Ultrasound diagnostic device and ultrasound diagnostic device control method

An ultrasound diagnostic device that causes a probe to transmit a push wave focused on a specific site in a subject and detects propagation speed of a shear wave generated by acoustic radiation force of the push wave, the probe being connectable to the ultrasound diagnostic device and including transducers arranged in a row, the ultrasound diagnostic device comprising:

• ultrasound signal processing circuitry, the ultrasound signal processing circuitry comprising:
• a push wave pulse transmitter that supplies a push wave pulse to a plurality of the transducers that causes the plurality of the transducers to transmit the push wave;
• a detection wave pulse transmitter that, a plurality of times after the push wave pulse, supplies a detection wave pulse to a plurality of the transducers that causes the plurality of the transducers to transmit a detection wave that passes through a region of interest that represents a range to be analyzed in the subject;
• a detection wave receiver that generates acoustic line signals with respect to observation points in the region of interest, based on reflected detection waves that correspond to the detection waves and are reflected from subject tissue and received in a time sequence by a plurality of the transducers, and generates a sequence of acoustic line signal frame data;
• a displacement detector that, from the sequence of acoustic line signal frame data, detects displacement of tissue in the region of interest for each receive time of the reflected detection waves, and generates a sequence of displacement frame data;
• a propagation information analyzer that extracts shear wave wavefront position from the sequence of the displacement frame data, generates a sequence of wavefront frame data, and generates wavefront arrival time frame data by associating wavefront position included in each frame of the wavefront frame data with the receive time;
• a propagation information estimator that evaluates reliability of wavefront arrival time data in the wavefront arrival time frame data and, for reliability nonconformance wavefront arrival time data in the wavefront arrival time frame data that does not satisfy a predefined condition, generates compensated wavefront arrival time data by interpolation based on wavefront arrival time data that does satisfy the predefined condition, replaces the reliability nonconformance wavefront arrival time data with the compensated wavefront arrival time data, and generates compensated wavefront arrival time frame data;
• and
• an elastic modulus calculator that calculates shear wave propagation speed and/or elastic modulus frame data in the region of interest, based on the compensated wavefront arrival time frame data.