JP2015062483A - Ultrasonic diagnostic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic diagnostic equipment that reduces a burden of a user operation in optimizing beam formation processing, and optimizes the beam formation processing while forming an ultrasonic image for diagnosis.SOLUTION: A reception beam former 14 for diagnosis forms a diagnosis beam based on a received wave signal acquired from a probe 10. An image forming part 20 forms an ultrasonic image based on a reception signal acquired along the diagnosis beam. A reception beam former 16 for evaluation forms an evaluation beam by beam forming processing based on a sound velocity value for each sound velocity value of a plurality of sound velocity values based on the received wave signal acquired from the probe 10. An evaluation selection part 40 selects an appropriate sound velocity value out of the plurality of sound velocity values based on a reception signal acquired along the evaluation beam. A control part 50 controls the reception beam former 14 for diagnosis so as to form a diagnosis beam by beam forming processing based on the appropriate sound velocity value from a time phase after the appropriate sound velocity value is selected.

Description

  The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to a technique for optimizing an ultrasonic beam forming process.

  A general ultrasonic diagnostic apparatus includes a plurality of vibration elements, and forms a transmission beam of ultrasonic waves by delaying transmission signals supplied to the plurality of vibration elements. The received signal is delayed and added (phasing addition process) to form an ultrasonic reception beam. In forming the transmission beam and the reception beam, the sound speed value in the living body is used particularly when determining the delay amount for each vibration element. For example, 1530 m / s is used as the sound velocity value in the living body.

  However, since the sound velocity value in the living body changes depending on the properties of the tissue in the living body, for example, if a transmission beam or a reception beam is always formed on the assumption of a constant sound velocity value, an appropriate transmission beam may be used depending on the diagnosis situation. Or reception beam may not be realized, and reception sensitivity, image resolution, and the like may be reduced.

  For this reason, techniques for appropriately correcting the sound velocity value of ultrasonic waves have been proposed. For example, Patent Document 1 describes an ultrasonic diagnostic apparatus in which an operator changes an ultrasonic sound speed value while searching for an ultrasonic image and searches for an ultrasonic sound speed value at which the amplitude of a received signal is maximized. Yes. Patent Document 2 describes an ultrasonic diagnostic apparatus that performs sound speed calibration as a parameter that defines a delay condition during a test operation.

  However, in the apparatus of Patent Document 1, an operator (user) is burdened with operations when changing the ultrasonic sound velocity value. Further, in the apparatus of Patent Document 2, since the sound speed calibration is performed during the test operation, it is difficult to correct the sound speed in real time while forming an ultrasonic image for diagnosis.

JP-A-8-317926 JP 2010-119481 A

  In view of the background art described above, the inventor of the present application has repeatedly researched and developed a technique for optimizing ultrasonic beam forming processing.

  The present invention has been made in the course of research and development, and an object thereof is to reduce the burden of user operation in optimizing the beam forming process. Another object of the present invention is to optimize the beam forming process while forming an ultrasonic image for diagnosis.

  An ultrasonic diagnostic apparatus suitable for the above-described object includes a probe that transmits and receives ultrasonic waves, a diagnostic beam forming unit that forms an ultrasonic diagnostic beam based on a received signal obtained from the probe, and a diagnostic beam that is obtained along the diagnostic beam. An image forming unit that forms an ultrasonic image based on the received signal, and an ultrasonic evaluation by beam forming processing based on the sound speed value for each sound speed value of the plurality of sound speed values based on the received signal An evaluation beam forming unit that forms a beam; an evaluation selection unit that selects an appropriate sound speed value from the plurality of sound speed values based on a reception signal obtained along the evaluation beam; and after the appropriate sound speed value is selected. And a control unit that controls the diagnostic beam forming unit so as to form a diagnostic beam by beam forming processing based on the appropriate sound velocity value.

  In the above apparatus, the diagnostic beam forming unit and the evaluation beam forming unit may be realized by hardware different from each other, for example, and the function of the diagnostic beam forming unit and the evaluation beam forming unit are obtained by time-sharing processing of the same hardware. The function may be realized.

