JP5999997B2 - Ultrasonic diagnostic equipment - Google Patents

Description

  The present invention relates to an ultrasonic diagnostic apparatus that measures a state of a subject such as internal tissue and blood flow.

  In order to measure the state inside the human body, there is known an ultrasonic diagnostic apparatus that transmits ultrasonic waves into the human body, receives reflected ultrasonic waves, and displays an image of the form inside the human body. In the ultrasonic diagnostic apparatus, the state of blood flow or the like is displayed in color on an image using the Doppler effect of ultrasonic waves.

  For example, when an ultrasonic wave hits a blood cell moving in a blood vessel or the like, the frequency of the reflected ultrasonic wave is shifted by the Doppler effect, and thus the state of the blood flow is measured by obtaining the shift amount. However, the moving speed (not 0) is also detected in portions other than the blood flow due to the movement of the living tissue and the movement of the probe itself. In order to accurately obtain the blood flow state, it is necessary to remove a high level echo signal called a clutter component reflected by a living tissue or the like. An MTI filter (Moving Target Indicator Filter) is known as a means for removing clutter components. The MTI filter has a high-pass filter configuration. The reflected signal (clutter component) from living tissue that is stationary or moving at low speed in the subject is at a high level, but the Doppler shift frequency is low. Therefore, if the signal after detection is passed through the MTI filter, it is strongly attenuated. The

  FIG. 1 is a schematic configuration diagram of an ultrasonic diagnostic apparatus conventionally used for displaying blood flow in color.

  An ultrasonic diagnostic apparatus 80 shown in FIG. 1 includes an ultrasonic probe 81, a transmission circuit 82, a reception circuit 83, a tomographic image processing unit 84, a color Doppler processing unit 85, a DSC 86, and a display device 87. The ultrasonic probe 81 is a probe in which a plurality of transducers (not shown) are arranged. The transmission circuit 82 outputs ultrasonic pulses by transmitting pulse waves to a plurality of transducers included in the ultrasonic probe 81. The reflected ultrasonic wave reflected inside the human body is received by a transducer (not shown) and converted into an electric signal, and is received by the receiving circuit 83 to become a received signal.

  The tomographic image processing unit 84 obtains tomographic information by processing the received signal. More specifically, the tomographic image processing unit 84 determines whether the reflection object is in the form of a reflector based on the time from transmitting an ultrasonic pulse to receiving a reflected ultrasonic wave and the amplitude of the obtained electrical signal. By calculating the information, tomographic image information (B mode information) of the human body tissue is obtained.

  The received signal is also supplied to the color Doppler processing unit 85. The color Doppler processing unit 85 includes an orthogonal detection unit 851, an MTI filter 852, a correlation calculation unit 853, and a data selection unit 854. The quadrature detection unit 851 performs quadrature detection by multiplying the received signal by reference signals (sine wave and cosine wave) whose phases are shifted from each other by 90 degrees. By quadrature detection, two systems of signals consisting of a real part I (in-phase) and an imaginary part Q (quadra) are generated. The two systems of received signals composed of the real part I and the imaginary part Q include a clutter component reflected by a moving body such as an organ wall or a valve and a blood flow component reflected by the blood flow. The MTI filter 852 extracts a blood flow component by a filtering process that attenuates the clutter component. The correlation calculation unit 853 calculates a blood flow velocity for each point in the human body by performing a correlation calculation on the output signal of the MTI filter 852 using a correlation function. In correlation calculation unit 853, the dispersion value of the speed obtained by transmitting the pulse wave a plurality of times and the power representing the blood flow rate are also obtained.

  The data selection unit 854 selects and outputs the data selected according to the operation of the operator among the velocity, the variance value, and the power, which are indices representing the blood flow obtained by the correlation calculation unit 853. Here, when the power is smaller than the predetermined threshold, the data selection unit 854 replaces the output index with “0”, that is, an index indicating that there is no blood flow, and outputs the result.

  The reception signal obtained from the reception circuit 83 includes both the clutter component and the blood flow component, but the clutter component is attenuated by the MTI filter 852. Therefore, a portion where the power obtained from the signal after passing through the MTI filter 852 is large is determined to be blood flow, and a portion where the power is low is determined to have a clutter component remaining. By replacing the index with “0” in accordance with this determination, the display of clutter components that could not be removed can be suppressed to a certain degree.

