JP2015139624A - ultrasonic diagnostic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately display a state of a biological tissue caused by paracentesis.SOLUTION: An ultrasonic diagnostic apparatus includes: a tomographic image generation unit 20 that generates a tomographic image frame data on the basis of ultrasonic waves reflected at a subject 16 to be punctured; displacement data generation unit 28 that generates displacement image data representing displacement of the biological tissue of the subject 16 on the basis of a plurality of frames of tomographic image frame data; and an image synthesis unit 22 that displays, on a monitor 30, the displacement image representing displacement state of the biological tissue, superimposed on the tomographic image, on the basis of the tomographic frame data and the displacement image data. This configuration can represent displacement state such as deformation of the biological tissue caused by the paracentesis.

Description

  The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to an apparatus for measuring a displacement of a living tissue.

  A technique called puncture for performing drug injection, cell extraction, cell ablation, etc. by inserting a needle into a living tissue is widely performed. As the puncture needle, a puncture needle having a structure corresponding to the purpose of the treatment is used. For example, a hollow puncture needle having an opening at the tip is used for drug injection, cell extraction, and the like. Further, when ablating a tumor, a puncture needle having an electrode that radiates electromagnetic waves provided at the tip is used.

  When puncturing, a puncture adapter is often used to puncture a puncture needle at an appropriate angle at an appropriate position on a living body. The puncture adapter is an instrument attached to the ultrasonic probe and guides the puncture needle to an appropriate position and direction. The puncture is performed while displaying the puncture target site on the monitor of the ultrasonic diagnostic apparatus. The practitioner touches the living body with the ultrasonic probe, and punctures the puncture needle toward the puncture target site in a state where the puncture target site is displayed on the monitor. Then, referring to the puncture needle and puncture target site displayed on the monitor, puncture is performed while confirming the position and posture of the puncture needle, the position of the puncture target site, and the like.

  Patent Document 1 below describes a puncture adapter that can be attached to and detached from an ultrasonic probe. By attaching the puncture adapter to the ultrasonic probe, a guide path for the puncture needle is formed beside the ultrasonic probe. When puncturing, a puncture needle is passed through the guide path. The puncture needle is inserted into the living body while maintaining a predetermined posture along the guide route. Patent Document 2 describes an ultrasonic diagnostic apparatus that displays a straight line indicating an approximate path of entry of a puncture needle on an ultrasonic image.

JP 2010-172565 A JP-A-6-183 JP 2012-143389 A

  At the time of puncture, the practitioner determines each posture of the ultrasonic probe and the puncture needle using a puncture adapter or the like so that the puncture target site and the puncture needle are displayed on the monitor and the puncture needle reaches the puncture target site. However, depending on the positional relationship between the ultrasonic probe and the puncture needle, the visibility of the puncture needle on the monitor may be reduced, making it difficult to perform puncture.

  Therefore, as described in Patent Document 3, an ultrasonic diagnostic apparatus that calculates strain of a living tissue using the Doppler method, and identifies and displays the position of the puncture needle based on the calculated strain is considered. Yes. However, since the Doppler method has a large amount of calculation, it may be difficult to display quickly responding to the displacement of the puncture needle and the living tissue.

  An object of this invention is to display appropriately the state of the biological tissue accompanying puncture.

The present invention provides a tomographic image generation unit that generates tomographic image frame data based on ultrasonic waves reflected by a punctured biological tissue, and a displacement state of the biological tissue based on a plurality of frames of the tomographic image frame data. A displacement data generator for generating displacement data to be shown;
An image composition unit that displays a displacement state of the living tissue on a display unit together with a tomographic image based on the tomographic image frame data and the displacement data.

  According to the present invention, the displacement state of the living tissue is displayed on the display unit together with the tomographic image. As a result, the displacement state such as distortion of the living tissue accompanying puncture is easily shown to the user. Generally, when puncture is performed on a living tissue, the displacement state of the living tissue around the puncture needle changes according to the path of the puncture needle. Therefore, according to the present invention, it becomes easy for the user to grasp the course of the puncture needle. The displacement data in the present invention may be image data or data that gives additional information to the tomographic image frame data.

  Preferably, the displacement data generation unit generates image data indicating the direction of displacement of the living tissue by a drawing element as the displacement data, and the image composition unit superimposes an image based on the displacement data on the tomographic image. Displayed on the display unit.

  The drawing element in the present invention is, for example, a figure such as an arrow, a color, or a combination thereof. According to the present invention, the direction of displacement of the living tissue is indicated by the drawing element. Thereby, the user can easily grasp the displacement state of the living tissue through vision.

  Preferably, the displacement data generation unit generates image data indicating a specific direction component of the displacement of the living tissue as the displacement data.

  According to the present invention, a specific directional component of biological tissue displacement is indicated. Thereby, an image suitable for facilitating puncturing can be displayed.

  The present invention provides a tomographic image generation unit that generates tomographic image frame data based on ultrasonic waves reflected by a punctured biological tissue, and a displacement state of the biological tissue based on a plurality of frames of the tomographic image frame data. A displacement data generation unit that generates displacement data to be shown; a rotation characteristic data generation unit that generates rotation characteristic data indicating rotation characteristics of the living tissue based on the displacement data; the tomographic image frame data and the rotation characteristic data; And an image synthesizing unit that displays a rotational characteristic of the living tissue together with a tomographic image on a display unit.

