JP2015131060A - ultrasonic diagnostic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly display an area where it is difficult to obtain a blood flow rate if any.SOLUTION: An area surrounded by a Doppler measurement ultrasonic beam 50 on a left end of a linear scan surface, a Doppler measurement ultrasonic beam 52 on a right end of a linear scan surface, a front wall 34 and a rear wall 36 is obtained as an ultrasonic beam passage area. A display image formation section obtains a substantially-triangle upper area surrounded by a front wall surface, an integration path 54 and the Doppler measurement ultrasonic beam on the right end as a first integration area 53, and further obtains a substantially-triangle lower area surrounded by a rear wall surface, an integration path 56, and the Doppler measurement ultrasonic beam 52 on the left end as a second integration area 55. The display image formation section obtains an area obtained by removing the first integration area 53 and the second integration area 55 from the ultrasonic beam passage area as an uncertain area 57. The uncertain area 57 is indicated by, for example, hatching.

Description

  The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to an apparatus for measuring a blood flow velocity.

  An ultrasonic diagnostic apparatus that measures the blood flow velocity of a subject by the Doppler method is widely used. In such an ultrasonic diagnostic apparatus, a blood flow velocity, which is a vector quantity, is displayed superimposed on a tomographic image with an arrow or the like, thereby diagnosing a circulatory organ such as a blood vessel or a heart. The component in the ultrasonic beam direction of the blood flow velocity is measured by the Doppler method, and the component in the direction orthogonal to the ultrasonic beam (orthogonal direction component) is obtained by calculation. As a technique for obtaining the orthogonal component of the blood flow velocity, there is one described in Patent Document 1.

FIG. 8 conceptually shows the speed detection process described as the prior art in Patent Document 1. In this process, the orthogonal component V _θ of the blood flow velocity is obtained from a continuous equation. First, for each ultrasonic beam direction, the ultrasonic beam direction component V _r of the blood flow velocity is measured by the Doppler method. Then, in the orthogonal path C orthogonal to the ultrasonic beam, the amount of change of the orthogonal direction component _{Vθ in} the orthogonal path direction is obtained using the ultrasonic beam direction component V _r , and further, the amount of change along the orthogonal path C Is integrated to obtain the orthogonal component _Vθ . The integration start position P is a position on the wall W of the circulatory organ such as the heart or blood vessel, and the initial value of integration is the orthogonal path direction component V _W of the motion speed at the integration start position P.

JP 2013-192643 A

In the speed detection process described above, the integration start position P in the orthogonal path C is a position on the wall surface W of the circulator, and the initial value of the integration is the orthogonal path direction component V _W of the motion speed of the integration start position P. . The integration start position P is obtained based on the tomographic image, and the initial value of integration is obtained based on a plurality of tomographic images that are sequentially acquired with time.

  However, depending on the tomographic image, the integration start position P and the initial value of the integration may not be obtained, and it may be difficult to obtain the orthogonal component of the blood flow velocity. If there is a region where it is difficult to determine the blood flow velocity, it may hinder diagnosis.

  An object of the present invention is to appropriately display a region where it is difficult to obtain a blood flow velocity.

  The present invention is based on a transmission / reception unit that transmits / receives an ultrasonic wave, a control unit that controls the transmission / reception unit to scan an ultrasonic beam transmitted / received by the transmission / reception unit, and an ultrasonic wave received by the transmission / reception unit. A tomographic image data generating unit that generates tomographic image data, a Doppler measuring unit that obtains an ultrasonic beam direction component of blood flow velocity for each ultrasonic beam direction based on the ultrasonic waves received by the transmitting / receiving unit, and time lapse A motion detection unit for determining the motion speed of the wall surface of the circulatory organ based on the plurality of tomographic image data, the ultrasonic beam direction component determined for each ultrasonic beam direction, and the motion speed of the wall surface For each ultrasonic beam direction, a velocity calculation unit that obtains an orthogonal direction component that is a blood flow velocity component in a direction orthogonal to the ultrasonic beam, and the plurality of tomographic images. With tomographic image based on at least one of the data, characterized in that it comprises a display processing unit that displays an indeterminate region where the orthogonal direction component could not be determined on the display unit.

