Abstract: 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.

Abstract: High volume-rate three-dimensional (“3D”) ultrasound imaging using fast acoustic steering via tilting electromechanical reflectors is described. Ultrasound beams are directed towards one or more tilting reflectors, which are scanned through a range of tilt angles in order to image a 3D field-of-view with a high volume rate.

Abstract: Systems and methods for removing the bias induced by noise from power Doppler images to achieve improvements of microvessel image contrast are provided. In one example, the noise-induced bias can be suppressed by utilizing the characteristics of uncorrelated noise in the ultrasound image from data acquired or compounded at different transmitting angles. In another example, the noise-induced bias can be suppressed due to the lack of correlation between adjacent ultrasound images. These example implementations may also be combined, as will be described below.

Abstract: 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.

Abstract: A main power load signal and a main voltage reference signal correlated to a main power signal. A sub power load signal and a sub voltage reference signal correlated to a sub power signal. A reference voltage is provided and a boost voltage is determined according to a control signal. The main voltage reference signal and the sub voltage reference signal are compared, and when the first comparison result complies with a predetermined condition, a difference between the main voltage reference signal and the sub voltage reference signal is obtained to be further compared with the reference voltage. Then the control signal is determined. The main power load signal and the sub power load signal are compared, and then one of the sub voltage reference signal and the boost voltage is selected as a power source voltage of the sub power control circuit or the load sharing control circuit to generate an adjustment signal for determining current and voltage of the sub power signal.

Abstract: Methods for contrast-enhanced ultrasound imaging that implement coded multi-pulses in each of two or more different transmission events are described. Data acquired in response to the two different transmission events are decoded and combined. In some embodiments, the coded multi-pulses include two or more consecutive Hadamard encoded ultrasound pulses. In other embodiments, multiplane wave pulses can be used. Such multiplane wave pulses can be coded using Hadamard encoding, as one example. In addition, the multiplane wave pulses can be further coded using amplitude modulation, pulse inversion, or pulse inversion amplitude modulation techniques.

Abstract: A main power load signal and a main voltage reference signal correlated to a main power signal. A sub power load signal and a sub voltage reference signal correlated to a sub power signal. A reference voltage is provided and a boost voltage is determined according to a control signal. The main voltage reference signal and the sub voltage reference signal are compared, and when the first comparison result complies with a predetermined condition, a difference between the main voltage reference signal and the sub voltage reference signal is obtained to be further compared with the reference voltage. Then the control signal is determined. The main power load signal and the sub power load signal are compared, and then one of the sub voltage reference signal and the boost voltage is selected as a power source voltage of the sub power control circuit or the load sharing control circuit to generate an adjustment signal for determining current and voltage of the sub power signal.

Abstract: A method for imaging an object by ultrasound elastography through continuous vibration of the ultrasound transducer is taught. An actuator directly in contact with the ultrasound transducer continuously vibrates the transducer in an axial direction, inducing shear waves in the tissue and allowing for real-time shear wave imaging. Axial motion of the transducer contaminates the shear wave images of the tissue, and must be suppressed. Therefore, several methods for correcting for shear wave artifact caused by the motion of the transducer are additionally taught.

Abstract: Systems and methods for harmonic shear wave detection using low frame rate ultrasound, or a three-dimensional (3D) volumetric scan, are provided. As one example, spurious motion sources, such as intrinsic tissue motion and waves that are not at the incident wave harmonic frequency, are removed based on a scanning sequence in which repeated acquisitions from a given subvolume occur closely in time so as to render effects of the spurious motions negligible. As another example, sampling frequency and center frequency are selected such that the spurious motion signal spectra do not overlap with aliased shear wave motion spectra, such that the spurious motions can be filtered.

Abstract: Systems and methods for super-resolution ultrasound imaging of microvessels in a subject are described. Ultrasound data are acquired from a region-of-interest in a subject who has been administered a microbubble contrast agent. The ultrasound data are acquired while the microbubbles are moving through, or otherwise present in, the region-of-interest. The region-of-interest may include, for instance, microvessels or other microvascuiature in the subject. By isolating, localizing, tracking, and accumulating the microbubbles in the ultrasound data, super-resolution images of the microvessels can be generated.

