JP4499477B2 - Ultrasonic diagnostic equipment - Google Patents

Description

  The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to adaptive setting of transmission conditions and pulse compression processing.

The mechanical index value (hereinafter referred to as “MI value”) is a value indicating the influence of ultrasound on the medium in the living body. The MI value is generally defined as follows. Here, P _N is the negative sound pressure peak value in the medium, and f _C is the transmission center frequency.
_{MI = P N / √f c ···} (1)

P _N depends on the direction of the polarity of transmission voltage applied to the piezoelectric element, but here, assuming that the transmission voltage is applied to the piezoelectric element so that the negative voltage peak value V _N generates P _N (2 ).

P _N = α · V _N (2)

  However, α is a proportionality constant depending on the conversion efficiency of the piezoelectric element, the attenuation in the medium, and the transmission focus state. Thus, equation (1) can be expressed as equation (3).

MI = α (V _N / √f _c ) (3)

  From the viewpoint of biological safety, an upper limit is usually set for the MI value. For example, the transmission voltage is set by the user so that the MI value does not exceed the upper limit.

  By the way, recently, an ultrasound contrast agent is injected into the body, and the ultrasound contrast agent is imaged. The ultrasonic contrast agent is constituted by, for example, microbubbles (microbubbles), and when it receives a certain level of ultrasonic power, it bursts and disappears, and a strong reflected wave is generated at that time. When performing ultrasound diagnosis by circulating the ultrasound contrast agent in the body, transmission that does not rupture the ultrasound contrast agent (or reduce the destruction rate) and continuously observes the behavior of the ultrasound contrast agent (non-destructive) (Transmission mode) and transmission (destructive transmission mode) in which the ultrasound contrast agent is destroyed (or the destruction rate is increased) and the state of the body at that time is observed (destructive transmission mode). 1). In the former non-destructive transmission mode, the transmission voltage is lowered (in other words, transmission with a small MI value is performed), and in the latter destructive transmission mode, the transmission voltage is increased (in other words, transmission with a large MI value). Is done).

  As described above, when the MI value is lowered or the MI value is lowered for non-destructive transmission due to the safety of the living body, the amplitude value in the ultrasonic pulse is reduced, resulting in an image. It is pointed out that the sensitivity of the system will decrease.

JP 2002-306477 A JP-A-9-187457 JP-T 2002-539881 Matthew O'Donnell, "Coded Excitation System for Improving the Penetration of Real-Time Phased -Array Imaging Systems", IEEE Trans., UFFC, vol. 39, No. 3, May 1992

  As described above, when the MI value is lowered or the MI value is lowered for non-destructive transmission due to the safety of the living body, the amplitude value in the ultrasonic pulse is reduced, resulting in an image. It is pointed out that the sensitivity of the system will decrease. Even if the MI value is varied, it is desirable to maintain a good image or to reduce or prevent a decrease in image sensitivity. Each of the above prior art documents describes that transmission conditions and pulse compression conditions are adaptively set or that sensitivity is automatically adjusted in relation to a mechanical index value or a corresponding value. It has not been.

  An object of the present invention is to maintain the image quality of an ultrasonic image or to reduce the deterioration of the image quality even if the MI value or a value corresponding thereto changes.

  Another object of the present invention is to use a pulse compression technique to compensate for a sensitivity decrease accompanying a decrease in MI value.

  Another object of the present invention is that the MI value can be directly specified by the user based on the relationship with the ultrasound contrast agent or the biological safety, and the appropriate device operating conditions are automatically set according to the user specification. There is to be done.

(1) The present invention relates to a transducer for transmitting an ultrasonic pulse and receiving a reflected wave and outputting a received signal, and a mechanical index value representing the influence of the ultrasonic pulse on the medium or a value corresponding thereto. A setting value determining unit that determines a setting value; a transmission / reception control unit that sets a transmission condition including a waveform length of the ultrasonic pulse based on the setting value; and a pulse compression condition that matches the transmission condition; A transmission unit that generates a transmission signal according to the transmission condition and outputs the transmission signal to the transducer; a pulse compression processing unit that applies a pulse compression process to the reception signal from the transducer according to the pulse compression condition; And an image forming unit that forms an ultrasonic image based on the received signal after the pulse compression.