  According to the above apparatus, the evaluation beam forming unit forms an evaluation beam by beam forming processing based on the sound speed value for each sound speed value of the plurality of sound speed values, so there is no need for the user to change the sound speed. The burden of user operation is reduced. In addition, an ultrasonic image is formed by the diagnostic beam formed by the diagnostic beam forming unit, and an appropriate sound speed value is selected by the evaluation beam formed by the evaluation beam forming unit, so that an ultrasonic image for diagnosis is formed. The beam forming process can be optimized.

  In a preferred embodiment, the diagnostic beam forming unit forms a plurality of diagnostic frames over a plurality of time phases by scanning the diagnostic beam, and the evaluation beam forming unit scans the evaluation beam, Each of which forms a plurality of evaluation frames corresponding to the time phases of the respective diagnostic frames, and the evaluation selection unit selects an appropriate sound velocity value based on received signals obtained over a plurality of evaluation frames, and the control unit Controlling the diagnostic beam forming unit so as to form a diagnostic beam by a beam forming process based on the appropriate sound velocity value from a diagnostic frame corresponding to a time phase immediately after the appropriate sound velocity value is selected. Features.

  In a preferred embodiment, the evaluation beam forming unit forms an evaluation beam for each evaluation frame by a beam forming process based on a sound speed value corresponding to the evaluation frame, and the evaluation selecting unit includes the plurality of sound speed values. An appropriate sound velocity value is selected based on evaluation values obtained from a plurality of evaluation frames corresponding to the above.

  In a preferred embodiment, the ultrasonic diagnostic apparatus includes a region-of-interest setting unit that sets one or a plurality of regions of interest in each evaluation frame, and the evaluation selection unit includes the region of interest for each region of interest. An appropriate sound velocity value in the region is selected.

  In a preferred embodiment, the probe includes a plurality of vibration elements each transmitting and receiving ultrasonic waves, and the evaluation beam forming unit uses a delay data set composed of delay data related to each of the plurality of vibration elements, An evaluation beam is formed using a delay data set based on each sound speed value, and the evaluation selecting unit calculates an appropriate sound speed value from the plurality of sound speed values based on a received signal obtained along the evaluation beam. The diagnostic beam forming unit is configured to form a diagnostic beam using a delay data set based on the appropriate sound velocity value from a time phase after the appropriate sound velocity value is selected.

  According to the present invention, the burden of user operation is reduced in optimizing the beam forming process. Further, according to the present invention, it is possible to optimize the beam forming process while forming an ultrasonic image for diagnosis.

1 is a functional block diagram showing an overall configuration of a preferable ultrasonic diagnostic apparatus of the present invention. It is a figure which shows the specific example which concerns on selection of the optimal sound speed value. It is a figure which shows the specific example of a several region of interest (ROI). It is a figure which shows the specific example of the process which concerns on selection of the optimal sound speed value in two regions of interest set to the depth direction.

  FIG. 1 is a functional block diagram showing an overall configuration of an ultrasonic diagnostic apparatus suitable for implementing the present invention. The probe 10 is an ultrasonic probe provided with a plurality of vibration elements each transmitting and receiving ultrasonic waves. The ultrasonic diagnostic apparatus of FIG. 1 uses, for example, various probes 10 such as a convex scanning type, a sector scanning type, a linear scanning type, a two-dimensional image (tomographic image), and a three-dimensional image, depending on the diagnostic application. Can be used.

  The transmission beam former (transmission BF) 12 outputs a transmission signal to the plurality of vibration elements included in the probe 10 to control the plurality of vibration elements to form an ultrasonic transmission beam. Scan the transmit beam in the diagnostic region.

  When the transmission beam is scanned in the diagnostic region, each vibration element of the probe 10 receives an ultrasonic wave from the diagnostic region and outputs a received signal. A plurality of received signals obtained by the plurality of vibration elements are output to a diagnostic reception beamformer (diagnostic reception BF) 14 and an evaluation reception beamformer (evaluation reception BF) 16.

