JP2742218B2 - Ultrasound diagnostic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called ultrasonic Doppler diagnostic apparatus for measuring a moving speed of a subject tissue using ultrasonic information and diagnosing a moving state of the subject tissue.

[0002]

2. Description of the Related Art Conventionally, an ultrasonic Doppler diagnostic apparatus as disclosed in Japanese Patent Application Laid-Open No. 2-193650 has been known as an ultrasonic diagnostic apparatus for diagnosing the motion state of a subject.
This ultrasonic Doppler diagnostic device is a device that displays a two-dimensional distribution of the motion speed of a subject in real time in color. For example, when diagnosing a heart, it performs a relatively high-speed motion using a high-pass filter. A Doppler signal related to blood is extracted.

Further, by using a low-pass filter, a Doppler signal relating to a living tissue such as a heart valve or a myocardium moving at a low speed is extracted, and the low-speed Doppler information and the high-speed Doppler information are selectively extracted. Can be displayed.

[0004] By using such an ultrasonic Doppler diagnostic apparatus, the moving speed of a specific region of a subject moving at various speeds is measured, and an abnormality such as cardiac function is diagnosed.

FIG. 6 shows a display example of a motion velocity distribution of a living tissue by a conventional ultrasonic Doppler diagnostic apparatus. In the figure, the living tissue is the myocardium of the heart.

During the diastole of the heart, the myocardial tissue 12f in a region near the probe 10 moves in a direction approaching the probe 10, and the myocardial tissue 12b in a region far from the probe 10 moves. It is moving in a direction away from the probe 10.
For example, in the case of color display similar to the conventional blood flow display, the myocardial tissue 12f approaching the probe 10 is displayed in red, and the myocardial tissue 12b moving away from the probe 10 is displayed in blue.

On the other hand, during the systole of the heart (not shown), the myocardial tissue 12f in a region near the probe 10 is displayed in blue because it moves in a direction away from the probe 10, and Since the myocardial tissue 12b in the far region moves in the direction approaching the probe 10, it is displayed in red.

[0008]

However, the subject has a three-dimensional structure. For example, in the heart, since the whole heart is beating while being twisted, it is necessary to accurately diagnose abnormalities such as cardiac function. There is a need to detect the motion of the entire heart and detect the dilation / contraction motion of the myocardium or the like relative to the motion of the entire heart.

On the other hand, in the conventional ultrasonic diagnostic apparatus, no consideration has been given to detecting the overall movement of the subject and measuring and diagnosing the relative movement of each living tissue excluding this movement. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and detects the overall motion state of a subject, displays the relative motion of the living tissue excluding the overall motion, and displays the relative motion of the subject. It is an object of the present invention to provide an ultrasonic diagnostic apparatus capable of accurately diagnosing an image.

[0011]

To achieve the above object, an ultrasonic diagnostic apparatus according to the present invention has the following features.

In an ultrasonic diagnostic apparatus for transmitting and receiving an ultrasonic beam to and from an object and displaying an ultrasonic image based on the received wave, the velocity of movement of each point of the object tissue in the ultrasonic beam axis direction from the received wave Calculating means for determining the contour of the subject tissue for each frame, a reference point for determining a reference point in an area defined by the contour, and a reference point for determining a moving speed of the reference point between frames. Arithmetic processing means, speed correction means for calculating the relative movement speed of each point of the subject tissue with respect to the reference point, based on the movement speed of the reference point and the movement speed of each point of the subject tissue, Display means for displaying a relative movement speed of each point of the subject tissue with respect to the reference point.

The display means displays the relative movement speed of each point of the subject tissue in a two-dimensional manner, and the relative movement speed of each point of the subject tissue moving in a direction approaching the reference point has a predetermined color. The relative movement speed of each point of the subject tissue moving in a direction away from the reference point is represented by a predetermined color different from the relative movement speed of the subject tissue moving in the approaching direction. It is characterized by.

[0014] The display means displays the magnitude of the relative movement speed by luminance or a different hue.

[0015] The reference point is a center of gravity of the area.