  According to the above configuration, when the mechanical index value (MI value) or the set value equivalent to it is changed, the waveform length is changed and the pulse compression condition is changed. Therefore, the waveform length can be varied in conjunction with the MI value. Whether the ultrasonic contrast agent is used or not, the waveform length can be automatically variably set according to the set value.

  Preferably, the set value may be continuously or stepwise changed from a small value that does not destroy the ultrasound contrast agent administered to the living body to a large value that destroys the ultrasound contrast agent. The transmission / reception control unit increases the waveform length when the set value is small, and decreases the waveform length when the set value is large. According to this configuration, when using an ultrasound contrast agent, destructive transmission and non-destructive transmission can be performed, and the image sensitivity can be maintained by resetting the waveform length when changing such a transmission mode, Or a sensitivity fall can be reduced.

  Preferably, the transmission / reception control unit adaptively sets the waveform length according to the size of the set value so that the sensitivity maintaining condition is satisfied.

  Preferably, the set value determining unit includes an operation unit for variably setting the set value by a user. The operation unit may be a knob, a slider, a numerical value input device, or the like that directly designates the MI value or designates its variable amount.

  Preferably, the ultrasonic pulse is a chirp pulse whose frequency changes with time, and the waveform length of the chirp pulse is adaptively set according to the set value.

(2) The present invention relates to a transducer that transmits an ultrasonic pulse into a living body to which an ultrasonic contrast agent is administered, receives a reflected wave from the living body, and outputs a reception signal; Non-destructive transmission mode using an ultrasonic pulse with a low transmission voltage that does not destroy the ultrasonic contrast agent, and a destructive transmission mode using an ultrasonic pulse with a high transmission voltage enough to destroy the ultrasonic contrast agent Selecting means for selecting a transmission mode from a plurality of transmission modes, and a waveform for increasing the waveform length of the ultrasonic pulse in the non-destructive transmission mode and reducing the waveform length of the ultrasonic pulse in the destructive transmission mode. It includes a length control means, and a pulse compression processing unit that applies a pulse compression process to the received signal using a pulse compression coefficient sequence corresponding to the waveform length.

  Preferably, the waveform length control means sets a waveform length in each transmission so that sensitivity is substantially maintained in the non-destructive transmission mode and the destructive transmission mode.

  Preferably, the selection means is a means for changing a mechanical index value related to a degree of destruction of the ultrasonic contrast agent, and the transmission voltage is lowered and the waveform length is increased as the mechanical index value is decreased. The larger the mechanical index value, the higher the transmission voltage and the shorter the waveform length.

(3) The present invention relates to a transmitter / receiver for transmitting an ultrasonic pulse into a living body to which an ultrasonic contrast agent is administered and receiving a reflected wave from the living body and outputting a received signal, and an operation panel. An index value designating unit for variably setting a mechanical index value representing the influence of an ultrasonic pulse on a biological tissue and an ultrasonic contrast agent continuously or stepwise by a user, and the user-set mechanical A transmission control unit that adaptively sets a transmission condition including a transmission voltage and a waveform length of the ultrasonic pulse according to an index value, and a pulse compression coefficient sequence corresponding to the waveform length. And a pulse compression processing unit that performs pulse compression processing.

  Preferably, image forming means for forming an ultrasonic image based on the received signal, and display processing means for displaying the mechanical index value on the screen together with the ultrasonic image are included. If the MI value is displayed on the screen, the MI value can be observed together with the ultrasonic image, so that the user can recognize the measurement conditions. Note that other information such as the waveform length may be displayed simultaneously.

  As described above, according to the present invention, it is possible to maintain the image quality of the ultrasonic image or to reduce the deterioration of the image quality even if the MI value or a value corresponding thereto changes. According to the present invention, it is possible to compensate for a sensitivity decrease accompanying a decrease in MI value by using a pulse compression technique. Alternatively, according to the present invention, the MI value can be directly designated by the user from the relationship with the ultrasound contrast agent or the biological safety, and the appropriate operating condition of the apparatus is automatically set according to the user designation. Can be set.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

First, the basic concept in the present embodiment will be described. Consider a case where the current MI value is changed by the user or automatically and multiplied by β. However, 0 <β ≦ 1.0, that is, β is smaller than 1.0. In such a case, the image sensitivity is lowered by 10 · Log (1 / β) ² [dB]. Therefore, it is considered to compensate for this lack of sensitivity using the pulse compression method.