Abstract: Systems and methods for ultrasound imaging using a delay-encoded harmonic imaging (“DE-HI”) technique is provided. An ultrasound pulse sequence is coded using temporal delays between ultrasound emissions within a single transmission event. This coded scheme allows for harmonic imaging to be implemented. The temporal time delay-codes are applied temporally to multiple different ultrasound emissions within a single transmission event, rather than spatially across different transmitting elements. The received radio frequency (“RF”) signals undergo a decoding process in the frequency domain to recover the signals, as they would be obtained from standard single emissions, for subsequent compounding. As one specific example, a one-quarter period time delay can be used to encode second harmonic signals from each angle emission during a single multiplane wave (“MW”) transmission event, rather than inverting the polarity of the pulses as in conventional MW imaging.

Abstract: Systems and methods for estimating acoustic properties in a region-of-interest in a subject or other object being imaged using a reference frequency method (“RFM”) is described. Using this RFM technique, ultrasound data acquired at a given frequency are normalized by ultrasound data acquired at different frequencies (e.g., adjacent frequencies or otherwise) in order to provide estimations of the acoustic properties (e.g., attenuation coefficient, a backscatter coefficient, or both) that are independent of the ultrasound system used to acquire the underlying data. For instance, the amplitude of each frequency component can be normalized by a different frequency in the power spectrum to cancel out the system-dependent effects. Because the methods described in the present disclosure are system independent, they can be applied to any transducer geometry (e.g., linear or curved arrays) and using any beam pattern (e.g., focused or unfocused).

Abstract: 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.

Abstract: Systems and methods for ultrafast synthetic transmit aperture (“USTA”) ultrasound imaging using coded virtual sources are described. The methods can implement spatially distinct or spatially overlapping sub-apertures with appropriate timing of transmission between the spatially overlapping sub -apertures. The systems and methods described here are capable of increasing signal-to-noise ratio (“SNR”) and spatial resolution to reduce frame rate.

Abstract: Described here are systems and methods for imaging blood flow in a subject's vasculature, which may include small blood vessels, using ultrasound without the need for a contrast agent. A locally implemented low-rank matrix decomposition is used together with adaptive cutoff values to provide noninvasive ultrasound blood flow imaging capable of imaging the subject's vasculature with very high spatial and temporal resolution, and without the administration of contrast agents such as microbubble contrast agents. Thus, in some instances the systems and methods can be used to image blood flow in small vessels and tissue microvasculature with high spatial and temporal resolution.

Abstract: 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.

Abstract: Systems and methods for processing data acquired using ultrasound elastography, in which shear waves are generated in a subject using continuous vibration of an ultrasound transducer, are provided. The systems and methods described here can effectively remove motion artifacts associated with vibration of the ultrasound transducer, and can also remove the data sampling misalignment caused when a line-by-line imaging mode is used to acquire data, as is done by many conventional ultrasound scanners. Thus, the systems and methods described here provide techniques for transducer motion correction and for aligning motion signals detected by line-by-line scanning ultrasound systems.

Abstract: Described here are systems and methods for ultrasound clutter filtering to produce images of blood flow in a subject. In general, the clutter filtering is based on a singular value implementation, such as an accelerated singular value decomposition (“SVD”). In one example, the singular value-based clutter filtering can be accelerated by implementing a randomized SVD (“rSVD”). In another example, the singular value-based clutter filtering can be accelerated by implementing a randomized spatial downsampling. In still another example, singular value-based clutter filtering can be accelerated by implementing both an rSVD and a randomized spatial downsampling.

Abstract: A system and method for performing a steered push beam (SPB) technique to create multiple foci generated by the interference of different ultrasound push beams to create shear waves and, based thereon, generate a report indicating mechanical properties about an object.

Abstract: A method for imaging an object by ultrasound elastography through continuous vibration of the ultrasound transducer is taught. An actuator directly in contact with the ultrasound transducer continuously vibrates the transducer in an axial direction, inducing shear waves in the tissue and allowing for real-time shear wave imaging. Axial motion of the transducer contaminates the shear wave images of the tissue, and must be suppressed. Therefore, several methods for correcting for shear wave artifact caused by the motion of the transducer are additionally taught.