The velocity correcting means subtracts the moving velocity component of the reference point from the moving velocity of each point of the subject tissue in the direction of the ultrasonic beam axis to obtain a velocity component of each point of the subject tissue. Velocity component calculation means, coefficient calculation means for obtaining a correction coefficient for the speed component, based on an angle formed by the ultrasonic beam axis and a straight line connecting the reference point and each point of the subject tissue, A relative speed calculating means for calculating a relative motion speed of each point of the subject tissue with respect to the reference point based on a speed component and the correction coefficient.

The reference point calculation processing means obtains a center of gravity element for each of a plurality of minute area areas within the area defined by the contour of the tissue, and obtains a center of gravity within the area for each frame based on the center of gravity element. Center of gravity calculation means,
And a center-of-gravity speed calculating means for obtaining the amount of movement of the center of gravity within the region between each frame and calculating the moving speed of the center of gravity based on the amount of movement.

[0018]

According to the ultrasonic diagnostic apparatus of the present invention, a contour of a living tissue, for example, a boundary between a heart muscle and a heart chamber is detected for each frame, and a so-called closed region such as a heart chamber defined by the contour is detected. And the moving speed of the reference point between each frame can be automatically detected. Further, based on the moving speed of the reference point, a relative movement speed of the living tissue with respect to the reference point is displayed.

Therefore, the movement of the whole subject is removed, and the movement speed unique to each living tissue can be detected, so that abnormal movement of the living tissue due to myocardial infarction or the like can be accurately diagnosed.

Further, the determined relative movement speed of each point of the tissue moving in the direction approaching the reference point is displayed in a predetermined color, and the relative movement speed of each point of the tissue moving in the direction moving away from the reference point is expressed by: If the color is displayed in a color different from the relative motion speed of the subject tissue moving in the approaching direction, for example, when the subject is a heart, during the systole of the heart, the myocardial tissue is not affected by the distance from the probe. Because it moves in the direction approaching the reference point,
The entire myocardial region on the screen is displayed in the same color. Conversely, during the diastole of the heart, the myocardial tissue moves in a direction away from the reference point, and thus is displayed in the same color different from the systole.

Therefore, the movement time phase of the subject can be easily confirmed. If the display luminance is changed according to the magnitude of the relative movement speed, a more detailed movement state at each point of the subject tissue can be measured and diagnosed.

When the reference point of an area defined by the contour, for example, a closed area such as a heart chamber, is set as the center of gravity, the coincidence between the center of gravity and the movement reference point of the subject is high. Therefore, if the relative movement speed of the living tissue with respect to the center of gravity is obtained, the movement state unique to the living tissue can be diagnosed more accurately.

Further, when the reference point of the closed area of the subject is set as the center of gravity, the center of gravity element in each small area area in the closed area is obtained, and the center of gravity element is added. The center of gravity of the whole can be obtained. The velocity of the center of gravity can be easily given by calculating the amount of movement of the center of gravity in the closed region between each frame.

Accordingly, the information on the center of gravity can be obtained by automatic calculation, and the operator of the ultrasonic diagnostic apparatus can specify the reference point on the display screen when obtaining the relative movement speed of the living tissue with respect to the reference point. No special work is required. Therefore, diagnosis can be performed in a short time and accurate diagnosis can be performed because relative motion speed information with small variations and high reliability is displayed.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a conceptual diagram showing a method for obtaining a relative movement speed of a subject tissue with respect to a reference point according to an embodiment of the present invention. The probe 10 is a general sector scan probe that transmits and receives an ultrasonic beam to and from a subject. When the subject is a heart, the blood flow area 16 (so-called predetermined closed area) is a heart cavity area surrounded by myocardial tissue and filled with blood. The center of gravity G is
It is a reference point of the blood flow area 16 and is 1
Moving speed between the frames is shown as the center of gravity velocity vector v _g.

Next, the configuration of the ultrasonic Doppler diagnostic apparatus of the present invention will be described with reference to FIGS. Here, FIG.
FIG. 3 is a diagram illustrating a configuration of a center-of-gravity calculation processing unit 40 in FIG. 2.

As shown in FIG. 2, the scanning control unit 54 receives a timing signal from the timing signal
The control unit controls the transmission and reception of ultrasonic waves in the probe 10 via the transmission and reception unit 20.