  The transmission / reception unit in the present invention includes, for example, a probe and a transmission / reception circuit that outputs a transmission signal to the probe and acquires a reception signal from the probe. According to the present invention, an indeterminate region where the orthogonal component of the blood flow velocity has not been obtained is displayed. This facilitates cardiovascular diagnosis. The indeterminate region may be displayed so as to overlap the tomographic image. In this case, the region where the tomographic image and the indeterminate region overlap may be displayed so that one is transmitted through the other.

  In the ultrasonic diagnostic apparatus according to the present invention, preferably, the display processing unit displays a blood flow velocity on an ultrasonic beam scanning plane on the display unit based on the ultrasonic beam direction component and the orthogonal direction component. .

  According to the present invention, the blood flow velocity is displayed as a vector quantity including the ultrasonic beam direction component and the orthogonal direction component. Since the area where the orthogonal direction component is not obtained is displayed as an indeterminate area, it is possible to reduce misperception in cardiovascular diagnosis.

  In the ultrasonic diagnostic apparatus according to the present invention, preferably, the motion detection unit includes a detection unit that detects an image of the wall surface from each tomographic image indicated by the plurality of tomographic image data, and the detection unit that detects the tomographic image. A computing unit that obtains the motion speed of the wall surface based on the image of the wall surface.

  According to the present invention, the motion speed of the wall surface is determined using a technique for detecting the wall surface of the circulator. Thereby, for example, the processing for obtaining the orthogonal direction component of the blood flow velocity can be executed along with the processing for detecting the wall surface of the circulatory organ and displaying it on the tomographic image.

  In the ultrasonic diagnostic apparatus according to the present invention, preferably, the circulator includes a blood vessel, and the control unit sets the ultrasonic beam in a direction not perpendicular to a longitudinal direction of the blood vessel, and the ultrasonic beam is A linear scan is performed along the longitudinal direction of the blood vessel.

  According to the present invention, the ultrasonic beam is linearly scanned. As a result, data processing using the calculation method established in the orthogonal coordinate system becomes possible.

  In the ultrasonic diagnostic apparatus according to the present invention, preferably, the velocity calculation unit sets a value based on a motion speed of the wall surface as an initial value of integration, and sets a position on the wall surface as an integration start position for each ultrasonic beam. The display processing unit obtains the orthogonal direction component by performing integration along the orthogonal direction, and the integration processing start position on the wall surface is not determined in the region scanned with the ultrasonic beam, and the integration processing is performed. A region where the route does not pass is obtained as the uncertain region.

  According to the present invention, the indeterminate region is obtained together with the calculation for obtaining the orthogonal component of the blood flow velocity. This simplifies the process for obtaining the indeterminate area.

  According to the present invention, when there is a region where it is difficult to obtain the blood flow velocity, the region can be appropriately displayed.

It is a figure which shows the structure of the ultrasound diagnosing device which concerns on this invention. It is a figure which shows notionally the relationship between a tomographic image and a blood-flow velocity beam direction component. It is a figure which shows notionally the process in the integration based on a mass conservation law. It is a figure which shows the example of the image displayed on a display part. It is a figure which shows notionally the position where an auxiliary constant is set as an initial value of integration. It is a figure which shows notionally the tomographic image by a sector scan, and the ultrasonic beam for Doppler measurement. It is a figure which shows the example of the image displayed on a display part. It is a figure which shows notionally the speed detection process which concerns on a prior art.

  FIG. 1 shows an ultrasonic diagnostic apparatus according to an embodiment of the present invention. The ultrasonic diagnostic apparatus scans an ultrasonic beam transmitted / received to / from the subject, displays a tomographic image based on the received ultrasonic wave, and measures a blood flow velocity in the blood vessel of the subject. indicate. The blood flow velocity is a vector quantity having a direction and a magnitude, and is displayed by a figure such as an arrow, a combination of color and luminance, or two component values.