  According to the present invention, the rotational characteristics of the biological tissue are displayed on the display unit together with the tomographic image. As a result, the rotational characteristics such as rotational distortion of the living tissue accompanying puncture are shown to the user in an easily understandable manner. Generally, when puncture is performed on a living tissue, the rotational characteristics of the living tissue around the puncture needle change according to the path of the puncture needle. Therefore, according to the present invention, it becomes easy for the user to grasp the course of the puncture needle. The displacement data and the rotation characteristic data in the present invention may be image data or data that gives additional information to the tomographic image frame data.

  Preferably, the displacement data generation unit generates data indicating the displacement of the living tissue as the displacement data, the rotation characteristic data generation unit performs a rotation operation on the displacement of the living tissue, and the living tissue The rotational component of the displacement is determined as the rotational characteristic of the living tissue.

  In the present invention, rotation characteristics are obtained by rotation calculation as vector calculation. As a result, rotational characteristics are easily obtained.

  Preferably, the rotation characteristic data generation unit generates image data indicating a rotation direction indicated by the rotation component by a drawing element as the rotation characteristic data, and the image synthesis unit generates an image based on the rotation characteristic data. The image is displayed on the display unit so as to overlap the image.

  The drawing element in the present invention is, for example, a figure such as an arrow, a color, or a combination thereof. According to the present invention, the rotational characteristic of the living tissue is indicated by the drawing element. Accordingly, the user can easily grasp the rotation characteristics of the living tissue through vision.

  Preferably, the image composition unit displays the rotational characteristics and displacement state of the living tissue together with the tomographic image on the display unit.

  According to the present invention, the rotational characteristics and displacement state of the living tissue are displayed together with the tomographic image. Thereby, the rotation characteristics such as the rotational distortion of the living tissue accompanying puncture and the displacement state such as the distortion of the living tissue accompanying puncturing are easily shown to the user. Generally, when a puncture is performed on a living tissue, the rotational characteristics and displacement state around the puncture needle change according to the path of the puncture needle. Therefore, according to the present invention, it becomes easy for the user to grasp the course of the puncture needle.

  ADVANTAGE OF THE INVENTION According to this invention, the state of the biological tissue accompanying puncture can be displayed appropriately.

1 is a diagram showing an ultrasonic diagnostic apparatus according to a first embodiment of the present invention. It is a figure which shows notionally the definition of the displacement of a biological tissue. It is a figure which shows the example of the image shown on a monitor. It is a figure which shows the example of the image by which the direction of the displacement of the biological tissue was shown with the arrow with the color. It is a figure which shows the image showing only the specific direction component of the displacement of a biological tissue. It is a figure which shows the image in which only the specific direction component of the displacement of a biological tissue was shown with the color and the arrow. It is a figure which shows the image from which the correspondence of the displacement direction of a biological tissue and a color was determined according to the puncture needle penetration direction. It is a figure which shows the ultrasonic diagnosing device which concerns on 2nd Embodiment of this invention. It is a figure explaining the process which calculates | requires rotation amount. It is a figure which shows the image on which the rotation characteristic image was superimposed on the tomographic image. It is a figure which shows the image by which the rotation direction of the biological tissue was shown with the arrow which shows a rotation direction with a color.

  FIG. 1 shows the configuration of an ultrasonic diagnostic apparatus according to the first embodiment of the present invention. The ultrasonic diagnostic apparatus scans an ultrasonic beam transmitted / received to / from the subject 16, displays a tomographic image based on the received ultrasonic wave, and displaces a tissue (biological tissue) of the subject 16. Is measured and displayed. The displacement of the living tissue represents the distance that the living tissue moves per predetermined time. The displacement is a vector quantity having a direction and a magnitude, and can be displayed by a combination of color and brightness, a figure such as an arrow, a pair of two component values, or the like.

  Of the components shown in FIG. 1, a portion surrounded by a one-dot chain line constitutes a main unit 32 as hardware. The main unit 32 includes a processor, and the processor configures a circuit included in the main unit 32 according to a predetermined program. The operation unit 34 includes a user interface such as a trackball and a mouse. The control unit 36 controls the main unit 32 in accordance with an operation on the operation unit 34. For example, the control unit 36 performs control such as start or stop of processing of the main unit 32, switching of a measurement state, switching of image data output from the main unit 32 to the monitor 30, and the like.

  At the time of measurement, the probe 14 is brought into contact with the surface of the subject 16. A puncture adapter 15 is attached to the probe 14, and the puncture adapter 15 guides the puncture needle 17 to an appropriate position and direction. The probe 14 includes a plurality of ultrasonic transducers. The transmission unit 12 outputs a transmission signal to each ultrasonic transducer of the probe 14 based on control by the beam control unit 10. As a result, ultrasonic waves are transmitted from the probe 14. The transmission unit 12 adjusts the delay time of each transmission signal according to the control of the beam control unit 10, forms a transmission ultrasonic beam at the probe 14, and further scans the subject 16 with the transmission ultrasonic beam. When the ultrasound reflected in the subject 16 is received by each ultrasound transducer of the probe 14, each ultrasound transducer outputs an electrical signal corresponding to the received ultrasound to the receiving unit 18. Under the control of the beam control unit 10, the reception unit 18 generates a reception signal by phasing and adding the electrical signals output from the ultrasonic transducers of the probe 14, and outputs the reception signal to the tomographic image generation unit 20. Accordingly, a reception ultrasonic beam is formed in the probe 14, and a reception signal corresponding to the reception ultrasonic beam is output from the reception unit 18 to the tomographic image generation unit 20.