  The diagnostic receive beamformer 14 forms a diagnostic receive beam by, for example, phasing and adding a plurality of received signals obtained from a plurality of vibration elements, and line data (received signal) along the diagnostic receive beam. Get. In the phasing addition processing, a delay data set in which delay data that defines a delay amount for each vibration element is collected for a plurality of vibration elements is used.

  The delay data set is data determined based on the sound speed value in the living body. The ultrasonic diagnostic apparatus in FIG. 1 uses a plurality of delay data sets based on a plurality of different candidate sound speed values, and determines a delay data set based on an optimum sound speed value from the plurality of delay data sets. It has a function to do.

  The diagnostic receive beamformer 14 uses a delay data set based on the optimum sound velocity value, forms a diagnostic receive beam corresponding to the transmission beam scanned in the diagnostic area, and along the diagnostic receive beam, the diagnostic area Collect line data from within.

  The transmission beamformer 12 and the diagnostic reception beamformer 14 scan the ultrasonic beam (transmission beam and diagnostic reception beam corresponding thereto) to form a frame composed of a plurality of lines in the diagnostic region. Thus, a plurality of diagnostic frames are formed over a plurality of time phases in the diagnostic reception beamformer 14.

  The image forming unit 20 forms image data of an ultrasonic image based on line data (received signal) obtained one after another from the diagnostic receive beamformer 14. The image forming unit 20 forms image data of an ultrasound image related to a diagnostic region for each frame over a plurality of frames based on a plurality of line data constituting each frame. For example, the image forming unit 20 forms image data of a B-mode image (tomographic image). Note that the image forming unit 20 may form image data of an ultrasonic image such as a three-dimensional image or a Doppler image. An ultrasonic image corresponding to the image data formed in the image forming unit 20 is displayed on the display unit 22.

  The evaluation receive beamformer 16 forms an evaluation receive beam by, for example, phasing and adding a plurality of received signals obtained from the plurality of vibration elements included in the probe 10, and line data along the evaluation receive beam. (Received signal) is obtained. The reception beamformer for evaluation 16 uses a plurality of delay data sets corresponding to a plurality of candidate sound velocity values one after another, and forms an evaluation reception beam from the delay data sets based on each candidate sound velocity value.

  The evaluation reception beamformer 16 forms a plurality of evaluation frames over a plurality of time phases by forming an evaluation reception beam in accordance with the transmission beam scanned in the diagnostic region.

  The ROI setting unit 30 sets a region of interest (ROI) in each evaluation frame. Then, the evaluation selecting unit 40 selects an optimum sound speed value from among a plurality of candidate sound speed values based on line data (received signal) obtained along the evaluation reception beam from the region of interest.

  The control unit 50 centrally controls the inside of the ultrasonic diagnostic apparatus in FIG. In particular, the control unit 50 controls the diagnostic receive beamformer 14 so as to form a diagnostic receive beam using a delay data set based on the optimum sound speed value selected by the evaluation selecting unit 40. The control unit 50 may control the transmission beamformer 12 so as to form a transmission beam based on the optimum sound speed value selected by the evaluation selection unit 40.

  The transmission beamformer 12, the diagnostic reception beamformer 14, the evaluation reception beamformer 16, the image forming unit 20, the ROI setting unit 30, and the evaluation selection unit 40 each use hardware such as a processor or an electronic circuit, for example. Realized. Moreover, although the suitable specific example of the display part 22 is a liquid crystal display etc., it is not limited to this. The control unit 50 is configured by hardware such as a CPU having a calculation function, for example, and the function of the control unit 50 is realized by cooperation of the hardware and software (program) that defines the operation thereof. .

  Note that the ultrasonic diagnostic apparatus in FIG. 1 preferably includes an operation device including at least a part of, for example, a mouse, a trackball, a keyboard, a touch panel, and other switches.

  The overall configuration of the ultrasonic diagnostic apparatus in FIG. 1 is as described above. Next, functions and the like realized by the ultrasonic diagnostic apparatus of FIG. 1 will be described in detail. In addition, about the structure (part) shown in FIG. 1, the code | symbol of FIG. 1 is utilized in the following description.