  In the measurement, the probe 10 is brought into contact with the surface of the subject. The probe 10 includes a plurality of ultrasonic transducers. The transmission / reception circuit 12 transmits a transmission signal to each ultrasonic transducer of the probe 10 based on control by the control unit 14. As a result, ultrasonic waves are transmitted from the probe 10. When the ultrasonic waves reflected in the subject are received by the ultrasonic transducers of the probe 10, each ultrasonic transducer outputs an electrical signal to the transmission / reception circuit 12. The transmission / reception circuit 12 performs level adjustment and the like on the electrical signal output from each ultrasonic transducer and performs phasing addition.

  The ultrasonic diagnostic apparatus displays a tomographic image by B-mode measurement as follows. The transmission / reception circuit 12 forms a transmission ultrasonic beam in the probe 10 under the control of the control unit 14, and scans the subject with the transmission ultrasonic beam. The transmission / reception circuit 12 generates a reception signal by phasing and adding the electrical signals output from the ultrasonic transducers of the probe 10 under the control of the control unit 14, and outputs the reception signal to the tomographic image data generation unit 16. As a result, a reception ultrasonic beam is formed in the transmission / reception circuit 12, and a reception signal corresponding to the reception ultrasonic beam is output from the transmission / reception circuit 12 to the tomographic image data generation unit 16.

  The tomographic image data generation unit 16 generates tomographic image data based on the received signal obtained for each ultrasonic beam direction, and outputs it to the display processing unit 20. The display processing unit 20 displays a tomographic image based on the tomographic image data on the display unit 30.

  The ultrasonic diagnostic apparatus obtains the blood flow velocity by the following Doppler measurement and displays the blood flow velocity on the display unit 30 so as to be superimposed on the tomographic image. Transmission / reception of ultrasonic waves for B-mode measurement and transmission / reception of ultrasonic waves for Doppler measurement are performed in time division, and B-mode measurement and Doppler measurement are performed in time division.

  The transmission / reception circuit 12 forms a transmission ultrasonic beam in the probe 10 under the control of the control unit 14, and scans the subject with the transmission ultrasonic beam. In addition, the transmission / reception circuit 12 generates a reception signal by phasing and adding the electrical signals output from the ultrasonic transducers of the probe 10 under the control of the control unit 14, and outputs the reception signal to the Doppler measurement unit 18. As a result, a reception ultrasonic beam is formed in the transmission / reception circuit 12, and a reception signal corresponding to the reception ultrasonic beam is output from the transmission / reception circuit 12 to the Doppler measurement unit 18 as a reception signal for Doppler measurement. The Doppler measurement unit 18 analyzes the Doppler shift frequency of the received signal obtained for each ultrasonic beam direction, and the ultrasonic beam direction component (hereinafter referred to as blood flow velocity) of the blood flow velocity at each position on each ultrasonic beam. The beam direction component is obtained. The Doppler measurement unit 18 outputs the blood flow velocity beam direction component to the display processing unit 20 together with the coordinate value of each position for which the blood flow velocity beam direction component has been obtained.

  FIG. 2 conceptually shows the relationship between the tomographic image 32 and the blood flow velocity beam direction component 40. In this example, the ultrasonic beam 42 formed by the probe 10 is inclined by an angle φ with respect to the positive x-axis direction, and the ultrasonic beam 42 is linearly scanned in the y-axis direction. In the tomographic image 32, images of the front wall 34 and the rear wall 36 of the blood vessel appear. A region sandwiched between the front wall 34 and the rear wall 36 is a blood vessel lumen 38. The ultrasonic beam is in a direction that is not perpendicular to the longitudinal direction of the blood vessel, and is linearly scanned along the longitudinal direction of the blood vessel. In FIG. 2, each blood flow velocity beam direction component 40 obtained by Doppler measurement is conceptually indicated by an arrow.