  In the above description, the process of adopting a probe including a plurality of ultrasonic transducers and electrically scanning an ultrasonic beam has been described. Mechanical scanning may be performed instead of such electrical scanning. In this case, the probe 14 includes a mechanism that mechanically changes the position or orientation of the ultrasonic transducer. The scanning of the ultrasonic beam is performed by mechanically changing the position or orientation of the ultrasonic transducer while causing the ultrasonic transducer to transmit and receive ultrasonic waves.

  The tomographic image generation unit 20 generates tomographic image frame data based on the received signal obtained for each ultrasonic beam direction, and outputs it to the image synthesis unit 22. One tomographic image frame data corresponds to one tomographic image. The beam control unit 10, the transmission unit 12, the probe 14, the reception unit 18, and the tomographic image generation unit 20 generate tomographic image frame data one after another as time elapses, and output them to the image synthesis unit 22. The tomographic image generation unit 20 stores tomographic image frame data for a plurality of frames (N frames) retroactively from the present time. Further, the tomographic image generation unit 20 may store all the tomographic image frame data from the start of scanning of the ultrasonic beam to the present time.

  As will be described later, displacement image data indicating the displacement state of the living tissue is successively output from the displacement data generation unit 28 over time. Based on the tomographic image frame data and the displacement image data temporally corresponding to the tomographic image frame data, the image composition unit 22 converts the tomographic image data indicating the tomographic / displacement image obtained by superimposing the displacement image on the tomographic image. It produces | generates as displacement image data, and outputs it to the monitor 30 as a display part. The monitor 30 displays a tomographic / displacement image.

  A configuration and processing for generating displacement image data will be described. The displacement image data is generated by the frame data acquisition unit 24, the displacement measurement unit 26, and the displacement data generation unit 28. As described above, the tomographic image generation unit 20 stores tomographic image frame data for a plurality of frames retroactively from the present time. The frame data acquisition unit 24 acquires tomographic image frame data for a plurality of frames going back to the past from the present time from the tomographic image generation unit 20 and outputs the acquired data to the displacement measurement unit 26. The displacement measuring unit 26 obtains the displacement of the living tissue for each position on the latest tomographic image based on the tomographic image frame data for a plurality of frames.

  For example, the frame data acquisition unit 24 acquires the latest tomographic image frame data and the previous tomographic image frame data from the tomographic image generation unit 20 and outputs them to the displacement measurement unit 26. The displacement measuring unit 26 obtains the displacement of the living tissue at each position on the latest tomographic image based on the latest tomographic image frame data and the tomographic image frame data one frame before.

  As a method for obtaining the displacement of the living tissue, based on the comparison between the tomographic image one frame before and the latest tomographic image, each position on the tomographic image one frame before is moved to the corresponding position on the latest tomographic image. There is a method for obtaining a movement vector. In this case, the movement vector to each corresponding position on the latest tomographic image is obtained as the displacement of the living tissue at each corresponding position on the latest tomographic image. The displacement of the living tissue thus obtained represents the distance that the living tissue has moved per frame time. The moving speed of the living tissue can be obtained by multiplying the displacement of the living tissue by the frame rate.

  FIG. 2 conceptually shows the definition of the displacement of the living tissue. FIG. 2A shows a tomographic image one frame before, and FIG. 2B shows the latest tomographic image. The images represented by the pixel 38-1 and the pixel 38-2 in the tomographic image one frame before have moved to the positions of the pixel 40-1 and the pixel 40-2 in the latest tomographic image, respectively. Since each movement vector is (ΔX1, ΔY2) and (ΔX2, ΔY2), the displacement of the living tissue at the position of the pixel 40-1 and the pixel 40-2 of the latest tomographic image is (ΔX1, ΔY2), respectively. And (ΔX2, ΔY2).

  Examples of processing for obtaining the displacement of the living tissue at each position include the following. The displacement measuring unit 26 obtains a correlation value between the trial strain image obtained by trial movement of each pixel on the tomographic image one frame before and the latest tomographic image. Here, the correlation value is a value indicating the degree of approximation between the two images. Various methods for obtaining the correlation value are considered among those skilled in the art. When the correlation value between the trial strain image and the latest tomographic image exceeds a predetermined size, the displacement measuring unit 26 performs the process for each pixel of the tomographic image one frame before that is the basis of the trial strain image. The movement vector is obtained as the displacement of the biological tissue for each pixel of the latest tomographic image corresponding to each pixel. When the correlation value between the trial strain image and the latest tomographic image is equal to or smaller than a predetermined magnitude, the displacement measuring unit 26 changes the movement vector and the correlation value with the latest tomographic image has a predetermined magnitude. Search for more than a trial distortion image.

  Returning to FIG. 1, the displacement measuring unit 26 outputs the displacement of the living tissue at each position on the latest tomographic image to the displacement data generating unit 28. The displacement data generation unit 28 generates displacement image data indicating the displacement state of the biological tissue by color based on the displacement of the biological tissue at each position. That is, a process for obtaining a color corresponding to the displacement direction of the biological tissue for each pixel and associating it with each pixel, and a process for obtaining the luminance corresponding to the magnitude of the displacement of the biological tissue for each pixel and associating it with each pixel Execute.

