JPH0549640A - Ultrasonic diagnostic device - Google Patents

Abstract

PURPOSE:To inhibit a display of a fluid speed vector having a variance in its magnitude and direction, comparing with other fluid speed vector in a certain area of an image frame, with regard to the ultrasonic diagnostic device for calculating and displaying the fluid speed vector. CONSTITUTION:The device is constituted by providing a data converting mechanism 1 of a fluid speed vector for accessing to a memory part 5 for storing data of the fluid speed vector, detecting the data of the fluid speed vector having a variance, and replacing it with data for showing other vector.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus for displaying a fluid flow in a subject as a vector.

In recent years, imaging of the inside of a living body using ultrasonic waves has become popular in the field of medical diagnosis. Further, in order to understand the heart disease and hemodynamics in the carotid artery, the state of blood flowing in the organ, that is, blood flow is required as information for diagnosis. Therefore, an ultrasonic diagnostic apparatus that displays blood flow has been provided.

[0003]

2. Description of the Related Art A conventional ultrasonic diagnostic apparatus uses a color Doppler function to display blood flowing in an organ such as a heart in a subject in real time. This was convenient for understanding the hemodynamics in the organ. More recently, there has been an increasing demand for an ultrasonic diagnostic apparatus that detects blood flow and displays it as a vector. Then, in order to meet this demand, some methods have been proposed.

FIG. 7 is a diagram for explaining an ultrasonic diagnostic apparatus for calculating and displaying a fluid velocity vector. Figure 7
At the ultrasonic probe 50, the ultrasonic transmitter 53
The ultrasonic pulse is transmitted from. The ultrasonic probe 50 pressed against the body surface 51 projects an ultrasonic beam in a certain direction of the heart 52. Ultrasonic probe 50
Receives the reflection of the projected beam and transmits it to the ultrasonic receiver 54.

In the B mode, the reflection of the beam transmitted to the ultrasonic receiver 54 is detected by the detection circuit 55 and converted into a digital signal by the analog-digital converter,
Data representing a tomographic image by ultrasonic waves is stored in the memories 57 to 59.
Accumulated in. When this data is displayed on the screen, the muscles and the like are reflected in white because the beam is strongly reflected, and the places where there is body fluid are reflected in black because the beam is weakly reflected.

On the other hand, the blood flow information includes a blood flow analysis unit 60 for analyzing fluid information in the beam direction and a blood flow analysis unit 6 for analyzing fluid information in the beam orthogonal direction.
1 is processed and stored in the memory 63 via the vector calculator 62. The memory 63 has data that specifies the magnitude, direction, and display position of each fluid velocity vector. An example is shown in Table 1.

[Table 1]

In Table 1 above, information specifying five vectors from vector P to vector T is shown. The “position in the image frame” is where data indicating which position of the vector the pixel is displayed as the starting point is stored. The "fluid velocity vector (orthogonal coordinate)" and the "fluid velocity vector (polar coordinate)" are used to store data for uniquely defining the vector, and have the same coordinate system but different vectors. The numerical values in Table 1 are not strictly accurate due to the processing of fractions.

[0008]

Considering Table 1 above, it is considered that the vectors P to T indicate the movements of the fluids located at positions close to each other in the subject. But,
The vector P is considered to have different properties when compared with the other vectors Q to T. That is, it is considered that the fluid indicated by the vector P and the fluid indicated by the vectors Q to T are different from each other.

FIG. 8 is a diagram for explaining display of a conventional fluid velocity vector. In FIG. 8, an image of a portion where the heart 64 is present in the tomographic image displayed on the screen is shown, and the fluid velocity vector is shown only for an arbitrary partial region 65 in the heart 64. Of the five fluid velocity vectors, four are in the same direction, but the other one is in the opposite direction.

It is considered that the vector pointing in the opposite direction is a result of the system for processing the reflected wave of the ultrasonic wave erroneously picking up the movement of the myocardium. The other four vectors are considered to correctly indicate the blood flowing in the heart when the appearance of the display is observed. Conventionally, such an image is often displayed. In such a case, there is a problem that a person who makes a medical diagnosis has to distinguish between a vector indicating a muscle movement and a vector indicating a blood flow.

