G01S7/52022

IMAGING METHODS AND APPARATUSES FOR PERFORMING SHEAR WAVE ELASTOGRAPHY IMAGING

A method for performing shear wave elastography imaging of an observation field in a medium includes shear wave imaging operations to acquire sets of shear wave propagation parameters, and determining a reliability indicator of the shear wave elastography imaging of the observation field.

Multilevel bipolar pulser

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.

HARMONIC SHEAR WAVE IMAGING

A method of performing shear wave elastography in tissue includes transmitting successively a series of ultrasound push pulses in the tissue in a region of interest (ROI) using a single array transducer. The acoustic intensities of the push pulses are sinusoidally modulated with a modulation frequency, Each push pulse generates an acoustic radiation force that pushes the tissue and creates an individual shear wave propagating through the tissue. The amplitudes of the shear waves, and therefore, the displacements produced by the push pulses, are positively proportionally to the intensities of the push pulses. The successively created individual shear waves with different amplitudes sum together to form a continuous, harmonic summed shear wave with a single frequency the same as the modulation frequency of the push pulses.

MULTI-PARAMETRIC TISSUE STIFFNESS QUANATIFICATION

The present disclosure describes ultrasound systems and methods configured to determine stiffness levels of anisotropic tissue. Systems can include an ultrasound transducer configured to acquire echoes responsive to ultrasound pulses transmitted toward anisotropic tissue having an angular orientation with respect to a nominal axial direction of the transducer. Systems can also include a beamformer configured to control the transducer to transmit a push pulse along a steering angle for generating a shear wave in the anisotropic tissue. The steering angle can be based on the angular orientation of the tissue. The transducer can also be controlled to transmit tracking pulses. Systems can also include a processor configured to store tracking line echo data generated from echo signals received at the transducer. In response to the echo data, the processor can detect motion within the tissue caused by propagation of the shear wave and measure the velocity of the shear wave.

Diffraction correction for attenuation estimation in medical diagnostic ultrasound

For estimating attenuation, diffraction effects are corrected by transmitting at different frequencies using apertures sized to match the on-axis intensity profile and/or resolution cell size between the transmissions where there is no attenuation. Attenuation causes a variance in return. A rate of change is estimated from a ratio of the magnitude of the signals or displacements responsive to the transmissions. The attenuation is calculated from the rate of change over depth of the ratio.

System and Method for Shear Wave Elastography by Transmitting Ultrasound with Subgroups of Ultrasound Transducer Elements

Systems and methods for performing shear wave elastography using push and/or detection ultrasound beams that are generated by subsets of the available number of transducer elements in an ultrasound transducer. These techniques provide several advantages over currently available approaches to shear wave elastography, including the ability to use a standard, low frame rate ultrasound imaging system and the ability to measure shear wave speed throughout the entire field-of-view rather than only those regions where the push beams are not generated.

SHEAR WAVE ELASTROGRAPHY METHOD AND APPARATUS FOR IMAGING AN ANISOTROPIC MEDIUM
20210338206 · 2021-11-04 ·

A shear wave elastography method for imaging an observation field in an anisotropic medium, including an initial ultrasonic acquisition step during which initial physical parameters are acquired in at least one region of interest; a spatial characterization step during which a set of spatial characteristics of the anisotropic medium is determined on the basis of the initial physical parameter; an excitation substep during which an shear wave is generated inside the anisotropic medium on the basis of the set of spatial characteristics; and an observation substep during which the propagation of the shear wave is observed simultaneously at a multitude of points in the observation field.

ULTRASONIC SHEARWAVE IMAGING WITH PATIENT-ADAPTIVE SHEARWAVE GENERATION
20220386996 · 2022-12-08 ·

An ultrasonic diagnostic imaging system acquires different kinds of pilot images showing different characteristics of a region of a body where shearwave measurements are performed. The pilot images are analyzed by a push pulse locator to adaptively generate push pulses at locations in the body which minimize or avoid shearwave travel through blood vessels, through regions of stiffness inhomogeneities in the body, or at times when shearwaves are adversely affected by tissue motion.

ADAPTIVE CLUTTER FILTERING IN ACOUSTIC RADIATION FORCE-BASED ULTRASOUND IMAGING
20230012638 · 2023-01-19 ·

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.

Damage Detection Using Two-Stage Compressive Sensing

Described herein are Compressive Sensing algorithms developed for automated reduction of NDE/SHM data from pitch-catch ultrasonic guided waves as well as a methodology using Compressive Sensing at two stages in the data acquisition and analysis process to detect damage: (1) temporally undersampled sensor signals from (2) spatially undersampled sensor arrays, resulting in faster data acquisition and reduced data sets without any loss in damage detection ability.