  The Doppler measurement unit 18 in FIG. 1 determines the blood flow velocity beam direction component, but cannot determine the component in the direction orthogonal to the ultrasonic beam. Therefore, the display processing unit 20 performs a plurality of tomographic image data sequentially output from the tomographic image data generation unit 16 over time by integration based on the law of conservation of mass described below, and blood flow velocity beam direction components at each position. Based on the above, the component of the blood flow velocity in the direction orthogonal to the ultrasonic beam (hereinafter referred to as the orthogonal component) is obtained.

  FIG. 3 conceptually shows processing in integration based on the law of conservation of mass. In the integration based on the law of conservation of mass, the α axis is determined in the ultrasonic beam direction, and the β axis is determined in the direction orthogonal to the ultrasonic beam. In the example shown in FIG. 3, the ultrasonic beam direction is inclined by an angle φ with respect to the x-axis direction (vertical direction).

Perpendicular direction component V _beta is, alpha axial variation of the blood flow velocity beam direction component V _alpha a (∂V _{α /} ∂α), obtained by integrating the beta axially. That is, the orthogonal direction component V _β (Q) at the point Q is expressed by the following (Equation 1).

Here, the integration start position P is a position on the front wall surface or the rear wall surface in the region of interest 44. When the position on the front wall can be set as the integration start position, the point on the front wall can be set as the integration start position P, and the position on the rear wall can be set as the integration start position. A point on the rear wall may be set as the integration start position P. The right side of equation (1) are depicted by partial differential and integral, the actual operation is carried out by adding the sum of the difference V _alpha at each position on the integration path.

For example, the orthogonal direction component V _β (Q1) at the point Q1 in FIG. 3 has the position P1 on the rear wall surface as the integration start position, and the blood flow velocity beam direction along the integration path 46 in the β-axis direction to the point Q1. It is obtained by integrating the amount of change in the α-axis direction of the component V _α . Further, the orthogonal direction component V _β (Q2) at the point Q2 has the position P2 on the front wall surface as the integration start position, and the blood flow velocity beam direction component V _α along the integration path 48 in the β-axis direction to the point Q2. Is obtained by integrating the amount of change in the α-axis direction.

When the display processing unit 20 in FIG. 1 obtains these integral values, the β-axis direction component V _β (P) of the motion speed at the integration start position P is required as an initial value of integration. Therefore, the display processing unit 20 obtains the β-axis direction component of the motion speed at the integration start position P as an initial value of integration based on a plurality of tomographic image data sequentially output from the tomographic image data generation unit 16 over time. . Then, integration based on the law of conservation of mass is performed using the obtained initial value of integration, and the orthogonal direction component V _β (Q) at each position Q in the blood vessel lumen 38 is obtained.

  A specific process in which the display processing unit 20 obtains the blood flow velocity based on the integration based on the law of conservation of mass and graphically displays the blood flow velocity on the display unit 30 together with the tomographic image will be described. As a premise of this process, the control unit 14, the transmission / reception circuit 12, the probe 10, and the tomographic image data generation unit 16 repeatedly execute a process of generating tomographic image data by B-mode measurement. As a result, the tomographic image data generation unit 16 sequentially outputs a plurality of tomographic image data to the display processing unit 20 over time.

  The display processing unit 20 displays the tomographic image as a moving image on the display unit 30 based on the tomographic image data sequentially output from the tomographic image data generation unit 16. The display processing unit 20 may display the tomographic image as a still image on the display unit 30 based on one tomographic image data.

  The blood vessel region setting unit 28 includes a user interface such as a trackball and a mouse. The blood vessel region setting unit 28 sets a region of interest for obtaining the blood flow velocity on the tomographic image displayed on the display unit 30 based on a user operation referring to the tomographic image displayed on the display unit 30.