  Let T be the waveform length of the transmission waveform before sensitivity compensation (the waveform length is generally defined by the time length between positions down from the waveform peak by a predetermined level, but other definitions corresponding thereto may be adopted. ), The band is B = 1 / T. Here, the TB product before sensitivity compensation is set to 1. Assuming that the MI value is made small, when maintaining the transmission band B and changing (increasing) the transmission waveform length T to maintain the sensitivity, if the waveform length after sensitivity compensation is T ′, (4) may be satisfied.

10 · Log (T ′ · B) = 10 · Log (1 / β) ²
T ′ = 1 / (β ² · B) (4)

  Therefore, if pulse transmission and pulse compression are performed using a transmission waveform having a waveform length T ′ and a bandwidth B defined by equation (4), it is possible to compensate for a decrease in sensitivity caused by reducing the MI value. That is, the decrease in sensitivity is covered by an increase in the waveform length. Conversely, if the MI value is increased and the sensitivity is maintained, the waveform length may be reduced.

  For example, when a linear FM signal is used, a waveform that sweeps the frequency by B over time T ′ may be used as in the following equation (5).

x (t) = β · V N · sin {(2πf c -πB) t + (πB / T ') t 2}
... (5)

In the pulse compression filter, a coefficient sequence corresponding to this transmission waveform may be set. In the case of a matched filter, the impulse response h (t) of the pulse compression filter may be expressed by the following equation (6). Where x ^* is a complex conjugate and τ is a delay time.

h (t) = x ^* (τ−t) (6)

When the pulse compression filter processing is executed in the frequency domain processing, the Fourier transform X (ω) of the equation (5) is obtained for the impulse response of the pulse compression filter, and the complex conjugate X ^* (ω) is obtained. Good.

From the viewpoint of the depth of field obtained from the allowable phase error, the waveform length T ′ is restricted by the following equation (7). Here, f _# is an f-number obtained by the focal length / aperture length.

_{T '<(16 · f #} 2) / f c ··· (7)

  As described above, from the viewpoint of maintaining the TB product, the image quality can be maintained even when the MI value is changed by adaptively setting the waveform length when the MI value is changed. In particular, since the pulse compression is performed even when the waveform length is increased, the problem of a reduction in image resolution can be avoided or alleviated.

  FIG. 1 conceptually shows the method according to the present embodiment. Reference numeral 10 represents a variable setting of the MI value. The MI value can be manually specified by the user 12. In this case, for example, the upper limit of the MI value determined from the viewpoint of biological safety can be set to 100%, and the MI value can be set between 0 to 100%, or its variable rate can be set. Of course, even when the ultrasound contrast agent is not injected into the living body, the MI value can be variably set from the viewpoint of the necessity of diagnosis or the safety of the living body.

  When performing ultrasonic diagnosis using an ultrasonic contrast agent, the destructive transmission mode 14 and the non-destructive transmission mode 16 can be selected. In this case, such a transmission mode may be switched and set manually, or the transmission mode may be automatically switched alternately as indicated by reference numeral 18.

  When the MI value is changed, particularly when the MI value is changed to a small value, the image quality of the ultrasonic wave changes. Specifically, when the MI value decreases, the image quality sensitivity decreases. Therefore, the user feels uncomfortable at the time of switching the MI value, or hinders ultrasonic diagnosis. Therefore, in this embodiment, the waveform length is variably set as described below so as to maintain the image sensitivity when the MI value is changed.

Specifically, the ratio β (20) between the current MI value and the changed MI value is obtained as described above, and β is assumed to be a value smaller than 1.0. On the other hand, the band B (22) is fixedly or variably set, and a new waveform length T ′ (24) is obtained before and after the change of the MI value according to the above equation (2). On the other hand, the transmission voltage 26 is linked to the MI value. When the transmission condition 28 constituted by the waveform length T ′ (24) and the transmission voltage 26 is determined, a transmission waveform is newly generated as indicated by reference numeral 30 in accordance with the transmission condition 28. Specifically, the transmission waveform is represented by reference numeral 100. Reference numeral 104 represents an envelope of a transmission waveform. In this embodiment, the transmission waveform is a chirp pulse, and the frequency of the transmission waveform varies along the time axis in the envelope 104. Specifically, the transmission frequency linearly changes over f _{1 to} f ₂ . Band B is defined as the width of such frequency variation. Incidentally, the waveform length T is defined as the width on the time axis between two points that are lowered by a predetermined level from the peak of the transmission waveform. The above V _N is defined as the peak voltage on the negative side. Note that the envelope 104 may have a Gaussian shape.