  The DSC 86 of the ultrasonic diagnostic apparatus 80 is a digital scan converter, and is a circuit that converts tomographic image information into a scanning signal format that can be displayed on the image display apparatus. Data obtained by the tomographic image processing unit 84 and the color Doppler processing unit 85 is converted into a bitmap format that allows image display by the DSC 86 and supplied to the display device 87 as an image signal. Here, the index representing the blood flow by the color Doppler processing unit 85 is displayed in color. The display device 87 is a color image display device, and displays an image in which color information representing blood flow is superimposed on a tomographic image of human tissue.

  In display by color Doppler, it is desired to suppress the display of clutter, which is noise, in an image. However, for example, if the clutter component is further removed by changing the threshold value that is a condition for replacing the index in the data selection unit 854, the blood flow is displayed as having no blood flow up to a remarkable blood flow portion. The trend will increase.

  Here, Patent Document 1 discloses an apparatus that removes clutter components using an adaptive filter. Patent Document 2 discloses an apparatus that attempts to match a filter cutoff characteristic to a clutter component by dynamically converting (shifting) the frequency axis in filter processing based on a signal dispersion value. ing.

US Pat. No. 5,349,524 Japanese Patent Laid-Open No. 2004-73672

  However, since the apparatus disclosed in Patent Document 1 has a large adaptive filter, even if it can be applied to a high-function apparatus, it cannot be applied to a popular apparatus. The apparatus of Patent Document 2 cannot be applied to a widespread apparatus because the scale of a circuit for calculating a coefficient for wave number axis shift is large. Further, even if the frequency axis is shifted, the cutoff characteristic of the filter is limited by the coefficient of the filter, and it cannot be said that the removal of the clutter component is sufficient.

  Here, it is conceivable that power is obtained based on a signal before processing by the MTI filter, and the data selection unit performs index replacement in consideration of the obtained power.

  FIG. 2 is a schematic configuration diagram illustrating a color Doppler processing unit of the diagnostic apparatus in consideration of the power of the signal before processing by the MTI filter.

  The diagnostic device shown in FIG. 2 differs from the diagnostic device shown in FIG. 1 in that the data selection unit 954 in the color Doppler processing unit 95 and the power calculation unit 955 are provided, and the remaining points are the diagnostics shown in FIG. Same as the device. The power calculation unit 955 calculates the power Pp based on the signal before processing by the MTI filter 952. Unlike the power P obtained by the correlation calculation unit 953, this power Pp represents the power before processing by the MTI filter 952, and therefore the clutter component is dominant.

  FIG. 3 is a block diagram for explaining the operation of the data selection unit in the color Doppler processing unit shown in FIG.

  The data selection unit 954 replaces the same as the data selection unit 854 shown in FIG. 1, that is, when the power P is smaller than the predetermined threshold Pth, the output index out is set to “0”, that is, there is no blood flow. Replace with the index to represent. In addition to this, when the power Pp obtained by the power calculation unit 955 is larger than the threshold value Ppth1, the data selection unit 954 considers it as a clutter component, and sets the output index out to “0”. Also, if the velocity V obtained by the correlation calculation unit 953 is slower than the threshold value Vth1, it is regarded as a clutter component that could not be removed by the MTI filter 952, and is replaced with “0”. In this selection process, the property that the blood flow is faster than the movement of the body tissue is used for the velocity V.

  In the diagnostic apparatus shown in FIGS. 2 and 3, since the power and speed V before processing by the MTI filter 952 are taken into account, the clutter component is easily discriminated as compared with the diagnostic apparatus shown in FIG. However, in an ultrasonic diagnostic apparatus, it is desired to further suppress noise due to clutter components.

  An object of the present invention is to solve the above-mentioned problems, and to provide an ultrasonic diagnostic apparatus in which noise due to clutter components is suppressed and blood flow is displayed more clearly.