  The motion detection unit 22 detects a blood vessel wall surface image from each tomographic image indicated by a plurality of tomographic image data, and the blood vessel wall surface motion speed is determined based on the blood vessel wall surface image detected from each tomographic image. It has a calculation part to obtain. That is, the motion detection unit 22 detects the image of the blood vessel wall surface in the region of interest on the tomographic image based on the tomographic image data, and sets the integration start position in the detected blood vessel wall surface image. Then, based on a plurality of tomographic image data for a plurality of images going back to the past, for example, two tomographic image data generated before and after the time, the β-axis direction component of the movement speed at the integration start position is initialized. Calculate as a value. The speed calculation unit 24 performs integration based on the law of conservation of mass using the obtained initial value of integration, and obtains the orthogonal component at each position on the integration path.

  The motion detection unit 22 sets a plurality of integration start positions along each of the front wall surface and the rear wall surface, and the speed calculation unit 24 performs integration based on the law of conservation of mass from each integration start position. Thereby, the orthogonal component at each position of the blood vessel lumen is obtained. The position where two orthogonal components are obtained by the integration based on the law of conservation of mass for the integration start position set on the front wall and the integration based on the law of conservation of mass for the integration start position set on the rear wall Can occur. For such a position, as described in Patent Document 1, two orthogonal direction components may be obtained by weighted addition of two orthogonal direction components.

  By such processing, the blood flow velocity represented by the blood flow velocity beam direction component and the orthogonal direction component is obtained for each position of the blood vessel lumen. The display image forming unit 26 generates blood flow velocity data that graphically displays the blood flow velocity at each position of the blood vessel lumen, and displays an image in which a graphic indicating the blood flow velocity is superimposed on the tomographic image on the display unit 30.

  The control unit 14 controls the transmission / reception circuit 12 to repeatedly linearly scan an ultrasonic beam for Doppler measurement. Along with this, the motion detector 22 and the velocity calculator 24 sequentially obtain the blood flow velocity at each position of the blood vessel lumen for each linear scan. The display image forming unit 26 sequentially generates blood flow velocity data, and sequentially displays on the display unit 30 an image in which a figure indicating the blood flow velocity is superimposed on the tomographic image. Thus, the blood flow velocity is displayed on the display unit 30 along with the blood vessel motion.

  As described above, the motion detection unit 22 detects an image of the blood vessel wall surface. Based on the processing result of the motion detection unit 22, the display image forming unit 26 may execute processing for emphasizing and displaying the image of the blood vessel wall surface, such as displaying the image of the blood vessel wall surface with a line on the tomographic image.

  It should be noted that the blood flow velocity cannot be obtained for the region where the ultrasonic beam for Doppler measurement has not passed. Therefore, the blood flow velocity is not displayed in such a region. Also, even in the region where the ultrasonic beam for Doppler measurement has passed, the integration start position of the integration based on the law of conservation of mass is not determined, and the orthogonal component cannot be obtained for the region where the integration path has not passed. . Therefore, the display image forming unit 26 determines an area where the integration start position is not determined and the integration path has not passed as an indeterminate area, and displays the indeterminate area on the display unit 30.

  A process in which the display image forming unit 26 obtains the indeterminate area will be described. As described above, the Doppler measurement unit 18 outputs the coordinate value of each position for which the blood flow velocity beam direction component has been obtained, and the display image forming unit 26 determines the superordinate value based on the coordinate value of each position. The acoustic beam passage area is obtained.

  Next, the display image forming unit 26 obtains an integration region through which an integration path of integration based on the law of conservation of mass has passed. This process is performed by acquiring information representing each integration path from the speed calculation unit 24. The display image forming unit 26 obtains an area obtained by removing the integration area from the ultrasonic beam passage area as an indeterminate area.

  FIG. 4 illustrates an image displayed on the display unit 30. In this example, the region surrounded by the Doppler measurement ultrasonic beam 50 at the left end of the linear scanning surface, the Doppler measurement ultrasonic beam 52 at the right end of the linear scanning surface, the front wall 34 and the rear wall 36 is an ultrasonic beam passage region. As required.

