Techniques, systems, and devices are disclosed for synthetic aperture ultrasound imaging using spread-spectrum, wide instantaneous band, coherent, coded waveforms. In one aspect, a method includes synthesizing a composite waveform formed of a plurality of individual orthogonal coded waveforms that are mutually orthogonal to each other, correspond to different frequency bands and including a unique frequency with a corresponding phase; transmitting an acoustic wave based on the composite waveform toward a target from one or more transmitting positions; and receiving at one or more receiving positions acoustic energy returned from at least part of the target corresponding to the transmitted acoustic waveforms, in which the transmitting and receiving positions each include one or both of spatial positions of an array of transducer elements relative to the target and beam phase center positions of the array, and the transmitted acoustic waveforms and the returned acoustic waveforms produce an enlarged effective aperture.

A multiple aperture ultrasound imaging system may be configured to store raw, un-beamformed echo data. Stored echo data may be retrieved and re-beamformed using modified parameters in order to enhance the image or to reveal information that was not visible or not discernible in an original image. Raw echo data may also be transmitted over a network and beamformed by a remote device that is not physically proximate to the probe performing imaging. Such systems may allow physicians or other practitioners to manipulate echo data as though they were imaging the patient directly, even without the patient being present. Many unique diagnostic opportunities are made possible by such systems and methods.

Disclosed is a high resolution intravascular ultrasound imaging system including a catheter with a rotatable imaging assembly and an image processor. The image processor in turn features a pulser configured to energize the ultrasound transducer of the rotatable imaging assembly with a multi-frequency ultrasound waveform signal. The image processor further contains a receiver configured to decompose received ultrasound energy as reflected by the target vessel into a plurality of individual subband signals, individually process these signals and reconstitute these signals into a high resolution image of the blood vessel. The IVUS system of the invention may be useful in characterizing cap thickness of vulnerable plaques or other detailed studies of blood vessels.

Fresnel elevation focusing at a selected elevation angle is performed by transmitting a sequential set of Fresnel-focused ultrasound pulses, where a different Fresnel phase pattern is used for each pulse, and where the receive signals are coherently compounded. The different Fresnel patterns cause the secondary lobe energy to be reduced via averaging of variations of the pressure fields in the secondary lobe regions. In some embodiments, the method of coherently compounded Fresnel focusing is combined with coherently compounded defocused wave (e.g. plane wave or diverging wave) imaging in the azimuth direction. Each of the elevation slices are collected by changing the Fresnel patterns respectively employed when the sequence of plane waves or diverging waves are transmitted, such that the coherent compounding can benefit both planes simultaneously. Hadamard receive encoding and subsequent dynamic receive beamforming may be employed to further improve performance in the elevation direction.

According to the invention, n incident acoustic waves Ei(t), obtained by linearly combining n elemental incident waves E0i(t) with an encoding matrix Hc are consecutively transmitted in a medium to be imaged. n reverberated waves Ri(t) from the medium to be imaged are then consecutively detected, following the transmission of the n incident waves; then n elemental reverberated waves R0i(t) are determined by linearly combining the detected n reverberated waves Ri(t) with a decoding matrix Hd. The Hc and Hd matrices are such that Hc.Hd=D, where D is a diagonal matrix of order n, all the diagonal elements of which are greater than 1.

A device, system, and method for volumetric ultrasound imaging is described. The device and system include an array of transducer elements grouped in triangular planar facets and substantially configured in the shape of a hemisphere to form a cup-shaped volumetric imaging region within the cavity of the hemisphere, A plurality of data-acquisition assemblies are connected to the transducers, which are configured to collect ultrasound signals received from the transducers and transmit image data to a network of processors that are configured to construct a volumetric image of an object within the imaging region based on the image data received from the data-acquisition assemblies.

A dual-mode ultrasound system provides real-time imaging and therapy delivery using the same transducer elements of a transducer array. The system may use a multi-channel driver to drive the elements of the array. The system uses a real-time monitoring and feedback image control of the therapy based on imaging data acquired using the dual-mode ultrasound array (DMUA) of transducer elements. Further, for example, multi-modal coded excitation may be used in both imaging and therapy modes. Still further, for example, adaptive, real-time refocusing for improved imaging and therapy can be achieved using, for example, array directivity vectors obtained from DMUA pulse-echo data.

An ultrasound imaging system (102) includes a transducer array (108) with a two-dimensional non-rectangular array of rows (110) of elements, transmit circuitry (112) that actuates the elements to transmit an ultrasound signal into a field of view, receive circuitry (114) that receives echoes produced in response to an interaction between the ultrasound signal and a structure in the field of view, and a beamformer that processes the echoes, thereby generating one or more scan lines indicative of the field of view.

Provided is a technique that implements harmonic imaging in an ultrasound diagnostic apparatus, being unaffected by the voltage-dependent distortion and nonlinear characteristics of the transmit system in the ultrasound diagnostic apparatus that incorporates the transmit amplifier, the ultrasound probe, and the like, facilitating adjustment of the transmit voltage, and achieving a frame rate substantially equivalent to that of the conventional PI method. In the amplitude modulation method that synthesizes the transmit acoustic fields, thereby eliminating a basic wave component of an acoustic wave and creating an image from nonlinear component echoes being extracted, one transmit and receive out of plural transmits and receptions to obtain one scanning line also serves as the transmit and receive for obtaining other scanning line. The echo signals obtained by the shared transmit and receive are used to form the receive beams respectively on both the scanning lines that share the transmit and receive.

A device, system, and method for volumetric ultrasound imaging is described. The device and system include an array of transducer elements grouped in triangular planar facets and substantially configured in the shape of a hemisphere to form a cup-shaped volumetric imaging region within the cavity of the hemisphere, A plurality of data-acquisition assemblies are connected to the transducers, which are configured to collect ultrasound signals received from the transducers and transmit image data to a network of processors that are configured to construct a volumetric image of an object within the imaging region based on the image data received from the data-acquisition assemblies.