A detection unit 24 is connected to the other output side of the transmission / reception unit 20 via an amplification unit 22.
4 is connected to an A / D converter 26. Detection unit 2
Reference numeral 4 denotes a configuration for extracting two-dimensional tomographic image information based on amplitude information of a received wave from a subject.

The output side of the A / D converter 26 is connected to a center-of-gravity calculation processor 40, to which the two-dimensional tomographic image information of the subject output from the A / D converter 26 is input.

The center-of-gravity calculation processing unit 40 has a configuration as shown in FIG. 3 and is a calculation processing unit for calculating the center-of-gravity information.

The area calculating section 42 shown in FIG.
Based on the two-dimensional tomographic image information obtained in step 4, the calculation unit calculates the area S of the blood flow area in FIG. 4 and the small area ΔSi of the blood flow area in each frame.

The center-of-gravity calculating section 44 includes an area calculating section 42
, And calculates the center of gravity G of the blood flow area as the center of gravity position vector Rg based on the area S and the small area ΔSi. The center of gravity speed calculation unit 46 is connected to the center of gravity calculation unit 44 and This is a calculation unit for calculating the moving speed of the center of gravity G.

The center-of-gravity velocity calculation unit 46, the information of the center-of-gravity velocity v _g, and outputs the velocity component calculating unit 62 of the velocity corrector 60,
The center-of-gravity calculating unit 44 calculates the information of the center of gravity G by using the center-of-gravity position vector R
The value is output to the coefficient calculation unit 64 of the speed correction unit 60 as g.

A quadrature detection section 30 is connected to the other output side of the transmission / reception section 20 in FIG. Quadrature detector 30
Is a detection unit connected to the transmission / reception unit 20 for obtaining a Doppler signal from the ultrasonic signal received by the probe 10 and performing quadrature detection. The quadrature detection is performed by multiplying the output reference signals having different phases by 90 degrees.

The low-pass filter 32 connected to the quadrature detector 30 converts a Doppler signal composed of two signals of a real component and an imaginary component obtained by the quadrature detection from
This is a so-called low-pass filter for extracting only a low-speed (low-frequency band) Doppler signal. Here, if the subject is a heart, the Doppler signal in the low frequency band is a living tissue such as a myocardium.
A high-speed (high-frequency band) Doppler signal caused by blood in the myocardial tissue 12d is removed, and a Doppler signal in the myocardial tissue 12d region is selectively extracted. It should be noted that the low-pass filter 32 does not always selectively allow the myocardial tissue 12 d
It is not necessary to extract the Doppler signal of the area, and the high-pass filter commonly used in the conventional ultrasonic Doppler diagnostic apparatus may be simply removed.

The low-pass filter 32 is connected to an autocorrelation unit 34 for performing a known correlation operation on the extracted low frequency band Doppler signal to obtain an autocorrelation.

The autocorrelation unit 34 is connected to a speed calculation unit 36 for obtaining the movement speed v _d of the subject with respect to the probe 10 from the correlation signal obtained by the autocorrelation unit 34. the output side, the Doppler frame memory 38 for temporarily storing the resulting movement velocity v _d is connected.

The Doppler frame memory 38 includes:
The speed component calculation unit 62 of the speed correction unit 60 is connected.

The velocity component calculating unit 62, a motion velocity vector v _d of myocardial tissue to the probe 10 of the ultrasonic beam axis j shown in FIG. 1, the center-of-gravity velocity vector output from the centroid arithmetic processor 40 v _g Component (v
_g * cosα), and subtracts the resulting velocity component (v _d −v _g).
* Cos α). Here, alpha is the angle between the ultrasonic beam axis j and the center of gravity velocity vector v _g.

The coefficient calculating section 64 obtains an angle γ between a straight line connecting the center of gravity G and each point of the living tissue on the ultrasonic beam axis j and the ultrasonic beam axis j, and further calculates the angle γ based on the angle γ. This is a calculation unit for calculating the correction coefficient cosγ.