  Further, the display image forming unit 26 obtains an upper substantially triangular area surrounded by the front wall surface, the integration path 54, and the rightmost Doppler measurement ultrasonic beam 52 as the first integration area 53. Here, the integration path 54 is an integration path passing through the intersection of the leftmost Doppler measurement ultrasonic beam 50 and the front wall surface. Further, the display image forming unit 26 obtains a lower triangular area surrounded by the rear wall surface, the integration path 56, and the leftmost Doppler measurement ultrasonic beam 50 as the second integration area 55. Here, the integration path 56 is an integration path passing through the intersection of the rightmost Doppler measurement ultrasonic beam 52 and the rear wall surface.

  The display image forming unit 26 obtains a region obtained by removing the first integration region 53 and the second integration region 55 from the ultrasonic beam passage region as an indeterminate region 57. In FIG. 4, the uncertain region 57 is indicated by hatching.

  The display image forming unit 26 graphically displays the blood flow velocity on the display unit 30 in the first integration region 53 and the second integration region 55 by superimposing the blood flow velocity on the tomographic image. The display image forming unit 26 does not display the blood flow velocity in the indeterminate region 57.

  If the distance between the Doppler measurement ultrasonic beams at both ends is sufficiently wide, or if the angle between the blood vessel stretching direction and the direction of each Doppler measurement ultrasonic beam is sufficiently small, an indeterminate region does not occur. The indeterminate region is not displayed on the display unit 30. Here, the right and left end Doppler measurement ultrasonic beams are displayed on the display unit 30, but these Doppler measurement ultrasonic beams may not be displayed on the display unit 30.

  According to such processing, an indeterminate region in which the orthogonal component of the blood flow velocity cannot be obtained is clearly displayed on the display unit 30. This facilitates cardiovascular diagnosis.

  Next, an application example of integration based on the law of conservation of mass will be described. In the integration based on the above-mentioned law of conservation of mass, the orthogonal direction component is not obtained for the uncertain region in the ultrasonic beam passage region. In this application example, an orthogonal direction component is obtained for an indeterminate region by using a preset auxiliary constant as an initial value of integration.

  In FIG. 5, the position where the auxiliary constant is set as the initial value of integration is conceptually represented by a line segment AB. The line segment AB corresponds to a portion of the right end Doppler measurement ultrasonic beam 52 that partitions the indeterminate region 57. The motion detector 22 sets a plurality of integration start positions along the line segment AB, and sets an auxiliary constant as an initial value of integration at each integration start position. For each auxiliary constant, for example, an appropriate value is set by a user operation. In addition, each auxiliary constant may be set based on a statistical value such as an average value or median value of the blood flow velocity obtained in the first integration region 53 or the second integration region 55. The speed calculation unit 24 performs integration based on the law of conservation of mass along the path in the β-axis direction for each integration start position on the line segment AB, and obtains an orthogonal component at each position on each integration path.

  By such processing, the blood flow velocity represented by the blood flow velocity beam direction component and the orthogonal direction component is obtained for each position of the indeterminate region 57. The display image forming unit 26 generates blood flow velocity data that graphically displays the blood flow velocity at each position in the indeterminate region 57, and displays an image in which the graphic indicating the blood flow velocity is superimposed on the tomographic image on the display unit 30. .

  In FIG. 5, the blood flow velocity obtained for the indeterminate region 57 is indicated by an arrow. The display image forming unit 26 may display the hatching of the indeterminate region 57 so that the arrow indicating the blood flow velocity is seen through.

  According to such processing, by using the auxiliary constant, the orthogonal direction component can be obtained for the uncertain region, and the blood flow velocity can be obtained. Furthermore, an indeterminate region where it is difficult to determine the blood flow velocity can be clearly indicated to the user.