In view of the above-mentioned conventional problems, the present invention suppresses the detection of a vector having a variation in size and direction as compared with other vectors and presenting the vector to a diagnostician. It is an object of the present invention to provide an ultrasonic diagnostic apparatus that does.

[0012]

According to the invention, the above mentioned objects are achieved by the means defined in the claims.

That is, the invention of claim 1 is an ultrasonic diagnostic apparatus for calculating and displaying a fluid velocity vector,
The ultrasonic diagnostic apparatus is provided with a fluid velocity vector data conversion mechanism that transforms the magnitude or orientation of each fluid velocity vector and data representing the magnitude and orientation according to a predetermined algorithm.

According to a second aspect of the present invention, in the fluid velocity vector data conversion mechanism, with respect to the fluid velocity vector data existing in an arbitrary region on one ultrasonic image frame, the average of each component of the fluid velocity vector is obtained. A value or standard deviation, and a calculating means for obtaining an average value and a standard deviation, and each component of the fluid velocity vector is determined by the average value or the standard deviation obtained by the calculating means and a value obtained based on the average value and the standard deviation. Based on the determination means for checking whether or not it falls within the defined range, and the fluid velocity vector data that does not fall within the range based on the determination result of the determination means, each component of the data is the average value or standard deviation obtained by the calculation means. The ultrasonic diagnostic apparatus according to claim 1, further comprising a replacement unit that replaces data obtained based on the above.

According to a third aspect of the present invention, in the fluid velocity vector data conversion mechanism, with respect to the fluid velocity vector data existing on pixels at the same position on a plurality of ultrasonic image frames, each component of the fluid velocity vector. Of the mean value or standard deviation, and a calculating means for obtaining the mean value and the standard deviation, and each component of the fluid velocity vector, based on the mean value or the standard deviation obtained by the calculating means, and the mean value and the standard deviation. Judgment means for checking whether or not it falls within the range defined by the obtained value, and based on the judgment result of the judgment means, the data of the fluid velocity vector which does not fall within the range,
The ultrasonic diagnostic apparatus according to claim 1, further comprising replacement means for replacing each component with data obtained based on the average value or standard deviation obtained by the calculation means.

According to a fourth aspect of the present invention, in the fluid velocity vector data conversion mechanism, fluid velocity vector data existing in an arbitrary region on one ultrasonic image frame or on a plurality of ultrasonic image frames. For fluid velocity vector data existing on pixels at the same position in
A mean value or standard deviation of each component of the fluid velocity vector, and a calculating means for obtaining the mean value and standard deviation, and each component of the fluid velocity vector are obtained based on the mean value and standard deviation obtained by the calculating means. Based on the determination means for checking whether it falls within the range determined by the value and the determination result of the determination means, the fluid velocity vector data that does not fall within the range is converted into the fluid velocity vector data in which each component is zero. The ultrasonic diagnostic apparatus according to claim 1, further comprising replacement means for replacing, and post-processing means for processing the data of the fluid velocity vector in which each component is zero based on each data of the fluid velocity vector falling within the range. ..

[0017]

The following description is based on the case of data representing the magnitude and direction of a vector. FIG. 1 is a diagram illustrating the principle of the present invention. In FIG. 1, the vector calculator 6 generates fluid velocity vector data from the output information of the blood flow analysis unit, and stores this in the memory 3 of the memory unit 5. The contents of the memory 3 are processed by the fluid velocity vector data conversion mechanism 1, and the result is stored in the memory 4. The display unit 2 displays the fluid velocity vector on the screen based on the data stored in the memory 4.

In the fluid velocity vector data conversion mechanism 1 shown in FIG. 1, a function of detecting data indicating a vector having different properties from the data indicating a plurality of vectors, and a function of converting the detected data. Have. Therefore, the ultrasonic diagnostic apparatus according to the present invention does not display the erroneous vector indicating the movement of the muscle together with the vector indicating the blood flow, so that it is possible to eliminate the problem that may be confusing for the diagnostician.

