conversion process is performed on the fluoroscopic images that are X-rayed for each viewpoint, The property that the moving direction of the image and the point accompanying the plane projective transformation differs depending on whether the image or the point is above or below the reference plane is used.

  Thereby, the X-ray diagnostic apparatus 1 of this embodiment can extract the information regarding the three-dimensional position of a medical instrument from the two-dimensional image on a XZ plane called a fluoroscopic image. Therefore, the X-ray diagnostic apparatus 1 of this embodiment can determine the three-dimensional position related to the medical instrument during the intravascular operation based on the extracted information related to the three-dimensional position.

  Next, on the premise of the concept of the three-dimensional position determination method related to the medical instrument during the intravascular surgery described with reference to FIGS. 4 to 7, the three-dimensional position information notification process in the X-ray diagnostic apparatus 1 of the present embodiment will be described. This will be described with reference to a flowchart. In addition, FIGS. 4-7 is referred as needed.

  FIG. 8 is a flowchart for describing the three-dimensional position information notification process in the X-ray diagnostic apparatus 1 of the present embodiment.

  In step S <b> 1, the input receiving unit 71 performs an X-ray imaging process for acquiring three-dimensional position information (three-dimensional posture information) related to a medical instrument during endovascular surgery, which is controlled by the X-ray imaging execution control unit 72. Accepts input about whether to start. The input receiving unit 71 determines whether or not an input as to whether or not to start this X-ray imaging process has been received, and waits until it is determined that an input for starting this process has been received.

  In step S1, when it is determined that an input for starting X-ray imaging processing for acquiring three-dimensional position information regarding a medical instrument during endovascular surgery has been received, the input receiving unit 71 performs X-ray imaging to that effect. This is notified to the execution control unit 72 and the reference plane setting unit 73.

  In step S <b> 2, the reference plane setting unit 73 sets a reference plane serving as a reference for acquiring three-dimensional position information regarding the medical instrument during the intravascular operation in accordance with the notification and instruction from the input receiving unit 71. Specifically, the reference plane setting unit 73 sets, for example, a horizontal plane (horizontal plane including an isocenter) passing through the center of the patient (subject) P as a reference plane.

  The setting of the reference plane is not limited to such setting, and the reference plane setting unit 73 only needs to be able to determine which blood vessel the medical instrument is inserted during the intravascular operation. Any surface may be set as the reference surface.

  In addition, the reference plane setting unit 73 sets an arbitrary reference plane so that a blood vessel in which a medical instrument such as a wire is advanced and other blood vessels (blood vessels that are easily mis-branched) are present with a reference plane sandwiched in a predetermined range. It can also be set.

  As shown in FIGS. 5 (P) and 5 (Q), the fluoroscopic image exists on the XZ plane, so even if the medical instrument advances to the left and right during the intravascular operation, it can be easily moved in the X-axis direction. Can be distinguished. For this reason, the movement of the medical instrument in this case can be easily displayed on the display device 39.

  The reference plane setting unit 73 can also set a reference plane in a predetermined manner based on an anatomical positional relationship. When a predetermined reference plane is set, the X-ray diagnostic apparatus 1 determines the rotation axis and the rotation direction of the C arm 23 so as to match the reference plane.

  In step S <b> 3, the X-ray imaging execution control unit 72 starts the X-ray imaging process for acquiring the three-dimensional position information based on the notification and instruction from the input reception unit 71, so that the system of the DF device 12 is started. The control unit 37 is controlled. The X-ray imaging execution control unit 72 causes the C-arm holding device 11 to perform X-ray imaging under a predetermined condition via the system control unit 37. The X-ray imaging execution control unit 72 controls the system control unit 37 to move the C-arm 23 to the initial position, and starts X-ray imaging processing for acquiring three-dimensional position information.

  Specifically, as shown in FIGS. 4P and 4Q, the X-ray imaging execution control unit 72 performs X-ray imaging processing from a plurality of viewpoints by moving the C arm 23 in an arc. The drive mechanism 26 moves the C arm 23 in an arc according to the control by the DF device 12.

