Abstract: To generate information representing a volume, co-arrays or synthetic transmit aperture process is performed in one dimension and beamforming is performed in another dimension. For example, a transmit aperture focuses in azimuth, but is unfocused or divergent in elevation. A multi-dimensional array receives reflected echoes. The echoes are beamformed for sub-arrays for focus in azimuth. The resulting partial beamformed information is provided to an imaging system from the probe housing for completion of beamforming at least in elevation.

Abstract: Ultrasound information for B-mode and CW Doppler mode use the same digital beamformer. Due to sigma-delta conversion or over sampling, sufficient dynamic range is provided for the desired bandwidth. By mixing the input ultrasound information to base band before conversion, additional dynamic range may be provided. The electrical impedance may be better matched to elements by connecting a different number of sigma-delta converters to an element. Elements with lower impedance may be connected to a plurality of sigma-delta converters. To increase the aperture size for elements with a higher impedance, the same sigma-delta converters may be used as separate receive beamformer channels without the summation.

Abstract: Receive beamformers for receive beamforming ultrasound information include a plurality of channels. The received signals for each channel are oversampled for conversion to digital form, such as sampling with a sigma-delta converter. The reconstruction of the samples into data at the Nyquist or other rate is performed in stages. Partial reconstruction to a rate less than the oversampling rate, but greater than the Nyquist rate, occurs prior to summation across channels. Delays are implemented by selecting data from the sample stream. After summation, the samples are reconstructed at a Nyquist or other rate.

Abstract: Using configurable arrays, synthetic aperture processes may be used along an elevation dimension for increasing resolution. The increased resolution is used for two-dimensional or three-dimensional imaging. Alternatively or additionally, wide band synthetic elevation aperture focusing processes, such as beamformation, are provided along the elevation dimension to increase resolution. In yet another alternative or additional embodiment, a transducer is rotated about a center of the transducer within the elevation and azimuth plane. An aperture associated with the transducer is mechanically or electronically rotated, and ultrasound data acquired associated with a plurality of different positions. The ultrasound data is then used for synthetic elevation aperture processing. In yet another alternative or additional embodiment, multiple scanning modes are provided. In a survey mode, imaging is provided without synthetic elevation aperture processing.

Abstract: Using configurable arrays, synthetic aperture processes may be used along an elevation dimension for increasing resolution. The increased resolution is used for two-dimensional or three-dimensional imaging. Alternatively or additionally, wide band synthetic elevation aperture focusing processes, such as beamformation, are provided along the elevation dimension to increase resolution. In yet another alternative or additional embodiment, a transducer is rotated about a center of the transducer within the elevation and azimuth plane. An aperture associated with the transducer is mechanically or electronically rotated, and ultrasound data acquired associated with a plurality of different positions. The ultrasound data is then used for synthetic elevation aperture processing. In yet another alternative or additional embodiment, multiple scanning modes are provided. In a survey mode, imaging is provided without synthetic elevation aperture processing.

Abstract: Adaptive line synthesis is provided. Line synthesis of collinear receive beams responsive to spatially distinct transmit beams is a function of many parameters, such as spatial or temporal frequency response of one or more of the receive beams, synthesis function, number of receive beams synthesized, or acquisition sequence. One or more of these parameters is set or adapts as a function of processor estimated or user provided information. By adapting the line synthesis, the performance and image quality is optimized as appropriate for the received data or desired imaging, such as detail resolution, contrast resolution, temporal resolution, shift-invariance and penetration.

Abstract: Aberration estimation uses cross correlation of receive-focused transmit element data. A set of sequentially fired broad transmit beams insonify an object from different steering angles. Each transmit beam emanates from an actual or a virtual transmit element. For every firing, a receive beamformer forms a transmit element image of the insonified region by focusing the received signals. An estimator estimates aberration by cross correlating or comparing the transmit element images. Where a virtual transmit element is used, the virtual transmit element images are back propagated to an actual transmit element position before aberration estimation. The estimations are used to form corrected transmit element images which are then summed pre-detection to form a high-resolution synthetic transmit aperture. Alternatively, the estimations are used to improve conventional focused-transmit imaging.

Abstract: A set of N×M signals are acquired from an object, where N is the number of array elements and M corresponds to variations in data acquisition and/or processing parameters. The parameters include transmit aperture functions, transmit waveforms, receive aperture functions, and receive filtering functions in space and/or time. A coherence factor is computed as a ratio of the energy of the coherent sum to the energy of the at-least-partially incoherent sum of channel or image signals acquired with at least one different parameter. Partial beamformed data may be used for channel coherence calculation. For image domain coherence, a component image is formed for each different transmit beam or receive aperture function, and a coherence factor image is computed using the set of component images. The coherence factor image is displayed or used to modify or blend other images formed of the same region.

Abstract: For imaging, broad transmit beams are used to increase frame rate. Two or more receive beams are formed in response to each of the broad beam transmit operations. For aberration correction, narrow transmit beams are used, such as a beam associated with receiving along a single scan line. By altering a pulse shape or delay profile, the broad and narrow beam patterns are generated. The wavefront coherence of a narrow beam allows for accurate determination of relative time delay differences or other aberration corrections. The narrowly focused transmit beams are directed automatically towards special targets, such as isolated point targets, to further enhance backscattering coherence. The wide transmit beams and associated wavefront allow for more rapid scanning of a two-dimensional area or a three-dimensional volume. Interleaving the two different types of transmit beams allows for use of aberration correction to increase resolution and reduced clutter levels while more quickly scanning a region.

Abstract: Using configurable arrays, synthetic aperture processes may be used along an elevation dimension for increasing resolution. The increased resolution is used for two-dimensional or three-dimensional imaging. Alternatively or additionally, wide band synthetic elevation aperture focusing processes, such as beamformation, are provided along the elevation dimension to increase resolution. In yet another alternative or additional embodiment, a transducer is rotated about a center of the transducer within the elevation and azimuth plane. An aperture associated with the transducer is mechanically or electronically rotated, and ultrasound data acquired associated with a plurality of different positions. The ultrasound data is then used for synthetic elevation aperture processing. In yet another alternative or additional embodiment, multiple scanning modes are provided. In a survey mode, imaging is provided without synthetic elevation aperture processing.