A relative speed calculator 66 is connected to the output sides of the speed component calculator 62 and the coefficient calculator 64. The relative speed calculator 66 calculates a biological tissue with respect to the center of gravity G based on a speed component obtained by subtracting the speed component of the ultrasonic beam axis of the center of gravity speed vector from the motion speed obtained by the speed calculator 36, and a correction coefficient. This is a calculation unit for calculating the relative movement speed v _r of. The obtained relative movement speed v _r is displayed as a two-dimensional relative movement speed distribution of the living tissue on the display unit 74 via the DSC 70 and the D / A conversion unit 72 connected to the relative speed calculation unit 66.

Next, a description will be given of a procedure for obtaining the relative movement speed of the living tissue with respect to the reference point (center of gravity) according to the embodiment of the present invention.

First, the probe 10 transmits an ultrasonic beam and receives its reflected echo. The received wave is output to the detection unit 24 via the amplification unit 22, and the detection unit 24 uses the tomographic image of the subject (so-called B
Mode image) information is extracted and output to the center-of-gravity calculation processing unit 40 via the A / D conversion unit 26.

[0045] In the center-of-gravity arithmetic processing unit 40, from the tomographic image information output, it calculates the center of gravity G and the center of gravity velocity vector v _g of the blood flow area 16 of FIG. This will be described with reference to FIG.

First, the area calculation unit 42 determines that a certain frame n
Small area ΔS of blood flow area at (n: integer)
i and the area S of the entire blood flow area are obtained.

Assuming that the probe 10 is at the origin 0 of the polar coordinates, the i-th (i: integer) -th ultrasonic beam transmitted from the probe 10 is a myocardial tissue 12 (anterior wall) close to the probe 10. R _{i, a} and r _{i, 0} , the myocardial tissue 12 (back wall) far from the probe
Intersect with ri _{, 1} and ri _{, p at} a total of four points.

The contour 14 is determined, for example, by counting peaks occurring at the boundary of the myocardial tissue with respect to tomographic image information (amplitude information) obtained from a received wave for the i-th ultrasonic beam. . That is, among the four peaks, the second peak position from the peak closest to the origin 0 is defined as r _{i, 0} , and the peak position immediately before the farthest peak is defined as r _{i, 1} .

An averaging process is performed on the tomographic image information obtained in advance, and a predetermined value is lower than the amplitude value (luminance value) due to the myocardial tissue 12 and higher than the amplitude value (luminance value) due to blood. This tomographic image information is binarized using the threshold value of. Further, if the contour 14 of the myocardial tissue 12 is determined based on the binarized tomographic image information, even if a missing or the like occurs in the tomographic image information due to noise, it is possible to interpolate the missing or the like. A more accurate contour 14 can be extracted.

The minute area ΔSi of the blood flow area between the adjacent i-th and (i + 1) -th ultrasonic beam lines
Is given by the following equation.

[0051]

[Number 1] ^{_{ΔSi = (r i, 1 2}} -r i, 0 2) Δθ / 2 ··········· (1) where, [Delta] [theta] is, i-th and (i + 1) th ultrasound This is the angle between the beam lines.

The area S of the blood flow area can be obtained by adding a small area ΔSi as shown in the following equation.

[0053]

S = ΣΔSi (2) Small area ΔSi and area S of the obtained blood flow area
Is output to the center-of-gravity calculator 44 in FIG. Center of gravity calculation unit 4
In step 4, the center of gravity Gi of the small area ΔSi region in frame n is calculated and calculated as the center of gravity position vector Rgi, and the center of gravity G of the area S of the entire blood flow area is calculated and calculated as the center of gravity position vector Rg.

Center-of-gravity position vector element R of minute area ΔSi
The components r _gi and θ _gi of g _i (r _gi , θ _gi ) are given by the following equations, respectively.

[0055]

Rg _i = {(ri _{, 1} ² + ri _{, 0} ² ) / 2} ^1/2 (3)

Θg _i = (θ _i + θ _{i + 1} ) / 2 (4) The centroid position vector Rg (r _G of the blood flow area in frame n) , Θ _G ) are given by the following equation and output to the coefficient calculator 64 and the center-of-gravity speed calculator 46 in FIG.