The ultrasonic diagnostic apparatus of the present invention that achieves the above object repeats the transmission of an ultrasonic pulse into the subject and the reception of the reflected ultrasonic wave reflected back within the subject a plurality of times. An ultrasonic diagnostic apparatus for displaying blood flow at each point in an ultrasonic transmission / reception area in a subject based on a received signal obtained during
An MTI filter that attenuates the clutter component in the received signal including both the clutter component and the blood flow component by attenuating the low frequency component in the received signal;
A pre-attenuation correlation calculation unit for obtaining a dispersion value and power of velocity at each point from a reception signal before attenuation of the clutter component in the MTI filter;
A post-attenuation correlation calculation unit for obtaining a blood flow velocity at each point from the signal after attenuation by the MTI filter;
An image display unit for displaying an image representing blood flow at each of the points;
Among the above points, the dispersion value obtained by the pre-attenuation correlation calculation unit matches a dispersion condition in which the dispersion value is lower than a first threshold, and the movement speed obtained by the post-attenuation correlation calculation unit is a second value. When the blood flow non-display condition is that at least one of the speed condition below the threshold value and the power condition obtained by the pre-attenuation correlation calculation unit exceeds the third threshold value is satisfied. For the points that meet the blood flow non-display condition including, the index obtained by the post-attenuation correlation calculation unit is replaced with an index indicating that there is no blood flow, and the blood is displayed on the image display unit based on this index. And a display control unit for displaying an image representing a flow.

From the received signal before attenuation of the clutter component in the MTI filter, the dispersion value of the velocity at each of the above points is obtained, and there is no blood flow after considering the case where this dispersion value is below the first threshold value. Consider replacing it with an index that represents. If the variance value of the velocity in the signal before the MTI filter processing is large, it can be said that it represents a variation in the moving velocity of each blood cell in the bloodstream. Conversely, if the variance value is small, it may be a clutter of an organ or the like. High nature. By taking into account individual differences in the moving speed of each blood cell, it is possible to suppress noise due to clutter components by discriminating whether or not it is a clutter. As a result, blood flow is displayed more clearly.

However, if the variance value due to the signal before attenuation by the MTI filter is small, there is a high possibility that the clutter is an organ or the like, but the variance value may be small even for blood flow. Therefore, in the ultrasonic diagnostic apparatus of the present invention , a point that matches both the speed condition for the moving speed and the power condition for the power and the dispersion condition is replaced with an index indicating that there is no blood flow. . This suppresses erroneous detection in which a portion that is originally blood flow is regarded as having no blood flow. As a result, the blood flow is clearly displayed.

  In the ultrasonic diagnostic apparatus of the present invention, the blood flow non-display condition is that the display control unit satisfies all of the speed condition, the power condition, and the dispersion condition. For the point that matches the non-display condition, the index obtained by the post-attenuation correlation calculation unit is replaced with an index indicating that there is no blood flow, and an image representing blood flow on the image display unit based on this index Is preferably displayed.

  By replacing points that meet all of the speed condition, power condition, and dispersion condition with an index indicating that there is no blood flow, erroneous detection of a portion that is inherently blood flow can be further suppressed. As a result, the blood flow is displayed more clearly.

  In the post-attenuation correlation calculation unit, the point that matches the condition based on the blood flow index obtained from the signal attenuated by the MTI filter is replaced with an index indicating that there is no blood flow, so that the blood flow is inherently blood flow. The false detection of the part is further suppressed. As a result, the blood flow is displayed more clearly.

  In the ultrasonic diagnostic apparatus of the present invention, the display control unit includes a second power condition in which the power obtained by the pre-attenuation correlation calculation unit exceeds a fourth threshold value that is larger than the third threshold value, The second velocity condition in which the blood flow velocity obtained by the post-attenuation correlation calculation unit falls below a fifth threshold smaller than the second threshold, and the power obtained by the post-attenuation correlation calculation unit falls below the sixth threshold. Matching any one of at least one condition selected from among the third power conditions is the second blood flow non-display condition, and the point that matches the second blood flow non-display condition It is preferable that the index is replaced with an index indicating that there is no blood flow, and an image indicating blood flow is displayed on the image display unit based on the index.