[0019]

FIG. 2 is a diagram showing an embodiment of the present invention. In FIG. 2, the memory 9 stores data that specifies a fluid velocity vector. The control circuit 8 controls the scanning of the memory 9 to read the data of the fluid velocity vector and the control of each part. The calculation means 11 obtains the average value and standard deviation of each vector component from the read fluid velocity vector data. The determination means 12 determines whether each vector component correctly indicates blood flow. The replacement unit 13 replaces each component of the vector based on the determination result of the determination unit 12. The memory 10 stores the converted fluid velocity vector data.

In FIG. 2, first, the control circuit 8 has a memory 9
, The x component of the vector component xi and the y component y
The data of i are respectively input to the average value calculation circuits 14 and 1 of the next stage.
Control to send to No. 6. Average value calculation circuits 14 and 16
Calculates the average value of the transmitted vector component data. Next, the control circuit 8 controls again to send the data to the memory 9, and the component data of each vector is sent to the standard deviation calculating circuits 15 and 17. Standard deviation calculation circuit 1
In 5 and 17, the standard deviation is calculated using the above-mentioned average value and the input component data of each vector.

Next, the weighting circuits 19 and 25 of the next stage,
Using the multipliers 21 and 28 and the adders 18, 22, 24, and 27, the upper limit x + kxδx and the lower limit x−kxδx of the range for determining the x component of the vector component are output, respectively, and for determining the y component. The upper limit y + kyδy and the lower limit y-kyσy of the range are output. Next, the control circuit 8 again controls the memory 9 to send the data of the vector component. Subsequently, the determination means 12 compares each of the above upper and lower limits with each vector component data to determine whether the component of each vector is included in each range.

The comparison circuit 20 compares the x component of each vector with the upper limit of the range of the x component, and outputs a logic level High signal when the x component of each vector is less than or equal to the upper limit. In the comparison circuit 23, the x component of each vector and x
The lower limit of the component range is compared, and when the x component of each vector is equal to or higher than the lower limit, the logic level High
Output a signal. Similarly, in the comparison circuit 26, the y component of each vector is compared with the upper limit of the range of the y component, and when the y component of the vector component is less than or equal to the upper limit, a logical level High signal is output. Further, the comparison circuit 29 compares the y component of each vector with the lower limit of the range of the y component, and when the y component of the vector component is equal to or higher than the lower limit, outputs a logic level High signal.

In the logical product circuit 30 in the next stage, when all the outputs of the comparison circuits 20, 23, 26, 29 in the previous stage are High signals, the High signal is sent as a logic level signal. In other words, the comparison circuits 20, 23, 2
6 to 29, the range for determining each component is determined by the average value of each of the x component and y component of each vector and the weighted standard deviation, and the component of each vector is x. If both the component and the y component are within the range, a high signal is sent from the AND circuit 30.

Next, in the selection circuits 31 and 32, when the output of the AND circuit 30 in the preceding stage is the High signal,
The vector component data from the memory 9 is passed and l
When the signal is an ow signal, the average value “outside 1”,
Pass each "outer 2". Therefore, if the determined component of each vector is outside the determination range for both the x component and the y component, the x component is replaced with the average value of the x component, and the y component is the y component of the y component. The average value is replaced and written in the memory 10, and if it is within the range of determination, the values of the x component and y component of each vector as they are are written in the memory 10.

[Outer 1]

[Outside 2]

FIG. 3 is a diagram showing a scanning method of the memory by the control circuit shown in FIG. FIG. 3A shows a memory scanning method by the control circuit according to the second aspect. FIG. 3B shows a method of scanning the memory by the control circuit according to the third aspect. In FIG. 3A, a partial area 34 on one image frame 33 is scanned. Therefore, the data of the fluid velocity vector in this partial area is read out. In FIG. 3B, since the pixel at a certain same position on the plurality of image frames 35 to 37 is scanned, the fluid velocity vector data on this pixel is read.