  Next, an embodiment in which an ultrasonic beam is sector-scanned will be described. Since the configuration of the ultrasonic diagnostic apparatus is the same as that in the case of performing linear scanning, FIG. 1 is used here. Sector scanning changes the direction of the ultrasonic beam by oscillating the ultrasonic beam. The control unit 14 controls the transmission / reception circuit 12 to form the B-mode measurement ultrasonic beam and the Doppler measurement ultrasonic beam in the probe 10 in a time-sharing manner, and sector-scans each ultrasonic beam with respect to the subject. .

  The tomographic image data generation unit 16 generates tomographic image data based on the reception signal output from the transmission / reception circuit 12 in response to sector scanning, and outputs the generated tomographic image data to the display processing unit 20. The Doppler measurement unit 18 obtains a blood flow velocity beam direction component at each position on each ultrasonic beam based on the reception signal output from the transmission / reception circuit 12 in response to the sector scan, and outputs it to the display processing unit 20. .

  FIG. 6 conceptually shows a tomographic image 58 by sector scanning and an ultrasonic beam 59 for Doppler measurement. This tomographic image 58 shows the left atrium 60 and the left ventricle 62 of the heart. A portion indicated by a broken line in the left ventricle 62 is a portion where an image was not obtained due to poor measurement conditions. In FIG. 6, the direction of the ultrasonic beam is the r-axis direction, and the direction orthogonal to the ultrasonic beam is the θ-axis direction.

The Doppler measurement ultrasonic beam 59 oscillates around the transmission / reception point O by sector scanning. In the Doppler measurement unit 18, the blood flow velocity beam direction component V _r (r-axis direction component) at each position on the ultrasonic beam 59 in each direction is obtained.

The orthogonal component V _θ (θ-axis component) at each position on the ultrasonic beam 59 is obtained by integration based on the law of conservation of mass. The motion detection unit 22 sets a plurality of integration start positions along the wall surface of the left atrium 60 and the wall surface of the left ventricle 62 based on the tomographic image data. Then, based on a plurality of tomographic image data for a plurality of images going back to the past, for example, two tomographic image data generated before and after the time, the motion speed of the integration start position set on the tomographic image 58 is determined. The θ-axis direction component is obtained as the initial value of integration. Point P in FIG. 6 indicates one of a plurality of integration start positions.

The speed calculation unit 24 performs integration based on the law of conservation of mass in the θ-axis direction with respect to the integration start position P, and obtains the orthogonal direction component V _θ (Q) at the point Q on the integration path. Specifically, the orthogonal component V _θ (Q) at the point Q is expressed by the following (Equation 2).

The integration initial value V _θ (P) based on the law of conservation of mass is a θ-axis direction component of the motion speed at the integration start position P, and is obtained by the motion detection unit 22 as described above. The right side of (Expression 2) is expressed by partial differentiation and integration, but the actual calculation is performed by adding and summing the differences of (r · V _r ) at each position on the integration path.

  By such processing, the blood flow velocity is obtained for each position of the left atrium 60 and the left ventricle 62. The display image forming unit 26 generates blood flow velocity data for displaying the blood flow velocity at each position of the left atrium 60 and the left ventricle 62 with a graphic such as an arrow, and an image obtained by superimposing a graphic indicating the blood flow velocity on the tomographic image. Is displayed on the display unit 30.

  The display image forming unit 26 displays the indeterminate region 66 on the display unit 30 by the same processing as that in the embodiment that performs the linear scanning described above. In the example of FIG. 6, the indeterminate region 66 is indicated by hatching. The indeterminate region 66 is a region in which integration based on the law of conservation of mass has not been performed because images of the left and right inner wall surfaces of the left ventricle 62 were not obtained in the tomographic image 58.

  In the present embodiment in which sector scanning is performed, as in the embodiment in which linear scanning is performed, an orthogonal constant component in the indeterminate region 66 may be obtained by setting an auxiliary constant as an initial value of integration.