  In the case of FIG. 4 (P), the C arm 23 is moved in an arc, and the X-ray tube 21 and the X-ray detection device 22 at both ends of the C arm 23 are moved to positions A and A ′, respectively. X-ray imaging is performed on a straight line AA ′.

  On the other hand, in the case of FIG. 4Q, the C arm 23 is moved in a circular arc at a predetermined angle (for example, about 5 degrees), and the X-ray tube 21 and the X-ray detection device 22 at both ends of the C arm 23 are moved. Moving from positions A and A ′ to positions B and B ′, respectively, X-ray imaging for the patient P is performed on a straight line BB ′.

  Thereby, X-ray imaging of the first fluoroscopic image and X-ray imaging of the second fluoroscopic image are executed. Note that the X-ray diagnostic apparatus 1 of the present embodiment may capture a fluoroscopic image from three or more viewpoints.

  The first fluoroscopic image data acquisition unit 78 acquires the first fluoroscopic image acquired by the image processing unit 61 (FIG. 2) of the DF device 12 and recorded (stored) in the HDD 35 as the X-ray imaging process is executed. The first perspective image data is acquired by reading the data from the HDD 35. The first fluoroscopic image data is image data that is captured and acquired by exposure of X-rays from a first viewpoint (a viewpoint directed from position A to position A ′).

  Similarly, the second fluoroscopic image data acquisition unit 79 acquires the second fluoroscopic image data acquired by the image processing unit 61 of the DF apparatus 12 and recorded (stored) in the HDD 35 as the X-ray imaging process is executed. The second fluoroscopic image data is acquired by reading from. The second fluoroscopic image data is image data that is captured and acquired by exposure of X-rays from a second viewpoint (a viewpoint directed from position B to position B ′).

  In step S <b> 4, the two-dimensional geometric transformation processing unit 74 acquires information on the reference plane supplied from the reference plane setting unit 73 and acquires second perspective image data supplied from the second perspective image data acquisition unit 79. To do. Then, the two-dimensional geometric transformation processing unit 74 uses the first perspective imaged by exposing the X-ray from the first viewpoint to the image based on the second perspective image data while using the reference plane as a reference. Image conversion processing is performed so that an image based on the image data is obtained, and an image based on the second perspective image data is converted.

  Here, as one of image conversion processing methods performed by the two-dimensional geometric conversion processing unit 74, there is planar projective conversion. The plane projective transformation will be specifically described below.

  As shown in FIGS. 4 (P) and (Q), there are two imaging systems AA ′ and BB ′. The plane projective transformation matrix (or homography matrix) is uniquely determined from the geometric positional relationship between the two imaging systems.

  In order to simplify the description, the imaging system is approximated to a normalized imaging system with a focal length of 1. For example, a translation vector from the imaging system A-A ′ to BB ′ is t (t is a three-dimensional column vector), a rotation matrix is R (3 × 3 matrix), and a reference plane (which becomes a reference) The normal vector of the plane is n (n is a three-dimensional column vector), and the distance from the center of the X-ray tube 21 of the imaging system AA ′ to the reference plane is d.

  In this case, the planar projective transformation matrix H for converting the image of the imaging system BB ′ to the image of the imaging system AA ′ is expressed by Expression (1) (T represents transposition).

The planar projective transformation matrix H is a 3 × 3 matrix. The pixel coordinates of the images obtained by the imaging systems AA ′ and BB ′ are expressed as homogeneous coordinates such as p = (x, y, 1) ^T and p ′ = (x ′, y ′, 1) ^T. In other words, the conversion equation shown by the equation (2) is established.

  Note that α is a scale factor for each pixel obtained by solving the bottom row of Equation (2).

  With this conversion formula, the image of the imaging system BB ′ can be converted into an image as if it were captured by the imaging system A-A ′. However, as described above, the point on the reference plane can be converted to immovable, but the point that does not exist on the reference plane is not moved but is copied to the moved position.