[0056]

Rg (n) = ΣRg _i ΔSi / S (5) The center-of-gravity calculation unit 44 also performs a frame on frame n + 1 which is the next frame of frame n. n, a center-of-gravity position vector Rg (n + 1) is obtained, and this is sequentially calculated by the coefficient calculating unit 6.
4 and output to the center-of-gravity speed calculator 46.

The center-of-gravity speed calculator 46 obtains the moving speed of the center of gravity of the blood flow area by calculating the difference between the center-of-gravity position vectors Rg of the respective frames as in the following equation, and sequentially outputs the obtained speed to the speed component calculator 62.

[0058]

[6] _{v g (n) = {Rg} (n + 1) -Rg (n)} / Δt ······ (6) As described above, the center of gravity G and the center-of-gravity velocity vector v _g is obtained, The obtained center of gravity G is output to the coefficient calculator 64,
The center-of-gravity velocity vector v _g is outputted to the velocity component calculating unit 62.

On the other hand, based on the received wave, the quadrature detector 30
Extracts a Doppler signal. Further, the myocardial tissue 1 shown in FIG.
The Doppler signal according to 2d is selectively extracted.

Next, the autocorrelation unit 34 detects the myocardial tissue 1
The autocorrelation processing is performed on the Doppler signal in the low frequency band according to 2d to output a correlation signal, and the speed calculation unit 35
Calculates the velocity of movement of the myocardial tissue relative to the probe 10 in the direction of the ultrasonic beam axis j from the correlation signal as the velocity of movement v _d , which is temporarily stored in the Doppler frame memory 38.

Next, the center of gravity speed v
_g is output, and the Doppler frame memory 38 outputs the motion velocity v _d of the myocardial tissue with respect to the probe 10 in the direction of the ultrasonic beam axis j shown in FIG.
2 obtains the components of the ultrasonic beam axis j of gravity velocity vector _{v g (v g * cosα)} , from the motion velocity vector v _d, subtracting the component of the ultrasonic beam axis j of the center-of-gravity velocity vector v _g. As a result, the velocity component (v _d −v _g * c
osα) is obtained and output to the relative speed calculation unit 66.

The coefficient calculating unit 64 obtains an angle γ between a straight line connecting the center of gravity G and each point of the myocardial tissue on the ultrasonic beam axis j and the ultrasonic beam axis j, and further calculates the angle γ based on the angle γ. The correction coefficient cosγ is obtained and output to the relative speed calculation unit 66.

The relative velocity calculating section 66 calculates the relative movement velocity v _r of the myocardial tissue 12d with respect to the center of gravity G based on the following equation.

[0064]

Equation 7] _{v r = (v d -v g} * cosα) / cosγ ·········· (7) above processing myocardial tissue on the ultrasound beam lines constituting one frame The center of gravity G obtained for each point
Relative velocity v _r of each point of myocardial tissue 12d with respect to
Display unit 74 via SC 70 and D / A conversion unit 72
5 is displayed as a two-dimensional relative movement velocity distribution 12r of the myocardial tissue as shown by the hatched portion in FIG.

In the display, in the color Doppler method, the determined relative movement speed of the myocardial tissue moving in a direction approaching the center of gravity G is displayed in a predetermined color (for example, red), and the myocardial tissue moving in a direction moving away from the center of gravity G is displayed. Is displayed in a color (for example, blue) different from the relative movement speed of the subject tissue moving in the approaching direction.

Therefore, during the systole of the heart, the myocardial tissue moves in the direction approaching the center of gravity G, regardless of the distance from the probe 10, so that the relative movement velocity distribution 12r of the myocardial tissue is displayed in the same color. Is done. Conversely, during the diastole of the heart, the myocardial tissue moves in a direction away from the center of gravity G, as shown in FIG. 5, so that the relative movement velocity distribution 12r of the myocardial tissue is displayed in the same color as that in the systole.

Therefore, when such a color display is performed, the movement time phase of the subject can be confirmed. Further, if the display luminance is changed in accordance with the magnitude of the relative movement speed, a more detailed movement state at each point of the living tissue can be measured and diagnosed. If necessary, the center of gravity G from the center-of-gravity calculation processing unit 40 may be combined with the relative motion speed distribution 12r and displayed on the display unit 74.