  FIG. 7 shows an example of an image displayed on the display unit 30. The display unit 30 displays images of the left atrium 60 and the left ventricle 62. In the left atrium 60 and the left ventricle 62, the blood flow velocity is indicated by a color 68. For the color 68, for example, the direction away from the probe is blue, the direction approaching the probe is red, and the other directions are intermediate colors. Moreover, you may enlarge the brightness | luminance at the time of displaying the color 68, so that the magnitude | size of the blood flow velocity is large. The indeterminate region 66 is indicated by hatching.

  According to the ultrasonic diagnostic apparatus of the present invention, an indeterminate region where the blood flow velocity cannot be completely obtained is clearly indicated on the display unit. This can reduce false positives in cardiovascular diagnosis.

DESCRIPTION OF SYMBOLS 10 Probe, 12 Transmission / reception circuit, 14 Control part, 16 Tomographic image data generation part, 18 Doppler measurement part, 20 Display processing part, 22 Motion detection part, 24 Speed calculation part, 26 Display image formation part, 28 Blood vessel area | region setting part, 30 Display part, 32,58 Tomographic image, 34 Front wall, 36 Back wall, 38 Blood vessel lumen, 40 Blood flow velocity beam direction component, 42, 50, 52 Ultrasound beam, 44 Region of interest, 46, 48, 54, 56, 64 integration path, 53 first integration region, 55 second integration region, 57, 66 uncertainty region, 60 left atrium, 62 left ventricle.

Claims (5)

A transmission / reception unit for transmitting and receiving ultrasonic waves;
A controller that controls the transceiver to scan an ultrasonic beam transmitted and received by the transceiver;
A tomographic image data generation unit that generates tomographic image data based on the ultrasonic waves received by the transceiver unit;
Based on the ultrasonic wave received by the transceiver unit, a Doppler measurement unit for obtaining an ultrasonic beam direction component of blood flow velocity for each ultrasonic beam direction;
Based on a plurality of tomographic image data generated with the passage of time, a motion detector that determines the motion speed of the wall surface of the circulator
Based on the ultrasonic beam direction component obtained for each ultrasonic beam direction and the motion velocity of the wall surface, the blood flow velocity component in the direction orthogonal to the ultrasonic beam is obtained for each ultrasonic beam direction. A speed calculation unit for obtaining a certain orthogonal component;
A display processing unit that displays an indeterminate region in which the orthogonal direction component is not obtained together with a tomographic image based on at least one of the plurality of tomographic image data on a display unit;
An ultrasonic diagnostic apparatus comprising: The ultrasonic diagnostic apparatus according to claim 1,
The display processing unit
An ultrasonic diagnostic apparatus, wherein a blood flow velocity on an ultrasonic beam scanning plane is displayed on the display unit based on the ultrasonic beam direction component and the orthogonal direction component. The ultrasonic diagnostic apparatus according to claim 1 or 2,
The motion detector is
A detection unit for detecting an image of the wall surface from each tomographic image indicated by the plurality of tomographic image data;
An ultrasonic diagnostic apparatus comprising: an arithmetic unit that obtains a motion speed of the wall surface based on the image of the wall surface detected from each tomographic image. The ultrasonic diagnostic apparatus according to any one of claims 1 to 3,
The circulatory system includes blood vessels;
The controller is
An ultrasonic diagnostic apparatus, wherein the ultrasonic beam is set in a direction that is not perpendicular to the longitudinal direction of the blood vessel, and the ultrasonic beam is linearly scanned along the longitudinal direction of the blood vessel. The ultrasonic diagnostic apparatus according to any one of claims 1 to 4,
The speed calculator is
The value based on the motion speed of the wall surface is an initial value of integration, the position on the wall surface is set as an integration start position, and the orthogonal direction component is obtained by performing integration along the direction orthogonal to each ultrasonic beam,
The display processing unit
An ultrasonic diagnostic apparatus characterized in that, in an area scanned with the ultrasonic beam, an integration start position on the wall surface is not determined and an area through which the integration path does not pass is obtained as the indeterminate area.

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