  Note that the image conversion processing method performed by the two-dimensional geometric conversion processing unit 74 is not limited to the planar projective conversion, and may be another image conversion method. For example, affine transformation may be used. The position of the C arm 23 can be detected by a sensor (not shown).

  The two-dimensional geometric transformation processing unit 74 supplies the second perspective image data after the image transformation processing to the motion vector calculation unit 75 and the continuous perspective image data generation unit 80.

  In step S <b> 5, the motion vector calculation unit 75 acquires the first perspective image data supplied from the first perspective image data acquisition unit 78, and also performs the first after the image conversion process supplied from the two-dimensional geometric conversion processing unit 74. 2-perspective image data is acquired. The motion vector calculation unit 75 compares the image based on the first perspective image data constituting the continuous perspective image continuous in time series with the image based on the second perspective image data after the image conversion process. Then, the motion vector calculation unit 75 calculates difference information between the two images (difference information between frames), and calculates a motion vector for expressing a change in the image in a predetermined image region.

  In this case, as described with reference to FIGS. 6 and 7, the moving direction of the image or the point accompanying the plane projective transformation differs depending on whether the image or the point is above or below the reference plane. For example, as shown in FIG. 7, when the movement direction in the X-axis direction accompanying the arc motion of the X-ray tube 21 is the positive direction of the X-axis, images and points existing above the reference plane are subjected to plane projective transformation. Along with this, it moves in the negative direction of the X axis represented by the arrow K.

  On the other hand, an image or a point existing below the reference plane has an arrow with a plane projective transformation when the movement direction in the X-axis direction accompanying the arc movement of the X-ray tube 21 is the positive direction of the X-axis. Move in the positive direction of the X-axis represented by L.

  Then, the motion vector calculation unit 75 recognizes the first perspective image data photographed on the straight line AA ′ in order to recognize the direction of the image and the movement of the point accompanying the plane projective transformation by the two-dimensional geometric transformation processing unit 74. A motion vector between images between the image based on the image and the image based on the second perspective image data photographed on the straight line BB ′ is calculated.

  Specifically, the motion vector calculation unit 75 uses SAD (Sum of Absolute Difference) that uses the absolute value of the difference between the luminance values of the pixels at the same position, or SSD (Sum) that uses the square of the difference between the luminance values of the pixels at the same position. of Squared Difference), or block matching using similarity between image regions such as normalized correlation.

  Then, the motion vector calculation unit 75 is between the image based on the first perspective image data photographed on the straight line AA ′ and the image based on the second perspective image data photographed on the straight line BB ′. The motion vector between the images is calculated for each pixel or image region.

  FIG. 9 is an explanatory diagram for describing motion vector calculation by the motion vector calculation unit 75.

  FIG. 9 shows a fluoroscopic image immediately after the distal end portion of the wire passes through the blood vessel branch portion by an operation of the wire or the like by the operator. It is assumed that the blood vessel before branching is substantially included in the reference plane, the central blood vessel after branching is located above the reference plane, and the left and right blood vessels after branching are below the reference plane. Shall be on the side. In addition, it is assumed in advance that the blood vessel that the surgeon wants to pass the wire is a central branch blood vessel that exists above the reference plane.

  Here, it is assumed that the motion vector of the tip portion of the wire is obtained by using a fluoroscopic image obtained by moving (rotating) the C arm 23 from the position A to the position B in a circular arc (see FIG. 7).

  For example, as shown in FIG. 9, the image and the motion vector of the point associated with the planar projective transformation can be obtained by using the X axis if the tip of the wire advances through the central blood vessel after branching by an operation of the wire by the operator. The negative direction.

  On the other hand, if the distal end of the wire advances through the left or right blood vessel after branching by an operation of the wire or the like by the surgeon, the image or point motion vector associated with the planar projective transformation is Positive direction.