  The second power condition for the power obtained by the correlation calculation unit before attenuation, the second velocity condition for the blood flow velocity obtained by the correlation calculation unit after attenuation, and the third condition for the power obtained by the correlation calculation unit after attenuation By replacing the point that matches any one of the power conditions with an index indicating that there is no blood flow, noise due to the clutter component can be further suppressed. As a result, the blood flow is displayed more clearly.

  As described above, according to the present invention, an ultrasonic diagnostic apparatus that suppresses noise due to clutter components and displays blood flow more clearly is realized.

It is a schematic block diagram of the conventional ultrasonic diagnostic apparatus. It is a schematic block diagram which shows the color Doppler process part of the diagnostic apparatus which considered the power of the signal before the process by a MTI filter. It is a block diagram explaining operation | movement of the data selection part in the color Doppler process part shown in FIG. 1 is a schematic configuration diagram of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. It is a block diagram explaining operation | movement of the data selection part which concerns on this embodiment. It is a figure which shows the example of a display of the image by an ultrasonic diagnosing device.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 4 is a schematic configuration diagram of an ultrasonic diagnostic apparatus according to an embodiment of the present invention.

  The ultrasound diagnostic apparatus 10 illustrated in FIG. 4 includes an ultrasound probe 11, a transmission circuit 12, a reception circuit 13, a tomographic image processing unit 14, a color Doppler processing unit 15, a DSC 16, and a display device 17. Here, the DSC 16 and the display device 17 correspond to an example of an image display unit according to the present invention.

  The ultrasonic probe 11, transmission circuit 12, reception circuit 13, tomographic image processing unit 14, DSC 16, and display device 17 shown in FIG. 4 are the same as the ultrasonic probe 81 and transmission circuit described with reference to FIG. 82, the receiving circuit 83, the tomographic image processing unit 84, the DSC 86, and the display device 87 have the same configuration and function. Therefore, the description of the ultrasonic diagnostic apparatus 10 of the present embodiment that overlaps with the ultrasonic diagnostic apparatus 80 of FIG. 1 is omitted, and the color Doppler processing unit 15 that is different from the ultrasonic diagnostic apparatus 80 of FIG.

  The color Doppler processing unit 15 of the ultrasonic diagnostic apparatus 10 illustrated in FIG. 4 includes an orthogonal detection unit 151, an MTI filter 152, a post-attenuation correlation calculation unit 153, a data selection unit 154, and a pre-attenuation correlation calculation unit 156. Here, the data selection unit 154 corresponds to an example of a display control unit according to the present invention.

  The quadrature detection unit 151 performs quadrature detection by multiplying the reception signal supplied from the reception circuit 13 by reference signals (sine wave and cosine wave) whose phases are shifted from each other by 90 degrees. By quadrature detection, two systems of signals consisting of a real part I (in-phase) and an imaginary part Q (quadra) are generated. The received signal composed of the real part I and the imaginary part Q includes a clutter component reflected by a moving body such as an organ wall or a valve and a blood flow component reflected by the blood flow. The orthogonally detected reception signals I and Q are supplied to the MTI filter 152 and the pre-attenuation correlation calculation unit 156.

  The MTI filter 152 extracts a blood flow component by a filtering process that attenuates the clutter component. The MTI filter 152 is a high-pass filter and attenuates clutter components by attenuating low-frequency components. The MTI filter 152 of the present embodiment employs a secondary to quaternary tap configuration, thereby realizing a scale that can be implemented by the popular ultrasonic diagnostic apparatus 10 and a processing capability suitable for the amount of received signals. ing.

  The received signal whose clutter component has been attenuated by the MTI filter 152 is supplied to the post-attenuation correlation calculation unit 153. The post-attenuation correlation calculation unit 153 calculates a blood flow velocity V for each point in the human body by performing a correlation calculation on the output signal of the MTI filter 152 using a correlation function. A plurality of velocities V are obtained in response to the transmission of the pulse wave a plurality of times. Here, the average value of the velocities obtained as a representative value is the velocity V. In addition, the post-attenuation correlation calculation unit 153 also calculates the velocity dispersion value T obtained by transmitting the pulse wave a plurality of times and the power P representing the blood flow.