  Therefore, decreasing the MI value results in an increase in waveform length and maintenance of image sensitivity. When the MI value is increased, the waveform length is reduced from the viewpoint of maintaining image sensitivity. As described above, even when the MI value is changed, the image quality or the appearance of the image is maintained, so that the user does not feel uncomfortable or the ultrasonic diagnosis can be performed smoothly.

  When the waveform length changes, it is also necessary to change the pulse compression condition for the received signal. For this reason, a new coefficient string for pulse compression is generated as shown by reference numeral 32 and sent to the pulse compression filter. In this case, pulse compression may be performed on the time axis, or pulse compression may be performed on the frequency axis. A coefficient sequence is generated in accordance with such a pulse compression processing method. Since pulse compression is performed even when the waveform length is increased, problems such as a reduction in image resolution are avoided.

  FIG. 2 is a block diagram showing a preferred embodiment of the ultrasonic diagnostic apparatus according to this embodiment. In the ultrasonic diagnostic apparatus shown in FIG. 2, the above method is applied to adaptively set the waveform length.

  The array transducer 40 is provided in a probe (not shown). The array transducer 40 is a linear array of a plurality of transducer elements. Of course, a 2D array transducer in which a plurality of transducer elements are two-dimensionally arranged can also be used. An ultrasonic beam is formed by the array transducer 40, and the ultrasonic beam is electronically scanned. As the electronic scanning method, electronic sector scanning, electronic linear scanning, and the like are known.

  The transmission unit 42 functions as a transmission beam former. That is, a plurality of transmission signals are supplied from the transmission unit 42 to a plurality of vibration elements. Thereby, an ultrasonic pulse (chirp pulse) is emitted from the array transducer 40 into the living body. The reflected wave from the living body is received by the array transducer 40. Thereby, a plurality of reception signals are output from the plurality of vibration elements.

  Those received signals are input to the receiving unit 54. The receiving unit 54 functions as a reception beam former. That is, phasing addition processing or the like is applied to a plurality of received signals, and the received signals after phasing addition are output to the signal processing unit 56.

  The signal processing unit 56 includes a pulse compression filter 58 in the present embodiment. The pulse compression filter 58 performs pulse compression on the received signal. The received signal after pulse compression is output from the signal processing unit 56 to a DSC (digital scan converter) 60. The DSC 60 has a coordinate conversion function, a data interpolation function, an image composition function, and the like. An ultrasonic image is constructed by the DSC 60, and image data of the ultrasonic image is displayed on the display unit 62. An ultrasonic image is displayed on the display unit 62.

  Ultrasound images include various images such as B-mode images (two-dimensional tomographic images), color flow mapping images (two-dimensional blood flow images), color tissue images (tissue motion display images), power Doppler images, and three-dimensional images. Can be raised. In the present embodiment, the set MI value can be represented by numerical values or other display forms on the ultrasonic image.

  The operation panel 50 has a keyboard, a trackball, and the like. In the present embodiment, the operation panel 50 is provided with an MI value variable device 52. The MI value variable device 52 is an input device such as a dial or a slider. Of course, the MI value may be directly input as a numerical value using a keyboard or the like. Alternatively, the variable rate may be input instead of the MI value itself.

  The transmission / reception control unit 44 includes a host controller or the like, and the transmission / reception control unit 44 controls operations of the transmission unit 42, the reception unit 54, the signal processing unit 56, and the like. An operation panel 50 is connected to the transmission / reception control unit 44.

  The waveform length setting unit 46 included in the transmission / reception control unit 44 determines a new waveform length in accordance with the change of the MI value according to the process shown in FIG. A coefficient sequence generation unit 48 provided in the transmission / reception control unit 44 newly generates a coefficient sequence for pulse compression that matches a newly set waveform length, that is, a newly generated transmission waveform. The coefficient sequence is output to the pulse compression filter 58. Incidentally, a table or the like may be provided in the transmission / reception control unit 44 so that when the above β, B, or the like is input, the waveform length T ′ corresponding to the combination thereof can be directly obtained. Further, a signal for selecting a waveform length or a transmission waveform may be output. In other words, the process shown in FIG. 1 conceptually represents the determination of the waveform length and the like, and in an actual apparatus, each of those steps may be realized by software processing or by hardware processing. May be. One or a plurality of processes may be realized using a memory table or the like.