  When the X-ray diagnostic apparatus 1 can take an image of the patient (subject) P at a sufficiently short time interval compared to the wire movement or body movement, the optical flow obtained by the luminance gradient method or the like is used as the motion vector. It is possible to use it for calculation.

  In this case, since matching is not used, there is an advantage that there is no possibility of an error associated with matching by matching.

  Also, when explaining the concept of the three-dimensional position determination method, it is assumed that there is no movement of a medical device such as a wire or body movement of the patient P in order to simplify the explanation, but the motion vector is calculated more accurately. In order to do so, it is necessary to consider these.

  Here, when there is a body motion of the patient P, the body motion component is added to the motion vector calculated by the motion vector calculation unit 75, so that a large motion vector is also generated in the wire region substantially included in the reference plane. May come out.

  In this case, a motion vector is obtained for the wire region substantially included in the reference plane or the entire image, an arbitrary statistic such as a simple average or a robust statistic such as RANSAC is obtained, and the statistic is used as a body motion component. That is, the motion vector can be corrected by subtracting the statistic from the motion vector calculated by the motion vector calculation unit 75.

  Thereby, the X-ray diagnostic apparatus 1 of this embodiment can obtain | require correctly the motion vector used as the foundation for determining the three-dimensional position of a medical instrument, even if body movement etc. of the patient P etc. arise.

  Furthermore, when it is necessary to automatically detect in the image the medical instrument for which the motion vector is calculated or in the vicinity thereof, the material of the instrument is, for example, a material that hardly transmits X-rays, such as metal. In consideration of the above, in the X-ray diagnostic apparatus 1 of the present embodiment, only these regions may be detected by a combination of region determination such as roof type (valley type) image filter superposition and threshold processing.

  Further, in the X-ray diagnostic apparatus 1 of the present embodiment, a region where a medical instrument such as a catheter is present can be detected by tracing (following) from the root of the catheter.

  The motion vector calculation unit 75 supplies information regarding the calculated motion vector to the three-dimensional position determination unit 76. The motion vector calculation unit 75 also supplies information related to the calculated motion vector to the display control unit 81.

  The display control unit 81 can cause the display device 39 to display an image (an icon such as an arrow) indicating the direction and magnitude of the motion vector calculated by the motion vector calculation unit 75 during display of the continuous fluoroscopic image. .

  Here, the image indicating the direction and size of the motion vector is, for example, an icon such as an arrow shown in FIG. The arrow icon may be displayed in color. Thus, the operator can easily confirm and know the three-dimensional position of the medical instrument inserted into the blood vessel while viewing the continuous fluoroscopic image.

  In step S <b> 6, the three-dimensional position determination unit 76 performs the intravascular operation based on the information on the reference plane set by the reference plane setting unit 73 and the information on the motion vector calculated by the motion vector calculation unit 75. Determine a three-dimensional position for the medical device. That is, the three-dimensional position determination unit 76 determines whether the medical instrument during the intravascular operation is located in a region in the Y-axis positive direction or in the Y-axis negative direction with respect to the reference plane.

  Specifically, when the image or point motion vector accompanying the plane projective transformation by the two-dimensional geometric transformation processing unit 74 is in the negative direction of the X axis, the X axis direction accompanying the circular motion of the X-ray tube 21 This is the direction opposite to the forward direction of the X axis, which is the moving direction. In this case, the three-dimensional position determination unit 76 can determine based on the information on the motion vector that the blood vessel that the operator wants to pass through the wire has progressed to the central branch blood vessel that exists above the reference plane. it can.

  On the other hand, when the image or point motion vector accompanying the plane projective transformation by the two-dimensional geometric transformation processing unit 74 is in the positive direction of the X axis, the moving direction in the X axis direction accompanying the arc motion of the X-ray tube 21 It is the same direction as the positive direction of a certain X axis. In this case, based on the information about the motion vector, the three-dimensional position determination unit 76 determines that the blood vessel that the operator wants to pass through the wire has progressed to one of the left and right branch blood vessels that exist below the reference plane. Can be determined.