  The pre-attenuation correlation calculation unit 156 calculates a velocity dispersion value Tp at each point in the human body by performing a correlation operation on the received signal before attenuation of the clutter component by the MTI filter 152 using a correlation function. . Further, the pre-attenuation correlation calculation unit 156 also obtains the power Pp at each point from the received signal before the attenuation of the clutter component. Hereinafter, the dispersion value Tp obtained based on the reception signal before attenuation of the clutter component is referred to as a dispersion value Tp before attenuation, and the power Pp obtained based on the reception signal before attenuation of the clutter component is the power Pp before attenuation. Called. Further, a lowercase letter “p” is added as a suffix to the sign of each data obtained based on the received signal before attenuation of the clutter component.

  The pre-attenuation dispersion value Tp calculated by the pre-attenuation correlation calculation unit 156 includes the dispersion of the velocity component due to the clutter and the dispersion of the velocity component due to the blood flow at each point. Here, since the velocity component of the blood flow reflects the reflection signal of the blood cells in the blood, the velocity dispersion value is relatively large due to variations in the moving speed of each blood cell. On the other hand, since the velocity component of the clutter is caused by the integral movement of the organ or the like, the variance value of the velocity is relatively small.

  The data selection unit 154 sends the index obtained by the post-attenuation correlation calculation unit 153, that is, the index selected according to the operator's instruction from the speed V, the variance value T, or the power P to the DSC unit 16. Then, an image is displayed on the display device 17 based on the index. For example, when the speed V is selected, the speed V obtained by the post-attenuation correlation calculation unit 153 is sent to the DSC unit 16.

[Blood flow non-display condition]
However, the data selection unit 154 according to the present embodiment indicates that there is no blood flow as an index obtained by the post-attenuation correlation calculation unit 153 for each point that matches a predetermined blood flow non-display condition. Replace with an indicator. In this embodiment, the index indicating that there is no blood flow is “0”.

  FIG. 5 is a configuration diagram illustrating the operation of the data selection unit according to the present embodiment. FIG. 5 shows conditional expressions in the data selection unit 154 of the color Doppler processing unit 15. In FIG. 5, an arrow extending to the left side of the data selection unit 154 indicates an index to be selected as an output, and arrows extending above and below the data selection unit 154 indicate values determined as conditions.

  The blood flow non-display condition in the data selection unit 154 includes a condition where the pre-attenuation dispersion value Tp is lower than the first threshold value Tpth as the dispersion condition “Tp <Tpth”. As one condition that the pre-attenuation dispersion value Tp falls below the first threshold value Tpth, the output index out is replaced with “0”.

  Since the pre-attenuation dispersion value Tp is based on the received signal before the clutter component is attenuated by the MTI filter 152, the dispersion of the velocity component due to the clutter and the dispersion of the velocity component due to the blood flow are included. A large pre-attenuation dispersion value Tp represents a variation in the moving speed of each blood cell, and a small pre-attenuation dispersion value Tp has a high probability of representing clutter due to an integral movement of an organ or the like. The data selection unit 154 replaces the output index out with “0” on the condition that the pre-attenuation dispersion value Tp falls below the first threshold value Tpth, so that noise due to clutter is displayed on the image. Can be suppressed. As a result, the blood flow is clearly displayed in the image. In addition, since the pre-attenuation dispersion value Tp is used as a replacement condition for the index out, it can be realized with a low-load process as compared with the case where it is used as a filter coefficient calculation condition, for example.

  Further, the blood flow non-display condition in the data selection unit 154 includes a condition where the speed V is lower than the second threshold value Vth2 as the speed condition “V <Vth2”. The blood flow non-display condition includes a condition where the power Pp before attenuation exceeds the third threshold value Ppth2 as the power condition “Pp> Ppth2”. A small pre-attenuation dispersion value Tp is likely to represent clutter, but even in the case of blood flow, the pre-attenuation dispersion value Tp may be small. Therefore, by replacing the output index “out” with “0” for a point that matches both the dispersion condition and the power condition, and the dispersion condition, the blood flow portion is Misdetection that is considered to be absent is suppressed.