  The displacement data generation unit 28 may store a direction versus color table in which colors are associated with the direction of displacement of the living tissue. In the direction-to-color table, for example, the right direction of the image is 0 °, the left rotation direction is the positive direction, the first color is associated with the direction of 0 ° to less than 90 °, and the direction is 90 ° to less than 180 °. The second color is associated with the second color, the third color is associated with the direction of 180 ° or more and less than 270 °, and the fourth color is associated with the direction of 270 ° or more and less than 360 ° (0 °). Each color may be determined by a mixing ratio of red, green, and blue. Furthermore, the displacement data generation unit 28 may store a direction vs. luminance table in which luminance is associated with the magnitude of displacement of the living tissue.

  Based on such association, the displacement data generation unit 28 obtains a displacement image in which the color and brightness corresponding to the displacement of the living tissue are mapped to each pixel of the tomographic image, and generates displacement image data indicating the displacement image. .

  As the tomographic image frame data is generated one after another in the tomographic image generating unit 20, the displacement data generating unit 28 generates displacement image data corresponding to each tomographic image frame data in time. The displacement data generation unit 28 sequentially outputs the displacement image data generated over time to the image composition unit 22. The obtained displacement image data may be data for one image with respect to the tomographic image frame data for a plurality of frames. In this case, the same displacement image data is temporally associated with the tomographic image frame data for a plurality of frames.

  Based on the tomographic image frame data and the displacement image data temporally corresponding to the tomographic image frame data, the image composition unit 22 converts the tomographic image data indicating the tomographic / displacement image obtained by superimposing the displacement image on the tomographic image. It generates as displacement image data and outputs it to the monitor 30. The monitor 30 displays a tomographic / displacement image.

  As a result, an image in which the displacement image is superimposed on the tomographic image is displayed on the monitor 30, and the change in the displacement state of the living tissue is displayed on the monitor 30 together with the moving image of the tomographic image. That is, along with the movement of the living tissue, the direction of displacement of the living tissue is indicated on the monitor 30 by color.

  The image composition unit 22 synthesizes these two image data so that an image based on one of the two image data can be seen through the image based on the other image data. That is, when combining the tomographic image frame data and the displacement image data, the tomographic image frame data and the displacement image data are combined so that the tomographic image can be seen through the displacement image. In such image composition processing, there is a method in which the pixels of one image are thinned out and the pixels of the other image are supplemented at the positions of the thinned pixels. Also, there is a technique that adds a pixel value of one image and a pixel value of the other image with a predetermined weight. For example, the pixel value of one image multiplied by α and the pixel value of the other image multiplied by (1−α) are added together. Here, α is the mixing ratio of the images, and is a positive number greater than 0 and less than 1.

  FIG. 3 shows an example of an image displayed on the monitor 30. On the tomographic image 44, the direction of displacement of the living tissue is shown by color together with the puncture needle image 46. On the upper left of the monitor 30, a color map 42 showing the correspondence between the direction of displacement of the living tissue and the color is shown. In the color map 42, the first color is associated with the direction from 0 ° to less than 90 °, with the x-axis positive direction being 0 ° and the left rotation direction being the positive direction, and the first color is in the direction from 90 ° to less than 180 °. 2 colors are associated with each other, the third color is associated with a direction between 180 ° and less than 270 °, and the fourth color is associated with a direction between 270 ° and less than 360 ° (0 °). Is shown. For example, the first color and the third color may be blue and red, respectively, and the second color and the fourth color may be intermediate colors such as purple, light blue, yellow-green, yellow, and orange.

  In the image of FIG. 3, it is shown that the direction of displacement of the biological tissue is a direction of 180 ° or more and less than 270 ° around the puncture needle image 46. That is, it is shown that the puncture needle advances in the lower left direction, and the living tissue is displaced in the lower left direction due to friction with the puncture needle. Further, it is shown that the direction of displacement of the living tissue is a direction of 270 ° or more and less than 360 ° in the upper left from the vicinity of the tip of the puncture needle. That is, it is shown that the living tissue is displaced in the lower right direction due to friction with the puncture needle. Further, it is shown that the direction of displacement of the living tissue is 90 ° or more and less than 180 ° in the lower right from the vicinity of the tip of the puncture needle. That is, it is shown that the living tissue is displaced in the upper left direction due to friction with the puncture needle.

  In the tomographic image of the ultrasonic diagnostic apparatus, depending on the positional relationship between the probe and the puncture needle, the image of the puncture needle may become unclear and visibility may be lowered, making it difficult to perform puncture. According to the ultrasonic diagnostic apparatus of the present invention, the direction of displacement of the living tissue is shown to the user as the practitioner along with the tomographic image. Thereby, the user can grasp the path of the puncture needle from the direction of displacement of the living tissue, and can easily perform puncture.

  The direction of displacement of the living tissue may be indicated by an arrow together with the color. In this case, based on the displacement of the living tissue at the position where the arrow is displayed, the displacement data generation unit 28 generates image data indicating the color and the arrow superimposed on the corresponding position on the tomographic image as the displacement image data. The direction and length indicated by the arrows correspond to the direction and length of displacement of the living tissue. FIG. 4 shows an example of an image in which the direction of displacement of the living tissue is indicated by an arrow together with the color.