  The three-dimensional position determination unit 76 supplies the determination result to the three-dimensional position notification unit 77.

  In addition, when it is difficult to determine only the amount of displacement from the reference plane due to the influence of non-uniform body movement or disturbance, the three-dimensional posture can be estimated from the motion vector distribution of the medical device.

  FIG. 10 is a diagram in which the magnitude of the motion vector is plotted following (tracking) from the base position of the wire to the tip portion.

  As described so far, the motion vector indicates a state in which a pixel or a region existing at a position away from the reference plane moves by the image conversion process. For this reason, it is considered that the magnitude of the motion vector basically increases linearly as the position of the distal end portion of the medical instrument moves away from the reference plane.

  Here, when a medical instrument is inserted into a blood vessel that is not desired by the surgeon, it is conceivable that the magnitude of the motion vector locally increases and the inclination increases.

  Therefore, in consideration of the distribution of motion vectors of medical devices that have progressed in blood vessels, the three-dimensional position of the medical device in the currently progressing blood vessels is estimated based on the distribution trend. It may be. That is, you may make it estimate the three-dimensional position with respect to the advancing direction from the advancing direction of the medical instrument until now. Alternatively, a vector difference value may be used.

  In this case, instead of the reference plane determined only by the distance from the X-ray tube 21, a plane including a blood vessel may be provided as the reference plane. For example, by resetting the reference plane from the initially set reference plane state to the plane including the blood vessel, and linearly approximating the vector in which the medical instrument such as a wire is inserted into the blood vessel of the subject P, Based on the magnitude of the motion vector of the medical instrument, the vertical position of the medical instrument in the body of the subject can be estimated and determined.

  The motion vector distribution can be approximated by arbitrary statistical estimation such as linear approximation (linear approximation) or Kalman filter. In this case, with respect to the approximation and the motion vector, preset tolerance values (numerical values relating to average, variance, angle, pixel value, etc. (including absolute values)) or tolerance values estimated from anatomical structures By comparing the motion vectors, the tip of the wire should originally face upward (front side), but in fact it points downward and the direction of bending of the wire is wrong. Can be determined.

  As a result, it is possible to determine the three-dimensional position of the medical instrument for only a motion vector with a value exceeding the preset allowable value (outlier) and notify the fact.

  In step S <b> 7, the three-dimensional position notification unit 77 notifies the operator of the three-dimensional position of the medical instrument inserted in the blood vessel based on the determination result supplied from the three-dimensional position determination unit 76.

  Specifically, the three-dimensional position notification unit 77 supplies information related to the three-dimensional position of the medical device based on the determination result to the display control unit 81, and receives information related to the three-dimensional position of the medical device via the display control unit 81. It is displayed on the display device 39. At this time, the information regarding the three-dimensional position of the medical instrument is simultaneously displayed during the display of the continuous fluoroscopic image.

  For example, “The 3D position of the medical device is above the reference plane. The direction of travel of the medical device is correct.” “The 3D position of the medical device is below the reference plane. A message such as “The direction is wrong” is displayed on the display device 39 as information on the three-dimensional position of the medical instrument.

  As a result, the operator can easily confirm the three-dimensional position of the medical instrument inserted in the blood vessel while viewing the continuous fluoroscopic image, and the three-dimensional position inserted in the blood vessel is scheduled. Even if they are different from each other, it can be corrected immediately so that the direction of travel of the medical device is correct.

  In addition, the operation can be determined on the upper side or the lower side of the reference plane simply by the direction of the motion vector (the reverse may be possible by setting in advance), and the operator can be notified of this. In addition, the X-ray diagnostic apparatus 1 according to the present embodiment provides two-dimensional information (for example, FIG. 9) called a continuous fluoroscopic image, and simultaneously provides three-dimensional position information (for example, FIG. 10) of a medical instrument. it can.