  FIG. 2 is a diagram showing a specific example relating to selection of the optimum sound speed value. The diagnostic frame is a frame formed over a plurality of time phases in the diagnostic reception beamformer 14, and an ultrasonic image corresponding to the diagnostic frame is displayed on the display unit 22.

  On the other hand, the evaluation frame is a frame formed over a plurality of time phases in the evaluation reception beamformer 16 and is used in the ROI setting unit 30 and the evaluation selection unit 40 but is not displayed on the display unit 22. Note that an ultrasonic image corresponding to the evaluation frame may be displayed on the display unit 22 for the purpose of evaluation, for example.

  The evaluation frame is formed using a delay data set of candidate sound velocity values corresponding to each frame number over a plurality of frame numbers (a plurality of time phases).

  In the specific example shown in FIG. 2, the candidate sound speed values are 16 candidates of sound speed 1 to sound speed 16, and an evaluation frame of frame number F1 is formed using a delay data set based on sound speed 1, and the sound speed 2 An evaluation frame having the frame number F2 is formed using the delay data set based on the delay data set. Also in the frame numbers F4 to F15, the sound speed value is switched for each frame number, and the evaluation frame of the frame number F16 is formed using the delay data set based on the sound speed 16.

  Thereby, 16 evaluation frames of frame numbers F1 to F16 corresponding to 16 candidates of sound speed 1 to sound speed 16 are obtained. Note that evaluation frames corresponding to 16 candidates of sound speed 1 to sound speed 16 are repeatedly formed after frame number F17.

  When the evaluation frames corresponding to 16 candidates of sound speed 1 to sound speed 16 are formed, the evaluation selecting unit 40 selects from the sound speed 1 to sound speed 16 based on the line data (received signal) in each evaluation frame. The optimal sound speed value is selected. Note that the sound speeds 1 to 16 are, for example, values in the vicinity of 1530 m / s, which is a sound speed value generally used in an ultrasonic diagnostic apparatus, for example, a range of about 1520 m / s to about 1540 m / s. It is desirable to set in.

  The evaluation selection unit 40 uses, for example, the sum of signal intensities (total sum of line data sizes) in the region of interest (ROI) set in each frame for each evaluation frame. That is, for each evaluation frame corresponding to each of the sound velocities 1 to 16, the evaluation value is obtained by integrating the results of the phasing addition processing in the region of interest (ROI).

  If the delay data set based on the optimal sound speed value is used and the phasing addition process is performed properly, the phase of the multiple received signals obtained from the multiple transducer elements will be ideally aligned, Since the amplitude (size) of the line data obtained by the phasing addition processing is maximized, the evaluation value is also maximized. On the other hand, if the phasing addition process is performed using a delay data set based on a sound speed value other than the optimal sound speed value, the amplitude (magnitude) of the line data obtained by the phasing addition process is the optimal sound speed. Since the value is smaller than the value, the evaluation value is also small.

  Therefore, the evaluation selection unit 40 determines that the sound speed in the evaluation frame having the maximum evaluation value is optimal from the 16 evaluation frames corresponding to the sound speeds 1 to 16. Note that the sum of the signal intensities in the region of interest (ROI) is only one of the preferred specific examples as the evaluation value, and other known specific examples may be used as the evaluation value.

  When the optimum sound velocity value is selected, the diagnostic reception beamformer 14 is formed so as to form a diagnostic reception beam based on the delay data set based on the optimum sound velocity value from the diagnostic frame corresponding to the time phase immediately after that. Is controlled.

  In the specific example shown in FIG. 2, first, a diagnostic frame is formed using a delay data set based on the initial sound speed 1 in the period from frame numbers F1 to F16. In parallel with the formation of the diagnostic frame, an evaluation frame is formed using delay data sets corresponding to the sound speeds 1 to 16 as candidates in the period from frame numbers F1 to F16.