  The direction of the displacement of the living tissue may be indicated by other figures such as a triangle in addition to the arrows. Further, the direction of displacement of the living tissue may be indicated by only a figure such as an arrow regardless of the color. In this case, the displacement data generation unit 28 generates, as displacement image data, image data that shows the figure superimposed on the corresponding position on the tomographic image based on the displacement of the living tissue at the position where the figure is displayed.

  Furthermore, the displacement data generation unit 28 may generate displacement image data that expresses only a specific direction component of the displacement of the living tissue by color. FIG. 5 shows an example in which a displacement image showing only a directional component of 180 ° or more and less than 270 ° with respect to the displacement of the living tissue is superimposed on the tomographic image 44. According to this image, the region in which the displacement of the living tissue includes a direction component of 180 ° or more and less than 270 ° is indicated by color. When the puncture needle advances from the upper right to the lower left, the living tissue is displaced to the lower left due to friction with the puncture needle. Therefore, the displacement of the living tissue around the puncture needle has a component in the lower left direction, and as shown in FIG. 5, the region including the directional component where the displacement of the living tissue is 180 ° or more and less than 270 ° A needle image 46 is shown around. FIG. 6 shows, as an application example, an image in which only a specific direction component of the displacement of the living tissue is represented by a color and an arrow.

  According to such a display, the component caught in the direction of the puncture needle is not displayed. Thereby, the user can grasp the path of the puncture needle from the specific direction component of the displacement of the living tissue, and can easily perform the puncture.

  When the direction of displacement of the living tissue is indicated by color, the correspondence between the direction of displacement of the living tissue and the color may be determined adaptively according to the direction in which the puncture needle is inserted. In the color map 43 of FIG. 7, the direction in which the puncture needle advances is 0 °, the left rotation direction is the positive direction, and the first color is associated with the direction of −45 ° or more and less than 45 °. The second color is associated with the direction less than, the third color is associated with the direction between 135 ° and less than 180 °, and the direction between −180 ° and less than −135 °, and between −135 ° and −45 °. It shows that the fourth color is associated with the direction of less than °. The color map 43 displayed on the display unit 30 may be rotated according to the angle of the puncture needle image 46.

  In order to generate such image data according to the color map 43, the displacement data generation unit 28 uses the angular relationship between the tomographic image and the puncture needle. As shown in FIG. 1, in the present embodiment, the angle formed by the puncture needle 17 with respect to the horizontal direction or the vertical direction of the tomographic image is determined by the puncture adapter 15. Therefore, the user inputs in advance an angle formed by the puncture needle 17 with respect to the horizontal direction or the vertical direction of the tomographic image from the operation unit 34. The displacement data generation unit 28 reads the angle formed by the puncture needle 17 with respect to the horizontal direction or the vertical direction of the tomographic image via the control unit 36 based on the operation in the operation unit 34. The displacement data generation unit 28 obtains a displacement image in which the color and brightness according to the direction of displacement of the biological tissue are mapped based on the association in which the puncture needle penetration direction is 0 °, and generates displacement image data. . The displacement data generation unit 28 may store a direction-to-color table in which the direction in which the puncture needle 17 travels is 0 ° and the color is associated with the direction of displacement of the living tissue.

  The puncture adapter 15 may be provided with a puncture needle direction sensor that outputs an angle formed by the puncture needle 17 with respect to the horizontal direction or the vertical direction of the tomographic image. In this case, the displacement data generation unit 28 reads the angle of the puncture needle 17 from the puncture needle direction sensor.

  In the ultrasonic diagnostic apparatus according to the present invention, the displacement of the living tissue is obtained based on a plurality of frames of tomographic image frame data. Therefore, in addition to transmitting and receiving ultrasonic waves to obtain a tomographic image, it is not necessary to further transmit and receive ultrasonic waves to obtain the displacement of living tissue. Therefore, the displacement of the living tissue is required more quickly than an ultrasonic diagnostic apparatus using the Doppler method as described in Patent Document 3, and an image that responds quickly to the movement of the living tissue can be displayed. That is, the displacement state of the living tissue can be displayed without significantly reducing the frame rate when generating the tomographic image frame data.

  FIG. 8 shows the configuration of an ultrasonic diagnostic apparatus according to the second embodiment. Whereas the ultrasonic diagnostic apparatus according to the first embodiment displays the displacement image superimposed on the tomographic image, the ultrasonic diagnostic apparatus according to the second embodiment displays an image showing the rotational characteristics of the biological tissue. Overlay the tomographic image. The rotation characteristic is obtained by, for example, performing a rotation operation (rot: rotation) that is a vector operation on the displacement as a vector quantity.

  As described above, the displacement data generation unit 28 generates displacement image data based on a plurality of tomographic image data for a plurality of frames going back to the past from the present time. The displacement data generation unit 28 outputs the displacement image data to the rotation characteristic data generation unit 52. The rotation characteristic data generation unit 52 obtains a rotation characteristic for each position based on the displacement of the living tissue at each position on the displacement image. For example, the rotation characteristic data generation unit 52 applies the rotation rot expressed by the following (Equation 1) to the displacement V of the living tissue at each position to obtain the rotation amount R. The amount obtained by the rotation is a vector amount having a component in the z-axis direction perpendicular to the xy plane. When the rotation amount R is positive, it means that the displacement of the living tissue includes a component in the left rotation direction when looking at the drawing surface. When the rotation amount R is negative, the rotation direction R is the right rotation direction when looking at the drawing surface. Means that the displacement of the living tissue contains the above component. Here, the rotation amount R is treated as a scalar amount representing the z-axis direction component.

