Method and apparatus for obtaining elastic feature of object

An ultrasound apparatus comprising:

• a shear wave inducer configured to induce a first shear wave in an object by transmitting a first push ultrasound signal which is generated by a probe of the ultrasound apparatus and a first grating lobe signal which relates to the first push ultrasound signal toward the object;
• a shear wave detector configured to transmit a first tracking ultrasound signal to an area of the object where the first shear wave has propagated and to receive a first reflection signal which relates to the first tracking ultrasound signal from the object;
• and
• a controller configured to measure a first shear wave parameter which indicates a shear wave characteristic of the first shear wave based on the received first reflection signal and to obtain an elastic feature of the object by using the measured first shear wave parameter,
• wherein the first push ultrasound signal induces a first sub-shear wave propagating in a first direction and the first grating lobe signal induces a second sub-shear wave propagating in a second direction different from the first direction, and
• wherein the first shear wave is a synthesis of the first sub-shear wave and the second sub-shear wave.