FIG. 4 is a diagram for explaining the invention of claim 2.
It In FIG. 4, the control circuit is a partial area shown in FIG.
Scan the region 66 and find the five fluid velocity vectors in it
V_p, V_q, V_r, V_s, V_tRead the data of. Be
Cutle V_pIs another vector V _q, V_r, V_s, V_tWhat is
Facing different directions. Therefore, the vector V_pIs blood
Considered to indicate muscle movement, etc., rather than indicating current
available.

The calculating means of the invention of claim 2 obtains the average value and the standard deviation. Now, it is assumed that there are n vectors in an arbitrary area. These n vectors are V ₁ , V
₂ , V ₃ , ..., V _n , and the x component of each vector is x
₁ , x ₂ , x ₃ , ..., X _n , the y component is y ₁ , y ₂ , y
₃ , ..., Y _n . The average value “outer 1” of the x component at this time can be calculated by “Equation 1”.

[Equation 1] The standard deviation σx of the x component can be calculated by “Equation 2”.

[Equation 2]

Next, the average value and standard deviation of the y component can be calculated in the same manner as the x component. The average value “outer 2” of the y component can be expressed by “Equation 3”.

[Equation 3] The standard deviation σy of the y component can be calculated by “Equation 4”.

[Equation 4] The range of the x component is determined as follows using the average value “outer 1” obtained by “Equation 1” and the standard deviation σx obtained by “Equation 2”. Range of x component = [outer 1−kxσx, outer 1 + kxσx] Similarly, the range of the y component is determined as follows. Range of y component = [outer 2-kyσy, outer 2 + kyσy] Note that kx and ky are values obtained by experiments.

FIG. 4B shows the range of the x component and the range of the y component for the vectors V _p , V _q , V _r , V _s , and V _t shown in FIG. 4A. The determination means of the invention of claim 2 is the x of each vector V _p , V _q , V _r , V _s , and V _t .
Determine if the component and y component fall within the x component range and the y component range. In FIG. 4B, the vector V _p is
It turns out that it is out of range.

FIG. 4C shows the result of replacing the vector V _p with the vector V _PP by the replacing means of the invention of claim 2. Other vectors V _q , V _r ,
V _s and V _t remain unchanged. Therefore, the vectors displayed on the ultrasonic diagnostic apparatus are the vectors V _pp , V _q , V _r ,
It becomes V _s and V _t .

FIG. 5 is a diagram for explaining the invention of claim 3.
It FIG. 5 shows three ultrasonic image frames 67-69 as a pair.
An example of an elephant is shown. Each ultrasonic image frame 67-
Each vector existing on the same pixel on 69
The vector on the ultrasonic image frame 67 is V_l, Ultrasonic
V on the image frame 68_m, Ultrasound image frame
V on vector 69_nAnd Also, the vector V
_lThe component of (x_l, Y _l), The vector V_mIngredient of
To (x_m, Y_m), The vector V_nThe ingredients of
(X_n, Y_n). At this time, if n = 3, the "number
1 "is used to find the average value" outer 1 "of the x component, and" equation 2 "
Is used to obtain the standard deviation σx of the x component. Similarly,
Using "Equation 3", the average value "outside 2" of the y component is calculated, and
Further, the standard deviation σy of the y component is obtained by using “Equation 4”.

Next, the range of the x component is determined as follows using the average value “outer 1” of the x component and the standard deviation σx. Range of x component = [outer 1−s _X σ _x , outer 1 + s _x σ _x ] Here, s _X is a value obtained by experiment. Further, using the average value “outer 2” of the y component and the standard deviation σy,
The range of the y component is defined as follows. Range of y component = [outer 2-s _y σ _y , outer 2 + s _y σ _y ] (8) Here, s _y is a value obtained by an experiment.