  In the notification process of step S7, the three-dimensional position information related to the medical instrument is notified to the operator by a message using the display device 39, but is not limited to such a case. For example, notification by voice or signal sound using the speaker 42 may be used, and notification by image display other than characters (display of an icon such as an arrow, color display of a corresponding portion of a medical device, color display, contrast enhancement display, etc.) However, it may be notified by vibration of a vibrator or the like, and various other notification methods are conceivable.

  In addition, when determining using an allowable value, the operator may be notified of not only the determination result of whether it is an allowable range, but also the posture direction and numerical information of the difference from the allowable range, Any information regarding the required three-dimensional posture may be notified.

  Further, in the present embodiment, an image (in which the direction and the size of the motion vector calculated by the motion vector calculation unit 75 are displayed during the continuous perspective image display without performing the determination process by the three-dimensional position determination unit 76 ( Only icons (such as arrows) may be displayed on the display device 39.

  In step S <b> 8, the input receiving unit 71 receives an input as to whether or not to end the X-ray imaging process for acquiring the three-dimensional position information (three-dimensional posture information) controlled by the X-ray imaging execution control unit 72. Accept. And the input reception part 71 determines whether the input about whether to complete | finish the X-ray imaging process for acquisition of three-dimensional position information was received.

  In step S8, when it is determined that the input for ending the X-ray imaging process for acquiring the three-dimensional position information is not accepted, the process returns to step S2, and the processes after step S2 are performed for a predetermined time. It is repeatedly executed every time (for example, for 1 second).

  As a result, the X-ray diagnostic apparatus 1 according to the present embodiment has a predetermined time (for example, 1 second) until it is determined that an input for ending the X-ray imaging process for acquiring the three-dimensional position information is accepted. Every time, it is possible to acquire the three-dimensional position information regarding the medical instrument during the intravascular operation and notify the operator.

  On the other hand, when it is determined in step S8 that an input to end the X-ray imaging process for obtaining the three-dimensional position information has been accepted, the three-dimensional position notification process ends.

  When the operator inputs again that the X-ray imaging process for acquiring the three-dimensional position information regarding the medical instrument undergoing the endovascular operation is started, the processes from step S2 to S7 are executed. .

  In addition, the X-ray diagnostic apparatus 1 according to the present embodiment obtains a transformation basic matrix from the corresponding feature points when a plurality of (8 or more) corresponding feature points are obtained between two or more fluoroscopic images, It is also possible to obtain a deviation amount, perform a three-dimensional reconstruction of feature points, so-called multiview stereo, and estimate the three-dimensional posture of the operating tool.

  Furthermore, the X-ray diagnostic apparatus 1 according to the present embodiment, when executing the three-dimensional position notification process described with reference to FIG. (Subject) Stereo observation for photographing P from two viewpoints may be used in combination.

  Further, in the case of imaging using a contrast agent, the X-ray diagnostic apparatus 1 of the present embodiment may acquire information regarding the three-dimensional position of the blood vessel itself and notify the operator of the information.

  As described above, in the X-ray diagnostic apparatus 1 according to the present embodiment, when a fluoroscopic image is captured from a plurality of viewpoints and a continuous fluoroscopic image is displayed, it is as if the second fluoroscopic image captured from the second viewpoint is the first. It is possible to perform image conversion processing so as to obtain a perspective image captured from one viewpoint, and to display on the display device 39 the motion of the image or region, or the motion vector that is generated by this image conversion processing.

  Thereby, the surgeon can easily recognize what three-dimensional posture (three-dimensional position) the medical instrument is in the body of the subject only by the display itself of the display device 39. The X-ray diagnostic apparatus 1 then takes any three-dimensional posture (three-dimensional position) of the medical instrument in the body of the subject based on the motion of the image or area, or the motion vector, which is generated along with the image conversion process. Since the determination can be made, the operator can be notified of information regarding the three-dimensional position regarding the medical instrument.