  Here, the vector k is a unit vector in the z-axis positive direction. Although the right side of (Equation 1) is expressed by partial differentiation, since each pixel of the displacement image is discretely positioned, the difference calculation as shown in the following (Equation 2) is performed. FIG. 9 conceptually shows a part of the displacement image in order to explain the process for obtaining the rotation amount R. FIG. 9 shows 25 pixels whose x coordinate range is X (−2) to X (+2) and whose y coordinate range is Y (−2) to Y (+2). Here, the rotation amount in the target pixel 50 located at the position [X (0), Y (0)] will be described. When (Equation 1) is rewritten into a discrete expression, (Equation 2) is obtained, and the rotation amount at the target pixel 50 is obtained by (Equation 2).

Here, V _{y +} is a y-axis direction component of displacement indicated by a pixel adjacent to the target pixel 50 on the x-axis positive direction side, and V _y− is a pixel adjacent to the target pixel 50 on the x-axis negative direction side. The y-axis direction component of the displacement shown is shown. Further, V _{x +} is an x-axis direction component of displacement indicated by a pixel adjacent to the target pixel 50 on the y-axis positive direction side, and V _x− is a pixel adjacent to the target pixel 50 on the y-axis negative direction side. The x-axis direction component of displacement is shown. Δx indicates a pixel interval in the x-axis direction, and Δy indicates a pixel interval in the y-axis direction. When the pixel is a square, Δx and Δy have the same value. Further, since the rotation amount R is a relative value, Δx and Δy may be 1. In this case, the rotation amount R for the target pixel 50 at the position of [X (0), Y (0)] is obtained as R = (V _{y +} −V _y− ) − (V _{x +} −V _x− ). .

  Returning to FIG. 8, the rotation characteristic data generation unit 52 obtains the rotation amount for each position on the displacement image, and generates rotation characteristic image data indicating the rotation characteristic of the living tissue by color based on the rotation amount at each position. . That is, a process of obtaining a color corresponding to the polarity of the rotation amount for each pixel and associating it with each pixel, and a process of obtaining a luminance corresponding to the magnitude of the rotation amount for each pixel and associating it with each pixel are executed.

  The rotation characteristic data generation unit 52 may store a rotation direction versus color table in which a color is associated with the polarity of the rotation amount. In the rotation direction versus color table, for example, blue is associated with a positive rotation amount (left rotation direction in the xy plane) and negative rotation amount (right rotation direction in the xy plane). Match red. Furthermore, the rotation characteristic data generation unit 52 may store a rotation amount versus luminance table in which luminance is associated with the magnitude of the rotation amount. In the rotation amount table, for example, a larger luminance is associated with a larger rotation amount. Based on such association, the rotation characteristic data generation unit 52 obtains a rotation characteristic image obtained by mapping the color and luminance corresponding to the rotation amount to the pixel corresponding to each pixel of the tomographic image, and generates rotation characteristic image data. To do.

  As the tomographic image frame data is generated one after another in the tomographic image generating unit 20, the rotational characteristic data generating unit 52 generates rotational characteristic image data corresponding to each tomographic image frame data in time. To do. The rotation characteristic data generation unit 52 sequentially outputs the rotation characteristic image data generated over time to the image composition unit 22. The obtained rotation characteristic image data may be data for one image with respect to tomographic image frame data for a plurality of frames. In this case, the same rotational characteristic image data is temporally associated with the tomographic image frame data for a plurality of frames.

  Based on the tomographic image frame data and the rotational characteristic image data temporally corresponding to the tomographic image frame data, the image composition unit 22 converts the data indicating the tomographic / rotational image obtained by superimposing the rotational characteristic image onto the tomographic image. Generate as rotated image data and output to the monitor 30. The monitor 30 displays a tomographic / rotated image.

  As a result, an image obtained by superimposing the rotational characteristic image on the tomographic image is displayed on the monitor 30, and a change in the rotational characteristic of the living tissue is displayed on the monitor 30 together with the moving image of the tomographic image. That is, along with the movement of the living tissue, the rotation direction of the living tissue is indicated on the monitor 30 by color.

  FIG. 10 shows an example of an image displayed on the monitor 30. On the tomographic image 44, the rotation direction of the living tissue is indicated by a color together with the image 46 of the puncture needle. On the upper left of the monitor 30, a color map 48 showing the correspondence between the rotation direction of the living tissue and the color is shown.

  The color map 48 indicates that the fifth color is associated with the left rotation direction on the xy plane, and the sixth color is associated with the right rotation direction on the xy plane. For example, the fifth color and the sixth color are green and purple, respectively.

  In the image of FIG. 10, the rotation direction of the biological tissue is the right direction above the puncture needle image 46, and the rotation direction of the biological tissue is the left direction below the puncture needle image 46. . That is, it is shown that the puncture needle advances in the lower left direction, and the biological tissue is pulled so as to follow the puncture needle due to friction with the puncture needle, causing rotational distortion. From this, it is shown that the puncture needle has entered near the boundary between two regions in which the rotation direction of the living tissue is different. In general, in the vicinity of the tip of the puncture needle, the rotational distortion of the living tissue increases, and the rotational characteristics are exhibited with high brightness.