  Incidentally, it is desirable to use the above-described linear FM waveform as a pulse compression method, but in addition, binary code waveforms such as a Baker code waveform, a Golay code waveform, and an M-sequence code waveform can also be used. . When such a binarized code is used, the waveform length can be manipulated in the same manner as described above by changing the code length (corresponding to the waveform length). The position of pulse compression may be performed inside the reception unit 54 as a reception beam former, or pulse compression may be applied to the signal after detection. When a pulse compression process is provided in the reception unit, the pulse compression process may be performed for each channel. Each time the MI value is changed, the transmission waveform and the coefficient sequence may be obtained by recalculation. However, as described above, the coefficient sequence may be read from the table. In the above embodiment, since the MI value or data corresponding thereto is displayed on the ultrasonic image, there is an advantage that the current MI value can be directly recognized when observing the ultrasonic image.

  The transmission unit 42 illustrated in FIG. 2 includes a plurality of transmitters provided for each channel. An example of such a transmitter is shown in FIG. The waveform memory 64 is constituted by a RAM or the like, for example, and the generated transmission waveform data is stored on the waveform memory 64. The data is read out, delayed by the delay generator 66, and input to the D / A converter 68. Incidentally, the delay processing can be realized by changing the read timing to the waveform memory 64, or the delay processing by the delay generator 66 may be performed at the subsequent stage of the waveform memory 64 as shown in FIG. The waveform data is converted from a digital signal to an analog signal by the D / A converter 68, the transmission waveform as an analog signal is linearly amplified by the amplifier 70, and the generated transmission signal for driving is supplied to the corresponding vibration element. Is done.

  FIG. 4 shows a configuration example of the signal processing unit 56 shown in FIG. The received signal after the phasing addition is input to the pulse compression filter 58 as described above. The received signal after pulse compression is input to the detector 59. The detector 59 may be an envelope detector or a quadrature detector. The output signal of the detector 59 is input to a plurality of processing modules 65A, 65B, 65C. These processing modules 65A, 65B, and 65C may be B-mode image generation modules, color flow mapping image formation processing modules, and other processing modules for forming images.

  FIG. 5 shows a specific example of the pulse compression filter 58. In the example shown in FIG. 5, pulse compression processing is performed on the frequency axis. That is, a reception signal as a complex signal or a real number signal is input to the complex FFT 71, and thereby converted from a signal on the time axis to a signal on the frequency axis. The complex multiplier 72 is a circuit that individually multiplies the coefficient sequence for pulse compression in both the real part and the imaginary part. The signal after the multiplication is input to the complex inverse FFT 74. The complex inverse FFT 74 converts the signal after pulse compression from the frequency axis to the time axis.

  FIG. 6 shows a configuration for performing pulse compression processing on the time axis. Here, the pulse compression filter 58 is configured as an FIR filter 76. The signal on the time axis is sequentially multiplied by a coefficient sequence, whereby pulse compression processing is performed.

  As described above, according to the ultrasonic diagnostic apparatus of this embodiment, when the MI value or a value corresponding thereto is set by the user or automatically, the waveform length is reset according to the value. In particular, the waveform length is appropriately set so as to maintain the image sensitivity. Even when the MI value is lowered and the transmission voltage is lowered, the waveform length is increased, and as a result, the sensitivity of the ultrasonic image is maintained as described above. As described above, the combination of the variable setting of the MI value and the pulse compression technique is significant, and there is an advantage that an apparatus having extremely high practical value can be configured for the user.

It is a conceptual diagram which shows the concept of the processing process which concerns on this invention. 1 is a block diagram showing an overall configuration of an ultrasonic diagnostic apparatus according to the present embodiment. It is a figure which shows the specific structural example of a transmitter. It is a block diagram which shows the specific structural example of a signal processing part. It is a figure which shows an example of a pulse compression filter. It is a figure which shows the other example of a pulse compression filter.