  When the evaluation frames having the frame numbers F1 to F16 are prepared, the evaluation selecting unit 40 selects the sound speed 3 as the optimum sound speed value from the sound speed 1 to the sound speed 16, and corresponds to the time phase immediately thereafter. A diagnostic frame having a frame number F17 is formed by a delay data set based on the sound speed 3 which is an optimum sound speed value.

  When the evaluation frames having the frame numbers F2 to F17 are prepared, the evaluation selection unit 40 selects the sound speed 2 as the optimum sound speed value from the sound speed 2 to the sound speed 16 and the sound speed 1, and the time phase immediately thereafter is selected. A diagnostic frame of frame number F18 corresponding to is formed by a delay data set based on the sound speed 2 that is the optimum sound speed value.

  Even after frame number F18, 16 evaluation frames to be evaluated are moved one frame at a time in the time axis direction, and the optimum sound speed is selected based on the latest 16 evaluation frames for each frame number. Is done.

  As described above, according to the ultrasonic diagnostic apparatus of FIG. 1, the evaluation reception beamformer 16 uses the delay data set based on the sound speed value for each sound speed value of the plurality of candidate sound speed values. Since the evaluation frame is formed to obtain the evaluation frame, it is not necessary for the inspector (user) to change the sound speed, and the burden on the user operation is reduced. In addition, since the optimum sound speed is selected based on the latest 16 evaluation frames for each time phase (each frame) in the evaluation selection unit 40, the diagnostic selection beamformer 14 forms the diagnostic frame. While displaying the corresponding ultrasonic image on the display unit 22, the ultrasonic image can be optimized in real time, for example.

  In selecting the optimum sound speed value, the ROI setting unit 30 sets a region of interest (ROI) in the evaluation frame. A plurality of regions of interest (ROI) may be set in the evaluation frame.

  FIG. 3 is a diagram illustrating a specific example of a plurality of regions of interest (ROI). FIG. 3A shows an example in which two regions of interest (ROI # L and ROI # R) are set side by side along the scanning direction in the evaluation frame. On the other hand, FIG. 3B shows an example in which two regions of interest (ROI # U and ROI # D) are set side by side along the depth direction in the evaluation frame. As already described, the evaluation selecting unit 40 uses, for example, the sum of signal intensities in the region of interest (ROI) as an evaluation value.

  In the example shown in FIG. 3A, the evaluation selection unit 40 obtains evaluation values for each of ROI # L and ROI # R for each evaluation frame, that is, for each sound velocity value. When evaluation values for a plurality of candidate sound velocity values are obtained from a plurality of evaluation frames, the evaluation selecting unit 40 selects an optimum sound velocity value for each of ROI # L and ROI # R. In the specific example shown in FIG. 3A, the sound speed L is selected as the optimal sound speed value of ROI # L, and the sound speed R is selected as the optimal sound speed value of ROI # R.

  When the optimum sound speed value is selected for each of ROI # L and ROI # R, the sound speed value in ROI # L and its vicinity is set to sound speed L, and the sound speed value in ROI # R and its vicinity is set to sound speed R. Then, a diagnostic frame is formed using a delay data set based on these optimum sound velocity values. For example, with reference to the boundary B set between ROI # L and ROI # R, the sound speed L is used in the region on the left side of the boundary B, and the sound speed R is used in the region on the right side of the boundary B.

  If the difference between the sound speed L and the sound speed R is large, streak-like artifacts may occur on the ultrasound image at the boundary B. Therefore, for example, when the difference between the sound speed L and the sound speed R is larger than the threshold value, a plurality of sound speed values are stepwise set between the sound speed L and the sound speed R from the ROI # L side to the ROI # R side. It may be changed.

  On the other hand, also in the example shown in FIG. 3B, the evaluation selection unit 40 obtains evaluation values for each of the ROI # U and ROI # D for each evaluation frame, that is, for each sound velocity value. When evaluation values for a plurality of candidate sound speed values are obtained from a plurality of evaluation frames, the evaluation selecting unit 40 selects an optimum sound speed value for each of ROI # U and ROI # D. In the specific example shown in FIG. 3B, the sound speed U is selected as the optimal sound speed value of ROI # U, and the sound speed D is selected as the optimal sound speed value of ROI # D.