  As described above, in the tomographic image of the ultrasonic diagnostic apparatus, depending on the positional relationship between the probe and the puncture needle, the image of the puncture needle may become unclear and visibility may deteriorate, making it difficult to perform puncture. is there. According to the ultrasonic diagnostic apparatus of the present invention, the rotational characteristics of the biological tissue are shown to the user together with the tomographic image. In the rotation characteristic, it is considered that the puncture needle has entered the vicinity of the boundary between two regions where the rotation directions of the living tissue are different. Therefore, the user can grasp the path of the puncture needle from the rotation direction of the living tissue, and can easily perform puncture.

  The rotation direction of the living tissue may be indicated by a graphic such as an arrow together with the color. In this case, the rotation characteristic data generation unit 52 generates, as rotation characteristic image data, image data in which colors and figures are superimposed at corresponding positions on the tomographic image based on the rotation amount at the position where the figure is displayed. The rotation direction indicated by the figure corresponds to the polarity of the rotation amount. FIG. 11 shows an example of an image in which the rotation direction of the living tissue is indicated by an arrow indicating the rotation direction together with the color.

  The rotation direction may be indicated by other figures such as a plurality of triangles arranged in a circular shape in addition to the arrows. Further, the rotation direction of the living tissue may be indicated only by a figure regardless of the color. In this case, the rotation characteristic data generation unit generates, as the rotation characteristic image data, image data indicating the figure superimposed on the corresponding position on the tomographic image based on the rotation amount at the position where the figure is displayed.

  8 may generate, as tomographic / rotational / displacement image data, image data representing a tomographic / rotational / displacement image obtained by superimposing a displacement image on a tomographic / rotational image. In this case, the image composition unit 22 synthesizes the tomographic / rotated image data and the displacement image data so that the tomographic / rotated image can be seen through the displacement image.

  The tomographic / rotational / displacement image may be an image obtained by superimposing a rotational characteristic image on the above-described tomographic / displacement image. In this case, the image synthesizer 22 synthesizes the tomographic image data and the displacement image data to generate the tomographic / displaced image data, and then synthesizes the tomographic / displaced image data and the rotation characteristic image data.

  When generating the tomographic / rotational / displacement image data, the displacement data generation unit 28 may generate displacement image data indicating the displacement direction of the living tissue by a graphic regardless of the color, and output the displacement image data to the image composition unit 22. . Then, the rotation characteristic data generation unit 52 may generate rotation characteristic image data that indicates the rotation direction of the living tissue with a color and output the rotation characteristic image data to the image composition unit 22. As a result, the image composition unit 22 generates tomographic / rotational / displacement image data indicating the rotation direction of the biological tissue on the tomographic image by color and indicating the displacement direction of the biological tissue by a figure. The monitor 30 displays a tomography / rotation / displacement image.

  Further, when generating the tomographic / rotational / displacement image data, the displacement data generation unit 28 may generate displacement image data indicating the direction of displacement of the living tissue by color and output the displacement image data to the image composition unit 22. Then, the rotation characteristic data generation unit 52 may generate rotation characteristic image data indicating the rotation direction of the living tissue with a graphic and output the rotation characteristic image data to the image composition unit 22. As a result, the image composition unit 22 generates tomographic / rotational / displacement image data that indicates the direction of displacement of the biological tissue on the tomographic image by color and indicates the rotational direction of the biological tissue by a graphic. The monitor 30 displays a tomography / rotation / displacement image.

  Thus, by displaying the tomographic / rotational / displacement image, the direction of displacement of the biological tissue is shown to the user together with the rotational direction of the biological tissue. Thereby, the user can easily grasp the path of the puncture needle along with the displacement state and rotation characteristics of the living tissue.

  The displacement data generation unit 28 in the first and second embodiments may obtain the displacement subjected to the moving averaging process for each position on the tomographic image. In this case, the displacement data generation unit 28 obtains an average value of the displacement at each position for a predetermined number of pieces of displacement image data generated by itself retroactively from the present time, and moves this average value at each position on the tomographic image. The displacement after the averaging process. According to such a process, the change of the displacement shown on the monitor 30 is smoothed, and an image in which the past displacement image and the current displacement image are mixed is displayed. Therefore, even if the actual displacement of the living tissue suddenly becomes zero, the displacement of the living tissue shown on the monitor 30 gradually becomes zero. For example, when the displacement of the living tissue is indicated by color and luminance, when the movement of the puncture needle stops and the movement of the surrounding living tissue also stops, the luminance of the color representing the displacement of the living tissue gradually decreases, and gradually The color disappears.

  Note that the displacement data generation unit 28 may obtain a weighted average value of displacement at each position by multiplying each of the predetermined number of pieces of displacement image data generated by itself retroactively from the present time by an appropriate weighting coefficient. . In this case, the weighted average value of the displacement at each position on the displacement image is set as the displacement after the moving averaging process at each position on the tomographic image. For example, the pixel value at a certain position on the latest displacement image is P (0), the previous pixel value is P (1), the previous pixel value is P (2),. When the pixel value of −1 sheet before is P (n−1), the weighted average value A is expressed by the following (Equation 3).

