Provided is an ultrasound diagnostic device having an elasticity evaluation function with which high accuracy and high reproducibility can be achieved while avoiding the influence of internal stresses. The ultrasound diagnostic device comprises: a transceiver which causes a probe for transmitting and receiving ultrasonic waves to transmit and receive first, second, third ultrasonic waves to and from a subject; an image production unit for producing an image on the basis of a received signal related to the first ultrasonic wave; a velocity measurement unit which sets a measurement region on the basis of the produced image, transmits the second ultrasonic wave to the measurement region to create shear waves, and calculates the propagation velocity of the shear waves from a received signal obtained by transmitting and receiving the third ultrasonic wave to and from the measurement region; and an elasticity evaluation unit for evaluating the elasticity of the subject on the basis of the calculated propagation velocity. The velocity measurement unit measures the propagation velocity at the same position a plurality of times. The elasticity evaluation unit derives an elasticity evaluation index using variations in the results obtained by measuring the propagation velocity a plurality of times.

An ultrasound diagnosis apparatus includes a transmitting and receiving circuitry, an input circuitry, and a processing circuitry. The transmitting and receiving circuitry transmits a first ultrasound wave used for changing the shape of a tissue in the body of a patient and transmits/receives a second ultrasound wave that is transmitted/received with timing different from that of the first ultrasound wave. The input circuitry receives an input of a request indicating that the first ultrasound wave should be transmitted. When the input circuitry has received the input of the request indicating that the first ultrasound wave should be transmitted, the processing circuitry controls the transmission of the first ultrasound wave in accordance with the strength of a reflected-wave signal of the second ultrasound wave or one or more pixel values of an image resulting from an imaging process performed by using the reflected-wave signal of the second ultrasound wave.

For noise reduction in elasticity imaging, frequency compounding is used. Displacements caused by the acoustic radiation force impulse are measured using signals at different frequencies, either due to transmission of tracking pulses and reception at different frequencies or due to processing received signals at different sub-bands. The displacements are (a) combined to compound and the compounded displacements are used to determine elasticity or (b) are used to determine elasticity and the elasticities from information at the different frequencies are compounded.

In viscoelastic imaging with ultrasound, the shear wave speed or other viscoelastic parameter is measured by tracking at the ARFI focal or other high-intensity location relative to the ARFI transmission. Rather than tracking the shear wave, the tissue response to ARFI is measured. A profile of displacements over time or a spectrum thereof is measured at the location. By finding a scale of the profile resulting in sufficient correlation with a calibration profile, the shear wave speed or other viscoelastic parameter may be estimated.

Circuitry for ultrasound devices is described. A multilevel pulser is described, which can provide bipolar pulses of multiple levels. The multilevel pulser includes a pulsing circuit and pulser and feedback circuit. Symmetric switches are also described. The symmetric switches can be positioned as inputs to ultrasound receiving circuitry to block signals from the receiving circuitry.

Ultrasound-based acoustic streaming for deciding whether material is fluid is dependent upon any one or more of a variety of criteria. Examples are displacement, speed (230), temporal or spatial flow variance, progressive decorrelation, slope or straightness of accumulated signal to background comparisons over time, and relative displacement to adjacent soft tissue. Echogenicity-based area identification is combinable with the above movement characteristic detection in the deciding. Fluid pool identification is performable from the area-limited acoustic streaming testing and ultrasound attenuation readings. Candidates from among the areas (210) are screenable based on specific shapes or bodily organs detected. Natural flow can be excluded from streaming detection by identification of blood vessels (206). Processing for each FAST ultrasound view (202), or for the entire procedure, is performable automatically, without need for user intervention or with user intervention to identify suspected areas.

According to the present invention, a displacement measurement unit measures, on the basis of a reception signal corresponding to a tracking wave reception beam obtained from a reception unit, the displacement of a tissue inside a subject after the generation of a shear wave. A fluctuation detection unit detects periodic displacement on the basis of the displacement measurement result obtained from the displacement measurement unit. A shear wave speed calculation unit calculates the propagation speed of a shear wave in the subject on the basis of the measurement result obtained from the displacement measurement unit and the detection result obtained from the fluctuation detection unit.

Shear wave propagation is used to estimate the speed of sound in a patient. An ultrasound scanner detects a time of occurrence of a shear wave at each of multiple locations. The difference in time of occurrence, given tissue stiffness or shear velocity, is used to estimate the speed of sound for the specific tissue of the patient.

A method for performing shear wave elastography imaging of an observation field in a medium, the method including shear wave imaging steps to acquire sets of shear wave propagation parameters, the method further including a reliability indicator determining step during which a reliability indicator of the shear wave elastography imaging of the observation field is determined.

A method for quantitatively measuring a physical characteristic of a material includes performing one or more interrogations of a material sample, each interrogation using a push focal configuration. The method further includes taking measurements of displacement over time of a material sample caused by the one or more interrogations. Each measurement uses an interrogation focal configuration. The method further includes determining a physical characteristic of the material sample based on the measurements of displacement over time of the material sample. According to the method, at least one of the following is true: a tracking focal configuration used for one of the measurements is different from a tracking focal configuration used for another of the measurements; and a push focal configuration used for one of the interrogations is different from a push focal configuration used for another of the interrogations.