  When the optimum sound speed value is selected for each of ROI # U and ROI # D, the sound speed value in ROI # U and its vicinity is set as sound speed U, and the sound speed value in ROI # D and its vicinity is set as sound speed D. Then, a diagnostic frame is formed using a delay data set based on these optimum sound velocity values. For example, with reference to the boundary B set between ROI # U and ROI # D, the sound velocity U is used in a region above (shallow side) the boundary B, and below (deep side) below the boundary B. The speed of sound D is used in the region.

  Similar to the case of FIG. 3A, also in the case of FIG. 3B, for example, when the difference between the sound speed U and the sound speed D is larger than the threshold value, the ROI # U side changes to the ROI # D side. On the other hand, a plurality of sound speed values may be changed stepwise between the sound speed U and the sound speed D.

  The ultrasonic diagnostic apparatus of FIG. 1 includes a delay data set for each reception beam for a plurality of reception beams constituting one frame, and further, a delay based on each candidate sound speed value for a plurality of candidate sound speed values. Has a data set. The delay data set is a data set with one reception beam as a unit, and the delay data set corresponding to one reception beam is formed based on the same candidate sound velocity value. Therefore, in order to use a plurality of candidate sound velocity values in accordance with the depth in one reception beam, a delay data set based on a combination of the plurality of candidate sound velocity values is required.

  For example, when two candidate sound speed values are used in the depth direction, the combination of two candidate sound speed values becomes a huge number of squares of the number of candidate sound speed values (for example, 16). Therefore, the ultrasonic diagnostic apparatus of FIG. 1 determines an optimal combination of sound speed values in two regions of interest set in the depth direction by a relatively simple process described below.

  FIG. 4 is a diagram illustrating a specific example of processing related to selection of optimum sound speed values in two regions of interest set in the depth direction. FIG. 4 shows a specific example of processing for selecting the optimum sound speed value for each of the two regions of interest ROI # U and ROI # D in FIG. In the specific example shown in FIG. 4, the evaluation target is switched to ROI # U and ROI # D.

  FIG. 4A shows a setting example of candidate sound speed values when ROI # U is an evaluation target. When ROI # U is an evaluation target, the sound speed value in ROI # U is changed for each frame while the sound speed value in ROI # D is fixed. For example, as shown in FIG. 4A, for ROI # U, the sound speed value is changed from sound speed 1 to sound speed 16 for each frame (each time phase) along the time axis direction, and the sound speed at ROI # D is changed. The value is fixed at the sound speed D, and for each frame, an evaluation value in the ROI #U is obtained by a delay data set based on the combination of the sound speed value in the ROI #U and the sound speed value in the ROI #D. The sound speed value of ROI # U when the evaluation value is maximized is set to the optimum sound speed value in ROI # U.

  On the other hand, FIG. 4B shows a setting example of the candidate sound speed value when ROI # D is an evaluation target. When ROI # D is an evaluation target, the sound speed value in ROI # D is changed for each frame while the sound speed value in ROI # U is fixed. For example, as shown in FIG. 4 (2), for ROI # D, the sound speed value is changed from sound speed 1 to sound speed 16 for each frame (each time phase) along the time axis direction, and the sound speed at ROI # U is changed. The value is fixed at the sound speed U, and for each frame, an evaluation value in ROI #D is obtained by a delay data set based on a combination of the sound speed value in ROI #U and the sound speed value in ROI #D. The sound speed value of ROI # D when the evaluation value is maximized is set to the optimum sound speed value in ROI # D.

  FIG. 4 (3) shows a specific example in which the optimum sound speed value is selected while switching the evaluation target. First, in period 1, the evaluation target is ROI # U, and the optimum sound speed value in ROI # U is selected by the processing described with reference to FIG. In period 1, the sound speed value at ROI # D is fixed to the initial sound speed D1, for example.