Next, it is determined whether the x component of each vector is within the x component range, and whether the y component of each vector is within the y component range. The principle will be specifically described with reference to FIG. “Outer 1” in FIG. 5B indicates vectors V ₁ to V 1.
The average value of x components up to _n , and “outer 2” is the average value of y components from vectors V ₁ to V _n . Further, sxσx in the figure is a value obtained based on the standard deviation of the x component from the vectors V _l to V _n , and syσy is based on the standard deviation of the y component from the vectors V _l to V _n. It is the value obtained by

In the figure, the range of the x component and the range of the y component are shown using x, sxσx, y, syσy.
From the figure, it can be seen that the x component of the vector V _l does not fall within the x component range from the vector V _l to the vector V _n . In the invention of claim 3, if each x component of the vector is within the range of the x component and each y component is not within the range of the y component, the x component and the y component of the vector are averaged. Since a means for substituting the value “outer 1” and the average value “outer 2” is adopted, the components (x _l , y _l ) of the vector V _l in FIG. Replaced by the value "outside 2". This is shown in FIG. 5 (c). Vector V _ll in the figure, by the substitution means the components of the vector _{V l (x l, y l} ),
Each is replaced with an average value, and the components of the vector V _l are (outer 1, outer 2). It should be noted that in the above detailed description, the case of converting into the “average value” itself was taken as an example, but the data may be converted into data obtained based on the average value or standard deviation. Further, it goes without saying that the same data conversion can be performed in the case of only the size or only the direction.

By adopting the above means, a plurality of fluid velocity vectors existing on the same pixel on a plurality of ultrasonic image frames have a vector having a direction and a magnitude different from those of other fluid velocity vectors. When this is done, it can be displayed in the same direction and size as other vectors. The invention of claim 3 is almost the same as the basic configuration of the invention of claim 2, but the difference is that the memory access method of the control circuit and the value of the stage that outputs the coefficients of the standard deviations σx and σy are different. It is a point. With regard to the memory access method, it can be understood by those skilled in the art that if the data relating to all the vectors to be displayed in advance is stored in the memory, both inventions can be implemented with the basic configuration shown in FIG. 2 only by changing the access method. Easy to understand.

FIG. 6 is a diagram showing an embodiment of the invention of claim 4. Although the calculation means and the determination means are not shown in FIG. 6, it is assumed that they have the same configuration as that shown in FIG. The replacing means 38 of FIG. 6 and the replacing means 13 of FIG. 2 differ in the value when replacing the vector in the range of each component. That is, in FIG. 6, when the AND circuit 40 is turned on and it is recognized that the vector indicates the movement of the muscle, each component of this vector is replaced with the value “0” by the selection circuits 39 and 41. Be done.

The data stored in the memory 42 is the vector indicating the blood flow and the zero vector. Therefore, by displaying this content, it is possible to suppress only the display of the vector indicating the movement of the muscle. Further, the data in the memory 42 can be further converted by the post-processing means 70. The post-processing means 70 includes, in the determination means, average value calculation circuits 43 and 46 for obtaining the average value of each component of the vector within the range, and a comparison circuit 44 for determining whether the vector read from the memory 42 is a zero vector. 47 and selection circuits 45 and 48 for replacing each component of the zero vector.

After all, the post-processing means 70 converts the zero vector data out of the vector data stored in the memory 42 and outputs the other data as it is. The data of the zero vector is replaced by the data indicating the average value of the vectors within the range in the determination means.
The output data of the post-processing means 70 is stored in the memory 49,
This content is displayed.

In the present embodiment, each component of the vector is shown using Cartesian coordinates. However, this Cartesian coordinate indicates a Cartesian coordinate in a broad sense, and is quoted from the "Mathematical Dictionary" edited by the Mathematical Society of Japan. That is, the orthogonal coordinate system in this specification naturally includes a polar coordinate system in addition to the xy Cartesian coordinate system.

[0040]

As described above, according to the present invention,
It is possible to superimpose a plurality of vectors on different positions of the blood flow image and display them without variation when they are displayed. Therefore, the present invention greatly contributes to the performance improvement of the ultrasonic diagnostic apparatus.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a diagram showing an example of the present invention.

FIG. 3 is a diagram showing a method of scanning a memory by a control circuit.

