An ultrasonic diagnosis apparatus according to an embodiment includes a transmission unit, a reception unit, a generator, and a display controller. The transmission unit causes an ultrasonic probe to transmit a displacement-producing ultrasonic wave and causes the probe to transmit a displacement-observing ultrasonic wave. The reception unit generates reflected-wave data based on a reflected wave received by the probe. The generator calculates displacement at each of a plurality of positions in the scan area over a plurality of time phases, based on the reflected-wave data, determines a time phase when the calculated displacement is substantially maximum, for each of the positions, and generates image data representing positions where the determined time phases are substantially the same as each other, among the positions. The display controller superimposes an image based on the image data on a medical image corresponding to an area including the scan area.

Disclosed are an ultrasonic viscoelasticity measuring method, an apparatus and a storage medium. The method comprises: outputting a first transmitting/receiving sequence to a transducer of an ultrasonic probe to control the transducer to transmit a first ultrasonic wave to a target object and acquire a first ultrasonic echo signal; generating and displaying an ultrasonic image based on the first ultrasonic echo signal and acquiring a region of interest on the ultrasonic image; outputting different drive signals to a vibrator of the ultrasonic probe to perform viscoelasticity measurement, and exerting various mechanical vibrations on the target object by the transducer driven by the vibrator based on at least two different vibration signals; outputting a second transmitting/receiving sequence to the transducer to control the transducer to transmit a second ultrasonic wave to the region of interest to acquire a second ultrasonic echo signal; and acquiring and displaying elasticity parameter(s) and viscosity parameter(s) of the region of interest based on the second ultrasonic echo signal of the region of interest under the various mechanical vibrations. The proposed scheme can effectively improve the accuracy and stability of measured result.

System and method for shear wave elasticity imaging perform a) acquiring B-mode ultrasound images of a target region; b) selecting a region of interest; c) transmitting a shear wave excitation pulse; d) measuring displacements of tracking focal points or depth ranges at different depths positions along each of laterally staggered tracking lines within the selected region of interest; e) determining a curve representing displacement of tissue as a function of time at different spatial locations within the region of interest; f) determining for spatial locations candidate time(s) of arrival of the shear wave at the spatial location as a function of the curve; g) finding linear functional relation between the time of arrival and the spatial coordinate in the lateral direction using Random Sample Consensus (RANSAC) algorithm; and h) determining the inverse of velocity of the shear wave in a spatial location as the angular coefficient of the linear function.

A method for performing shear wave elastography imaging of an observation field in a medium, the method comprising a plurality of shear wave imaging steps (30) to acquire a plurality of sets of shear wave propagation parameters, the method further comprising a reliability indicator determining step (40) during which a reliability indicator of the shear wave elastography imaging of the observation field is determined.

A method for two-dimensional sheare wave elastography imaging comprises: a) acquiring B-mode ultrasound images of a target region in a body; b) selecting a region of interest inside the B-mode image; c) transmitting a shear wave excitation pulse focalized on an excitation region; d) measuring displacements of tracking focal points at different depths positions along laterally staggered tracking lines within the region of interest; e) determining elasticity parameters of the regions between two of the tracking focal points at the same depth and on at least two adjacent tracking lines as a function of the displacements caused by the shear wave at the tracking focal points; f) modifying the appearance of pixel(s) of the B-mode image inside the regions relatively to the grey-scale B-mode image as a function of elasticity parameters determined for the regions; and g) displaying the pixel(s) having a modified appearance at the corresponding pixel of the B-mode image.

A transducer array includes at least one annular shear wave generation transducer that defines an interior area, the at least one annular shear wave generation transducer being configured to generate a shear wave excitation to a region of interest such that the shear wave excitation excites at least a part of a corresponding cylindrical portion of the region of interest and shear waves propagating from the cylindrical portion of the region of interest constructively interfere in an interior region of the cylindrical portion of the region of interest; and at least one tracking transducer positioned in the interior area of the at least one annular shear wave generation transducer, the at least one tracking transducer being configured to detect a shear wave in the interior region of the region of interest.

An ultrasonic diagnostic imaging system produces an image of shear wave velocities by transmitting push pulses to generate shear waves. A plurality of tracking lines are transmitted and echoes received by a focusing beamformer adjacent to the location of the push pulses. The tracking lines are sampled in a time-interleaved manner. The echo data acquired along each tracking line is processed to determine the time of peak tissue displacement caused by the shear waves at points along the tracking line, and the times of peaks at adjacent tracking lines compared to compute a local shear wave velocity. The resultant map of shear wave velocity values is color-coded and displayed over an anatomical image of the region of interest.

For clutter reduction in ultrasound elasticity imaging, the contribution of clutter to different frequency components (e.g., the transmit fundamental and the propagation generated second harmonic) is different. As a result, a difference in displacements determined at the different frequency bands is used to reduce clutter contribution to displacements used for elasticity imaging.

The present disclosure describes ultrasound systems and methods configured to interrogate the stiffness and/or elasticity of a target tissue via shear wave imaging Systems may be configured to stroboscopically transmit a plurality of push pulses into the target tissue at different focal depths. The quickly transmitted push pulses may generate shear waves that constructively interfere to form a composite shear wave. Example systems may include a beamformer configured to transmit push pulse parameters to a transducer array while receiving new push pulse parameters from a controller. Dual transmission and receipt of different push pulse parameters reconfigures the beamformer without interrupting push pulse transmission, thereby minimizing the delay between successive push pulses. Push pulses transmitted according to the disclosed methods may generate a composite shear wave configured to interrogate tissue with enhanced sensitivity across a broad depth.

Methods and apparatus measuring tissue nonlinear shear wave property are disclosed. When tissue shear responses are different to ultrasound radiation forces generated by pulses having different shapes, its nonlinear effect can be used to estimate tissue property at single location without measurements of group velocities or phase velocities. Ultrasound radiation force using a single tone burst pulse is applied to a selected location in a tissue region. The induced shear wave is detected in the region and its spectral distribution is calculated and analyzed. This detection may be repeated with other excitation pulses having different widths or different shapes at the same location. The spectral analysis of the detected shear wave is performed according to a nonlinear shear model for solving nonlinearity and viscoelasticity of the tissue at a single location in a tissue region. The detection location can be at one point at a time for imaging two-dimensional or three-dimensional tissue nonlinearities and shear wave properties. The property includes nonlinear magnitude variations, nonlinear phase variations, nonlinear coefficients, and viscoelasticity. The induced shear wave are detected at multiple locations along the shear propagation directions in the tissue region for calculating different shear group velocities and different shear phase velocities using different excitation pulses, and calculating nonlinearity and viscoelasticity. A difference between certain aspects of this disclosure and the prior art of ultrasound elastography is the utilization of nonlinear responses of the tissue shear property.