  More specifically, the blood flow non-display condition in the data selection unit 154 satisfies all of the speed condition “V <Vth2”, the power condition “Pp> Ppth2”, and the dispersion condition “Tp <Tpth”. That is, “Pp> Ppth2 & Tp <Tpth & V <Vth2” is set as the blood flow non-display condition, and the points (V, T, P) is replaced with an index “0” indicating no blood flow. This further suppresses erroneous detection in which a portion that is originally blood flow is regarded as having no blood flow. As a result, the blood flow is displayed more clearly.

  In addition, in the data selection unit 154 of the present embodiment, a second blood flow non-display condition is set in addition to the blood flow non-display condition, and the data selection unit 154 sets the second blood flow non-display condition. For the matching points, the index (V, T, P) is replaced with an index “0” indicating that there is no blood flow. As the second blood flow non-display condition, a second power condition “P <Pth”, a second speed condition “V <Vth1”, and a third power condition “Pp <Ppth1” are set. The second power condition is a condition that the power Pp obtained by the pre-attenuation correlation calculation unit 156 exceeds the fourth threshold value Ppth1. The second velocity condition is a condition that the blood flow velocity V obtained by the post-attenuation correlation calculation unit 153 is lower than the fifth threshold value Vth1. The third power condition is a condition that the power P obtained by the post-attenuation correlation calculation unit 153 is lower than the sixth threshold Pth.

[Second blood flow non-display condition]
In the data selection unit 154, in addition to the blood flow non-display condition, the second power condition “P <Pth”, the second speed condition “V <Vth1”, and the second blood flow non-display condition Even when any one of at least one condition selected from the three power conditions “Pp <Ppth1” is met, the index is replaced with an index “0” indicating that there is no blood flow. More specifically, in the data selection unit 154, in addition to the blood flow non-display condition, the second power condition “P <Pth”, the second speed condition “V <Vth1”, and the third power condition When any one of at least one condition selected from the above is satisfied, the index is replaced with an index “0” indicating that there is no blood flow.

  More specifically, the data selection unit 154 includes, as the second blood flow non-display condition, the second power condition “P <Pth”, the second speed condition “V <Vth1”, and the third power condition “ When any of Pp <Ppth1 ”matches, the index out is replaced with an index“ 0 ”indicating that there is no blood flow. That is, the second blood flow non-display condition is “P <Pth + V <Vth1 + Pp <Ppth1”. Here, “+” means a logical sum (OR).

  The power Pp determined by the pre-attenuation correlation calculation unit 156 determined under the second power condition is based on the received signal before attenuation by the MTI filter 152. In this case, the power Pp includes a clutter component without being attenuated. In a state where there is no attenuation by the MTI filter 152, the magnitude of the power Pp caused by the clutter is larger than the magnitude of the power Pp caused by the blood flow. That is, when the second power condition that the power Pp exceeds the fourth threshold value Ppth1 is met, the display of clutter can be suppressed by performing the replacement with the index “0”.

  Here, since the fourth threshold value Ppth1 is larger than the third threshold value Ppth2, even when the power Pp does not exceed the fourth threshold value Ppth1, the blood using the third threshold value Ppth2 different from this condition is used. Since the clutter is determined to be clutter when the flow non-display conditions are met, the clutter is more accurately determined according to the multifaceted conditions. Further, the fifth threshold value Vth1 used in the second speed condition is smaller than the second threshold value Vth2. For this reason, even when the velocity V does not fall below the fifth threshold value Vth1, it is determined that it is a clutter if the blood flow non-display condition using the second threshold value Vth2 is different from this condition. Therefore, the clutter can be more accurately determined according to the multifaceted conditions.

  FIG. 6 is a diagram illustrating a display example of an image by the ultrasonic diagnostic apparatus. Part (A) of FIG. 6 is an image as a comparative example by the conventional ultrasonic diagnostic apparatus shown in FIG. 1, and Part (B) is an image by the ultrasonic diagnostic apparatus of the present embodiment shown in FIGS. It is. Both images are obtained by simulating the processing by both ultrasonic diagnostic apparatuses for the same received signal. However, tomographic image processing is omitted. The simulation result is originally a color image in which the direction of blood flow is displayed by color. The image is at the position of the hepatic vein, and the upper edge of the image shows the position of the ultrasonic probe (probe) in the ultrasonic diagnostic apparatus, that is, the body surface, and shows the deep part as it goes downward Yes.