  This notification process can be performed if the motion of the image or area or the motion vector that accompanies this image conversion process is known, even if it does not have an X-ray diagnostic apparatus 1 having a single plane or a stereo tube. The present invention can be applied even to the X-ray diagnostic apparatus 1.

  Therefore, the X-ray diagnostic apparatus 1 of the present embodiment allows the medical device to be in any three-dimensional posture (three-dimensional position) in the body of the subject during the intravascular operation easily and inexpensively while suppressing the exposure dose. Can be notified to the surgeon or the outside.

  In this way, the surgeon can reliably know the three-dimensional position of the medical instrument without depending on the experience of operating the medical instrument. It is possible to prevent mistakes caused by erroneous operations such as a wrong placement posture of a large-vessel perforated stent or the like.

  Further, according to the X-ray diagnostic apparatus 1 of the present embodiment, there is no need for three-dimensional reconstruction such as scanning with an X-ray CT apparatus or XR-3D roadmap, and the rotational speed and operating angle of the C arm 23 are reduced. (5 degrees / second, 5 degree range, etc.).

  As a result, the danger to the surgeon associated with X-ray imaging can be eliminated as much as possible, and the imaging / processing time required for one-time estimation of the three-dimensional posture can be shortened, which can be used frequently during the operation.

  Furthermore, since the relative amount of the motion vector is used, it is possible to estimate the three-dimensional posture (three-dimensional position) even in a part with body movement such as the chest and abdomen. By reducing the time required for checking and adjusting the three-dimensional posture, the burden on the patient and the operator can be greatly reduced.

  Further, in step S2 shown in FIG. 8, the reference plane setting unit 73 appropriately determines a desired reference after the X-ray imaging process for acquiring the three-dimensional position information regarding the medical instrument during the intravascular operation is started. You can reset the face.

  That is, the reference plane setting process in step S2 can be executed after the determination process in step S8 to set the reference plane again, or the already set reference plane may be used as it is. Further, the reference plane setting unit 73 may set a reference plane that includes the blood vessel to be observed as described above based on the input of the input device 38 operated by the operator.

  Thereby, it is possible to suitably determine what three-dimensional position the medical instrument in the blood vessel has with respect to an arbitrary reference plane during the intravascular operation.

  Note that the reference plane setting unit 73 supplies information on the set reference plane to the two-dimensional geometric transformation processing unit 74 and the three-dimensional position determination unit 76 each time.

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

  Further, in the embodiment of the present invention, each step of the flowchart shows an example of processing that is performed in time series in the order described. The process to be executed is also included.

1 X-ray diagnostic apparatus 21 X-ray tube 22 X-ray detection apparatus 22a I.
22b TV camera 23 C arm 24 Top plate 25 High voltage supply device 26 Drive mechanism 31 A / D conversion circuit 32 Image generation / processing circuit 33 Image memory 34 CPU
35 HDD
36 Memory 37 System control unit 38 Input device 39 Display device 40 Storage medium drive 41 Communication control device 42 Speaker 43 Bus 51 Flat detector 52 DAS
60, 61 Image processing unit 71 Input reception unit 72 X-ray imaging execution control unit 73 Reference plane setting unit 74 Two-dimensional geometric transformation processing unit 75 Motion vector calculation unit 76 Three-dimensional position determination unit 77 Three-dimensional position notification unit 78 First perspective Image data acquisition unit 79 Second perspective image data acquisition unit 80 Continuous perspective image data generation unit 81 Display control unit

Claims (14)