  Here, Wi is a weighting coefficient, and by appropriately setting this value, the degree of reflecting past displacement images as afterimages is set. When Wi is 1, the weighted average value is the same as the normal average value.

  By using the moving averaging process, the change of the displacement image or the rotation characteristic image is smoothed. Therefore, even when the living tissue is suddenly displaced, an image that facilitates puncturing is displayed.

  10 beam control unit, 12 transmission unit, 14 probe, 16 subject, 18 reception unit, 20 tomographic image generation unit, 22 image composition unit, 24 frame data acquisition unit, 26 displacement measurement unit, 28 displacement data generation unit, 30 monitor , 32 Main unit, 34 Operation unit, 36 Control unit, 38-1, 38-2, 40-1, 40-2 Pixel, 42, 43, 48 Color map, 44 Tomographic image, 46 Puncture needle image, 50 Attention Pixel, 52 Rotation characteristic data generation unit.

The present invention is based on ultrasonic waves reflected by the living body tissue to be punctured, and the tomographic image generator for generating a tomographic image frame data, displacement data indicating the displacement state of the biological tissue displaced by puncturing, of a plurality of frames A displacement measurement unit that generates based on the tomographic image frame data, a displacement data generation unit that generates puncture displacement image data indicating a direction in which the living tissue is displaced by puncturing based on the displacement data, and the puncture displacement image an image based on the data, characterized in that and an image synthesizing unit to be displayed on the display unit superposed on the tomographic image based on the tomographic image frame data.

Preferably, the displacement data generation unit generates image data representing the displacement direction of the living tissue by color based on a predetermined correspondence between the displacement direction and color of the living tissue, and the puncture displacement image. Generate as data. Desirably, the displacement data generation unit acquires a puncture needle angle representing an angular relationship between the tomographic image and the puncture needle based on a user operation or using a puncture needle direction detection sensor, and Based on the needle angle, image data indicating the displacement direction of the living tissue with reference to the course direction of the puncture needle is generated as the puncture displacement image data. Preferably, the displacement measurement unit sequentially generates the displacement data with time based on the tomographic image frame data of a plurality of frames sequentially generated with time, and the displacement data generation unit An averaging process or a weighted averaging process is performed on the predetermined number of the retroactive displacement data to generate the puncture displacement image data, and the image synthesis unit sequentially outputs a plurality of the tomographic images as time elapses. While displaying on the display unit, an image based on the puncture displacement image data is displayed on the display unit so as to be superimposed on the temporally corresponding tomographic image. Also, preferably, the displacement data generation unit generates image data indicating the drawing element in the direction of displacement of the biological tissue as the biopsy shifted image data, the image synthesizing unit is based on the puncture-shifted image data image Is superimposed on the tomographic image and displayed on the display unit.

Further, the displacement data generation unit generates image data representing the direction component of a specific range of displacement of the biological tissue as the biopsy displacement image data.

Claims (7)

A tomographic image generation unit that generates tomographic image frame data based on the ultrasound reflected by the punctured biological tissue;
Based on the tomographic image frame data of a plurality of frames, a displacement data generation unit that generates displacement data indicating a displacement state of the biological tissue;
Based on the tomographic image frame data and the displacement data, together with the tomographic image, an image composition unit that displays the displacement state of the living tissue on a display unit;
An ultrasonic diagnostic apparatus comprising: The ultrasonic diagnostic apparatus according to claim 1,
The displacement data generation unit
Generating image data indicating the direction of displacement of the living tissue by a drawing element as the displacement data;
The image composition unit
An ultrasonic diagnostic apparatus, wherein an image based on the displacement data is superimposed on the tomographic image and displayed on the display unit. The ultrasonic diagnostic apparatus according to claim 2,
The displacement data generation unit
An ultrasonic diagnostic apparatus, wherein image data indicating a specific direction component of the displacement of the living tissue is generated as the displacement data. A tomographic image generation unit that generates tomographic image frame data based on the ultrasound reflected by the punctured biological tissue;
Based on the tomographic image frame data of a plurality of frames, a displacement data generation unit that generates displacement data indicating a displacement state of the biological tissue;
Based on the displacement data, a rotation characteristic data generation unit that generates rotation characteristic data indicating the rotation characteristic of the living tissue;
Based on the tomographic image frame data and the rotation characteristic data, an image synthesizing unit that displays the rotational characteristic of the living tissue together with the tomographic image on a display unit;
An ultrasonic diagnostic apparatus comprising: The ultrasonic diagnostic apparatus according to claim 4, wherein the displacement data generation unit is
Generating data indicating the displacement of the living tissue as the displacement data;
The rotation characteristic data generation unit
An ultrasonic diagnostic apparatus, wherein a rotation calculation is performed on the displacement of the living tissue, and a rotation component of the displacement of the living tissue is obtained as a rotation characteristic of the living tissue. The ultrasonic diagnostic apparatus according to claim 5,
The rotation characteristic data generation unit
Generating image data indicating a rotation direction indicated by the rotation component by a drawing element as the rotation characteristic data;
The image composition unit
An ultrasonic diagnostic apparatus, wherein an image based on the rotation characteristic data is displayed on the display unit so as to overlap the tomographic image. The ultrasonic diagnostic apparatus according to any one of claims 4 to 6,
The image composition unit
An ultrasonic diagnostic apparatus that displays the rotational characteristics and displacement state of the living tissue together with the tomographic image on the display unit.

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