When the reference point of a region defined by the contour, for example, a closed region such as a heart chamber, is set as the center of gravity, the coincidence between the center of gravity and the movement reference point of the subject is high. Therefore, if the relative movement speed of the living tissue with respect to the center of gravity is obtained, the movement state unique to the living tissue can be diagnosed more accurately. It is sufficient that the reference point is the center point of the movement of the subject, and the same effect can be obtained even if the reference point is not necessarily the center of gravity.

Further, when the reference point of the closed area of the subject is set as the center of gravity, the center of gravity element in each small area area within the closed area is obtained, and the center of gravity element is added. The center of gravity of the entire area can be obtained. The velocity of the center of gravity can be easily given by calculating the amount of movement of the center of gravity in the closed region between each frame.

Accordingly, the information on the center of gravity can be automatically calculated and obtained. When the operator of the ultrasonic diagnostic apparatus obtains the relative speed of the subject tissue with respect to the reference point, particularly, the reference point is displayed on the display screen. There is no need to perform operations such as specifying. Therefore, the diagnosis can be performed in a short time, and the accurate relative speed information can be displayed because the relative speed information is displayed with little variation and high reliability.

In this embodiment, the center of gravity is determined based on tomographic image information (amplitude information) of the myocardial tissue. However, from the two-dimensional velocity distribution of the myocardial tissue and the two-dimensional velocity distribution of the blood, FIG. The outline of the blood flow area 16 in the myocardial tissue 12d may be determined. If the contour is determined, it is possible to determine the center of gravity G and the center of gravity velocity vector v _g of the blood flow area 16 in the same manner as described above.

In general, in an ultrasonic Doppler diagnostic apparatus, the movement speed of a region moving in a direction orthogonal to the ultrasonic beam axis cannot be obtained due to the nature of the Doppler effect as shown in FIG. However, for example, by performing a predetermined interpolation process such as transmitting and receiving an ultrasonic wave from another direction, it is also possible to display the motion velocity distribution of the living tissue without any loss as shown in FIG.

[0073]

As described above, according to the ultrasonic diagnostic apparatus of the present invention, the reference point in the predetermined area of the subject is obtained, and the moving speed of the reference point between each frame is detected. Next, based on the movement speed of the reference point, displaying the relative movement speed of each point of the subject tissue with respect to the reference point, that is, displaying the relative movement of each tissue of the subject with respect to the overall movement of the subject. did.

Accordingly, the motion information of the entire subject is removed, and the motion speed unique to each subject tissue can be detected. Even for a subject such as a heart which beats while being twisted in a three-dimensional structure as a whole. In addition, it is possible to accurately diagnose abnormal movement of living tissue due to myocardial infarction or the like.

The relative movement speed of each point of the tissue moving in the direction approaching the obtained reference point is displayed in a predetermined color, and the relative movement speed of each point of the tissue moving in the direction moving away from the reference point is expressed by: If the color is displayed in a color different from the relative movement speed of the subject tissue moving in the approaching direction, for example, when the subject is a heart, during the systole of the heart, regardless of the distance from the probe, the myocardial tissue is Move in the direction approaching the reference point, the entire myocardial region on the screen is displayed in the same color. Conversely, during the diastole of the heart, the myocardial tissue moves in a direction away from the reference point, and thus is displayed in the same color different from the systole.

Therefore, the movement time phase of the subject can be easily confirmed. If the display luminance is changed according to the magnitude of the relative movement speed, a more detailed movement state at each point of the subject tissue can be measured and diagnosed.

When the reference point of an area defined by the contour, for example, a closed area such as a heart chamber, is set as the center of gravity, the coincidence between the center of gravity and the reference point of movement of the subject is high. Therefore, if the relative movement speed of the living tissue with respect to the center of gravity is obtained, the movement state unique to the living tissue can be diagnosed more accurately.

Further, when the reference point of the closed area of the subject is set as the center of gravity, the center of gravity element in each small area area within the closed area is obtained, and the center of gravity element is added. The center of gravity of the entire area can be obtained. The velocity of the center of gravity can be easily given by calculating the amount of movement of the center of gravity in the closed region between each frame.