  Next, in period 2, the evaluation target is ROI # D, and the optimum sound speed value in ROI # D is selected by the processing described with reference to FIG. In period 2, the sound speed value in ROI # U is fixed to, for example, the sound speed U1 that is the optimum sound speed value selected in period 1.

  Further, in period 3, the evaluation target is ROI # U, and the optimum sound speed value in ROI # U is selected by the process described with reference to FIG. In period 3, the sound speed value in ROI # D is fixed to, for example, the sound speed D2 that is the optimum sound speed value selected in period 2.

  Thus, in period 4 and thereafter, the optimum sound speed value is alternately selected for ROI # U and ROI # D while switching the evaluation target. Note that the period 1 to the period 4 and the subsequent periods are, for example, about 100 ms.

  According to the processing described with reference to FIG. 4, it is possible to determine the optimum combination of sound speed values of the two regions of interest ROI # U and ROI # D set in the depth direction by relatively simple processing. it can.

  As mentioned above, although preferred embodiment of this invention was described, embodiment mentioned above is only a mere illustration in all the points, and does not limit the scope of the present invention. The present invention includes various modifications without departing from the essence thereof.

  10 probe, 12 transmit beamformer, 14 diagnostic receive beamformer, 16 receive beamformer for evaluation, 20 image forming unit, 22 display unit, 30 ROI setting unit, 40 evaluation selection unit, 50 control unit.

Claims (5)

A probe for transmitting and receiving ultrasound,
A diagnostic beam forming unit for forming an ultrasonic diagnostic beam based on a received signal obtained from a probe;
An image forming unit that forms an ultrasound image based on a received signal obtained along the diagnostic beam;
Based on the received signal, for each sound speed value of a plurality of sound speed values, an evaluation beam forming unit that forms an ultrasonic evaluation beam by a beam forming process based on the sound speed value;
An evaluation selection unit that selects an appropriate sound speed value from the plurality of sound speed values based on a received signal obtained along the evaluation beam;
A control unit that controls the diagnostic beam forming unit so as to form a diagnostic beam by a beam forming process based on the appropriate acoustic velocity value from a time phase after the appropriate acoustic velocity value is selected;
Having
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 1,
The diagnostic beam forming unit forms a plurality of diagnostic frames over a plurality of time phases by scanning the diagnostic beam,
The evaluation beam forming unit scans the evaluation beam to form a plurality of evaluation frames each corresponding to a time phase of each diagnostic frame,
The evaluation selection unit selects an appropriate sound speed value based on a received signal obtained over a plurality of evaluation frames,
The control unit controls the diagnostic beam forming unit to form a diagnostic beam from a diagnostic frame corresponding to a time phase immediately after the appropriate sound speed value is selected by beam forming processing based on the appropriate sound speed value. ,
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 2,
The evaluation beam forming unit forms an evaluation beam for each evaluation frame by a beam forming process based on a sound velocity value corresponding to the evaluation frame,
The evaluation selection unit selects an appropriate sound speed value based on an evaluation value obtained from a plurality of evaluation frames corresponding to the plurality of sound speed values;
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 2 or 3,
A region-of-interest setting unit for setting one or a plurality of regions of interest in each evaluation frame;
The evaluation selection unit selects an appropriate sound velocity value in the region of interest for each region of interest.
An ultrasonic diagnostic apparatus. In the ultrasonic diagnostic apparatus according to any one of claims 1 to 4,
The probe includes a plurality of vibration elements each transmitting and receiving ultrasonic waves,
The evaluation beam forming unit uses a delay data set composed of delay data related to each of a plurality of vibration elements, forms an evaluation beam using a delay data set based on each sound velocity value,
The evaluation selection unit selects an appropriate sound speed value from the plurality of sound speed values based on a reception signal obtained along the evaluation beam,
The diagnostic beam forming unit forms a diagnostic beam from a time phase after the appropriate sound velocity value is selected using a delay data set based on the appropriate sound velocity value.
An ultrasonic diagnostic apparatus.

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