Explanation of symbols

  10 MI value variable, 12 users, 14 destructive transmission mode, 16 nondestructive transmission mode, 24 waveform length T ′, 26 transmission voltage, 28 transmission condition, 30 transmission waveform generation, 32 pulse compression coefficient sequence, 100 transmission waveform ( Chirp pulse).

Claims (10)

A transducer for transmitting an ultrasonic pulse and receiving a reflected wave and outputting a received signal;
A set value determining unit for determining a set value as a mechanical index value representing an influence of an ultrasonic pulse on the medium or a value corresponding thereto;
Setting a transmission condition including the waveform length of the ultrasonic pulse based on the set value, and a transmission / reception control unit for setting a pulse compression condition suitable for the transmission condition;
A transmission unit that generates a transmission signal according to the transmission condition and outputs the transmission signal to the transducer; and
In accordance with the pulse compression conditions, a pulse compression processing unit that performs a pulse compression process on the received signal from the transducer,
An image forming unit that forms an ultrasonic image based on the received signal after the pulse compression;
An ultrasonic diagnostic apparatus comprising: The apparatus of claim 1.
The set value can be changed continuously or stepwise from a small value that does not destroy the ultrasound contrast agent administered to the living body to a large value that destroys the ultrasound contrast agent. ,
The ultrasonic diagnostic apparatus, wherein the transmission / reception control unit increases the waveform length when the set value is small, and decreases the waveform length when the set value is large. The apparatus according to claim 1 or 2,
The ultrasonic diagnostic apparatus, wherein the transmission / reception control unit adaptively sets the waveform length according to a size of the set value so that a sensitivity maintenance condition is satisfied. The apparatus of claim 1.
The ultrasonic diagnostic apparatus, wherein the set value determining unit includes an operation unit for variably setting the set value by a user. The apparatus of claim 1.
The ultrasonic pulse is a chirp pulse whose frequency changes with time,
The ultrasonic diagnostic apparatus, wherein a waveform length of the chirp pulse is adaptively set according to the set value. A transducer for transmitting an ultrasonic pulse into a living body to which an ultrasonic contrast agent is administered and receiving a reflected wave from the living body and outputting a reception signal;
At least, a non-destructive transmission mode using an ultrasonic pulse with a low transmission voltage that does not destroy the ultrasonic contrast agent, and a destruction using an ultrasonic pulse with a high transmission voltage enough to destroy the ultrasonic contrast agent A selection means for selecting a transmission mode from a plurality of transmission modes including a transmission mode;
Waveform length control means for increasing the waveform length of the ultrasonic pulse in the non-destructive transmission mode and reducing the waveform length of the ultrasonic pulse in the destructive transmission mode;
Using a pulse compression coefficient sequence corresponding to the waveform length, a pulse compression processing unit that performs pulse compression processing on the received signal;
An ultrasonic diagnostic apparatus comprising: The apparatus of claim 6.
The ultrasonic diagnostic apparatus, wherein the waveform length control means sets a waveform length in each transmission so that sensitivity is substantially maintained in the non-destructive transmission mode and the destructive transmission mode. The apparatus of claim 6.
The selection means is means for changing a mechanical index value related to the degree of destruction of the ultrasound contrast agent,
The smaller the mechanical index value, the lower the transmission voltage and the larger the waveform length; the larger the mechanical index value, the higher the transmission voltage and the smaller the waveform length;
An ultrasonic diagnostic apparatus. A transducer for transmitting an ultrasonic pulse into a living body to which an ultrasound contrast agent has been administered and receiving a reflected wave from the living body and outputting a received signal;
An index value designating unit which is provided on the operation panel and is variably set by a user continuously or stepwise for a mechanical index value representing the influence of an ultrasonic pulse on a living tissue and an ultrasonic contrast agent;
Transmission control means for adaptively setting a transmission condition including a transmission voltage and a waveform length of the ultrasonic pulse according to the mechanical index value set by the user,
A pulse compression processing unit that performs pulse compression processing on the received signal using a pulse compression coefficient sequence corresponding to the waveform length;
An ultrasonic diagnostic apparatus comprising: The apparatus of claim 9.
Image forming means for forming an ultrasonic image based on the received signal;
Display processing means for displaying the mechanical index value on the screen together with the ultrasonic image;
An ultrasonic diagnostic apparatus comprising:

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