Accordingly, the information of the center of gravity can be automatically calculated and obtained. When the operator of the apparatus obtains the relative movement speed of the subject tissue with respect to the reference point,
In particular, there is no need to perform operations such as designating a reference point on the display screen. Therefore, diagnosis can be performed in a short time and accurate diagnosis can be performed because relative motion speed information with small variations and high reliability is displayed.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a method for determining a relative movement speed of a myocardial tissue with respect to a center of gravity according to an embodiment of the present invention.

FIG. 2 is a schematic block diagram of an ultrasonic Doppler diagnostic apparatus according to an embodiment of the present invention.

FIG. 3 is a schematic block diagram of a center-of-gravity calculation processing unit in FIG. 2;

FIG. 4 is a conceptual diagram illustrating a method for calculating a reference point of a predetermined region of a subject according to the embodiment of the present invention.

FIG. 5 is a diagram showing a display example of a relative movement velocity distribution of myocardial tissue with respect to the center of gravity according to the embodiment of the present invention.

FIG. 6 is a diagram showing a display example of a motion velocity distribution of myocardial tissue by a conventional ultrasonic Doppler diagnostic apparatus.

[Explanation of symbols]

 Reference Signs List 10 probe 12 myocardial tissue 12r relative motion velocity distribution 14 contour 16 blood flow area 40 center of gravity calculation processing unit 60 speed correction unit 62 speed component calculation unit 64 coefficient calculation unit 66 relative speed calculation unit

Claims (6)

(57) [Claims] 1. An ultrasonic diagnostic apparatus for transmitting and receiving an ultrasonic beam to and from an object and displaying an ultrasonic image based on the received wave, comprising: Speed calculating means for calculating a movement speed; detecting means for detecting a contour of the subject tissue for each frame; determining a reference point in an area defined by the contour; determining a moving speed of the reference point between frames; Reference point calculation processing means; speed correction means for obtaining a relative movement speed of each point of the subject tissue with respect to the reference point based on the moving speed of the reference point and the movement speed of each point of the subject tissue. An ultrasonic diagnostic apparatus comprising: a display unit configured to display a relative movement speed of each point of the subject tissue with respect to the reference point. 2. The ultrasonic diagnostic apparatus according to claim 1, wherein the display unit two-dimensionally displays a relative movement speed of each point of the subject tissue, and the display unit moves in a direction approaching the reference point. The relative movement speed of each point of the subject tissue is represented by a predetermined color, and the relative movement speed of each point of the subject tissue moving in a direction away from the reference point is the relative movement speed of the subject tissue moving in the approaching direction. An ultrasonic diagnostic apparatus characterized by being represented by a predetermined color different from the relative movement speed. 3. The ultrasonic diagnostic apparatus according to claim 2, wherein the display unit displays the magnitude of the relative movement speed by luminance or a different hue. 4. The ultrasonic diagnostic apparatus according to claim 1, wherein the reference point is a center of gravity of the region. 5. The ultrasonic diagnostic apparatus according to claim 1, wherein the velocity correction unit is configured to detect each point of the subject tissue in an ultrasonic beam axis direction. Velocity component calculating means for subtracting the moving speed component of the reference point from the moving speed to obtain a speed component of each point of the subject tissue; andthe ultrasonic beam axis, each of the reference point and the subject tissue. A coefficient calculating means for obtaining a correction coefficient for the velocity component based on an angle formed by a straight line connecting the point and a point; and a relative relation between each point of the subject tissue with respect to the reference point based on the velocity component and the correction coefficient. An ultrasonic diagnostic apparatus comprising: a relative speed calculating means for obtaining a motion speed. 6. The ultrasonic diagnostic apparatus according to claim 1, wherein the reference point calculation processing means includes a center of gravity for each of a plurality of minute area regions within a region defined by the contour of the tissue. A center-of-gravity calculating means for calculating an element and calculating a center of gravity in the area for each frame based on the center-of-gravity element; and obtaining a moving amount of the center of gravity in the area between each frame, and moving the center of gravity based on the moving amount. An ultrasonic diagnostic apparatus comprising: a center-of-gravity velocity calculating means for determining a velocity.