FIG. 4 is a diagram for explaining the invention of claim 2;

FIG. 5 is a diagram for explaining the invention of claim 3;

FIG. 6 is a diagram showing an embodiment of the invention of claim 4;

FIG. 7 is a diagram illustrating an ultrasonic diagnostic apparatus that calculates and displays a fluid velocity vector.

FIG. 8 is a diagram illustrating display of a conventional fluid velocity vector.

[Explanation of symbols]

1 Fluid velocity vector data conversion mechanism 2 Display unit 3, 4, 9, 10, 42, 49, 57 to 59, 63
Memory 5 Memory unit 6,62 Vector calculator 8 Control circuit 11 Calculation means 12 Judgment means 13,38 Substitution means 14, 16, 43, 46 Average value calculation circuit 15, 17 Standard deviation calculation circuit 18, 22, 24, 27 Addition Unit 19,25 Weighting circuit 20,23,26,29,44,47 Comparison circuit 21,28 Multiplier 30,40 AND circuit 31,32,39,41,45,48 Selection circuit 33,35-37, 67 to 69 Image frame 34, 65, 66 Partial region 50 Ultrasonic probe 51 Body surface 52, 64 Heart 53 Ultrasonic transmitter 54 Ultrasonic receiver 55 Detection circuit 56 Analog-digital converter 60, 61 Blood flow analysis unit 70 Post-processing means

Claims (4)

[Claims] 1. An ultrasonic diagnostic apparatus for calculating and displaying a fluid velocity vector, wherein the magnitude or orientation of each fluid velocity vector and the fluid velocity vector for converting data representing the magnitude and orientation according to a predetermined algorithm. An ultrasonic diagnostic apparatus comprising the data conversion mechanism described above. 2. A fluid velocity vector data conversion mechanism, for fluid velocity vector data existing in an arbitrary region on one ultrasonic image frame, an average value or standard deviation of each component of the fluid velocity vector, And a calculating means for obtaining an average value and a standard deviation, and each component of the fluid velocity vector is within a range determined by the average value or standard deviation obtained by the calculating means, and a value obtained based on the average value and the standard deviation. Based on the determination means for checking whether or not it enters, based on the determination result of the determination means, the data of the fluid velocity vector that does not fall within the range is determined based on the average value or standard deviation of each component obtained by the calculation means. The ultrasonic diagnostic apparatus according to claim 1, further comprising: a replacement unit that replaces the obtained data. 3. A fluid velocity vector data conversion mechanism, for fluid velocity vector data existing on pixels at the same position on a plurality of ultrasonic image frames, an average value or a standard value of each component of the fluid velocity vector. Deviation, and calculation means for obtaining the average value and standard deviation, and each component of the fluid velocity vector is determined by the average value or standard deviation obtained by the calculation means, and the value obtained based on the average value and standard deviation Based on the judgment result of the judgment means for judging whether or not it falls within the range, the data of the fluid velocity vector which does not fall within the range is converted into the average value or the standard deviation obtained by the calculation means based on the judgment result of the judgment means. The ultrasonic diagnostic apparatus according to claim 1, further comprising: a replacement unit that replaces the data obtained based on the data. 4. A fluid velocity vector data converting mechanism, wherein fluid velocity vector data existing in an arbitrary region on one ultrasonic image frame or at the same position on a plurality of ultrasonic image frames. With respect to the data of the fluid velocity vector existing on the pixel, an average value or standard deviation of each component of the fluid velocity vector, and a calculating means for obtaining the average value and the standard deviation, and each component of the fluid velocity vector, Based on the determined average value or standard deviation and the value obtained based on the average value and standard deviation, a determining means for determining whether or not it falls within the range based on the determination result of the determining means Replacement means for replacing the fluid velocity vector data with fluid velocity vector data for which each component is zero, and the fluid velocity for which each component is zero The ultrasonic diagnostic apparatus according to claim 1, wherein the data of the vector provided and a post-processing means for processing based on the data of the fluid velocity vector falls within the above range.