  In the image of part (A) of FIG. 6 by a conventional ultrasonic diagnostic apparatus, clutter b, which is noise, appears strongly at a position adjacent to the blood flow in the hepatic vein a. On the other hand, in the image of part (B) of FIG. 6 by the ultrasonic diagnostic apparatus of the present embodiment, the blood flow in the hepatic vein a is maintained at a level sufficient for recognition, and the clutter b decreases. As a result, the state of blood flow in the hepatic vein a can be clearly determined.

  In the above-described embodiment, as an example of the data selection unit according to the present invention, the data selection unit 154 in which the second blood flow non-display condition is set in addition to the blood flow non-display condition is shown. However, the present invention is not limited to this. For example, the second blood flow non-display condition may not be set.

  In the above-described embodiment, as an example of the data selection unit according to the present invention, the data selection unit 154 that satisfies the condition of the speed condition and the power condition is shown in addition to the dispersion condition. However, the present invention is not limited to this. For example, as the blood flow non-display condition, only the dispersion condition may be used, or one of the speed condition and the power condition may be combined. Good.

DESCRIPTION OF SYMBOLS 10 Ultrasonic diagnostic apparatus 15 Color Doppler processing part 151 Quadrature detection part 152 MTI filter 153 Post-attenuation correlation calculation part 154 Data selection part 156 Pre-attenuation correlation calculation part 16 DSC part 17 Display apparatus Ppth1 4th threshold value Ppth2 3rd threshold value Pth 6th threshold value Tpth 1st threshold value Vth1 5th threshold value Vth2 2nd threshold value

Claims (3)

The ultrasonic pulse transmission into the subject and the reception of the reflected ultrasonic wave reflected and returned within the subject are repeated a plurality of times, and the inside of the subject is determined based on the received signal obtained during this repetition. In the ultrasonic diagnostic apparatus for displaying blood flow at each point in the ultrasonic transmission / reception area
An MTI filter that attenuates the clutter component in the received signal including both the clutter component and the blood flow component by attenuating the low-frequency component in the received signal;
A pre-attenuation correlation calculation unit for obtaining a dispersion value and power of a velocity at each point from a reception signal before attenuation of a clutter component in the MTI filter;
A post-attenuation correlation calculation unit for obtaining a blood flow velocity at each point from the signal after attenuation by the MTI filter;
An image display unit for displaying an image representing blood flow at each point;
Wherein among the points, together with the variance value determined by the attenuation before correlation calculation unit matches a dispersed condition below a first threshold value, further, said movement speed obtained by the attenuation after correlation calculator When the blood flow non-display condition is that the speed condition below the second threshold and the power obtained by the pre-attenuation correlation calculation unit match at least one of the power conditions exceeding the third threshold blood indices obtained by the attenuation after correlation calculation unit for points that match the blood flow non-display condition after having replaced the index representing that there is no blood flow, on the image display unit on the basis of the index An ultrasonic diagnostic apparatus comprising: a display control unit that displays an image representing a flow. The display control unit sets the blood flow non-display condition to match all of the speed condition, the power condition, and the dispersion condition, and a point that matches the blood flow non-display condition is after the attenuation. The index obtained by the correlation calculation unit is replaced with an index indicating that there is no blood flow, and an image representing blood flow is displayed on the image display unit based on the index. Item 2. The ultrasonic diagnostic apparatus according to Item 1. The display control unit has a second power condition in which the power calculated by the pre-attenuation correlation calculation unit exceeds a fourth threshold value greater than the third threshold value, and the blood flow velocity calculated by the post-attenuation correlation calculation unit. At least one selected from a second speed condition that falls below a fifth threshold value that is smaller than the second threshold value, and a third power condition that the power required by the post-attenuation correlation calculation unit falls below a sixth threshold value Matching any one of the two conditions is set as the second blood flow non-display condition, and for the point meeting the second blood flow non-display condition, the index is used as an index indicating that there is no blood flow. The ultrasonic diagnostic apparatus according to claim 1 or 2, wherein an image representing blood flow is displayed on the image display unit based on the index after replacement.

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