C-arm,
An X-ray tube provided at one end of the C-arm for exposing the subject to X-rays;
An X-ray detector which is provided at the other end of the C-arm while facing the X-ray tube and detects X-rays;
When a medical instrument is inserted into the subject, the C-arm is rotated to perform X-ray imaging at each of a plurality of viewpoints including at least a first viewpoint and a second viewpoint. Acquisition means for acquiring first fluoroscopic image data to be radiographed and second fluoroscopic image data to be X-ray radiographed from the second viewpoint in time series continuously with the first fluoroscopic image data;
Image conversion means for performing image conversion processing on the second fluoroscopic image data acquired by the acquisition means;
Difference information between the image based on the first perspective image data and the image based on the second perspective image data after the image conversion processing by the image conversion unit is calculated for each pixel or image region, and a motion vector is calculated. Motion vector calculating means for
An image based on the first fluoroscopic image data and an image based on the second fluoroscopic image data after the image conversion processing by the image converting means are displayed as a continuous fluoroscopic image continuous in time series, and the continuous fluoroscopy Display means for displaying an image according to the motion vector calculated by the motion vector calculation means during display of the image;
X-ray diagnostic apparatus. Determination means for determining a three-dimensional position of the medical instrument inserted into the subject with respect to the reference plane based on information on the motion vector calculated by the motion vector calculation means and information on the reference plane;
Based on a determination result by the determination unit, a notification unit that notifies information about a three-dimensional position of the medical instrument with respect to the reference plane;
The X-ray diagnostic apparatus according to claim 1, further comprising: The notification means includes
The information on the three-dimensional position of the medical instrument with respect to the reference plane is notified by displaying the information on the three-dimensional position of the medical instrument with respect to the reference plane on the display unit by displaying characters or images. Line diagnostic equipment. The character display or image display is
The X-ray diagnostic apparatus according to claim 3, wherein color display or contrast enhancement is further performed by the display unit. The notification means includes
The X-ray diagnostic apparatus according to claim 2, wherein information related to a three-dimensional position of the medical instrument relative to the reference plane is notified by outputting information relating to the three-dimensional position of the medical instrument relative to the reference plane as sound or signal sound. . The X-ray diagnostic apparatus according to any one of claims 2 to 5, further comprising setting means for setting a horizontal plane passing through a center of the subject or an arbitrary plane related to the subject as the reference plane. The determination means includes
The three-dimensional position of the medical instrument inserted into the subject with respect to the reference plane is determined based on the direction and magnitude of the motion vector calculated by the motion vector calculating means. The X-ray diagnostic apparatus according to Item 1. The determination means includes
Based on the motion vector distribution calculated by the motion vector calculation means and a preset allowable value, the medical instrument inserted into the subject has a three-dimensional position with respect to the reference plane or the medical instrument thus far The X-ray diagnostic apparatus according to any one of claims 2 to 7, wherein a three-dimensional position with respect to the traveling direction is determined. The display means includes
The X-ray diagnostic apparatus according to any one of claims 1 to 8, wherein an image indicating a direction and a magnitude of a motion vector calculated by the motion vector calculation unit is displayed during display of the continuous fluoroscopic image. The image conversion means includes
The image conversion process is performed on the image based on the second fluoroscopic image data so as to become an image based on the first fluoroscopic image data which is X-rayed from the first viewpoint. The X-ray diagnostic apparatus according to Item. The X-ray diagnosis apparatus according to claim 1, wherein the image conversion process performed by the image conversion unit is a two-dimensional geometric conversion process. The two-dimensional geometric transformation process includes:
The X-ray diagnostic apparatus according to claim 11, wherein the X-ray diagnostic apparatus is a planar projective transformation process or an affine transformation process. An input accepting means for accepting an input to start X-ray imaging at each of a plurality of viewpoints including at least the first viewpoint and the second viewpoint by rotating the C-arm;
Execution control for controlling to execute X-ray imaging at each of a plurality of viewpoints including at least the first viewpoint and the second viewpoint by rotating the C-arm when the input is received by the input receiving means. Means,
The X-ray diagnostic apparatus according to any one of claims 1 to 12, further comprising: The execution control means includes
X-ray imaging is repeated every predetermined time until an input indicating completion is received by the input receiving means, and the C-arm is rotated to rotate a plurality of viewpoints including at least the first viewpoint and the second viewpoint. The X-ray diagnostic apparatus according to claim 13, wherein the X-ray diagnostic apparatus is controlled to execute X-ray imaging.

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