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: 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: 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: Multiple scanning modes are provided. In a survey mode, imaging is provided without synthetic elevation aperture processing. For greater detailed imaging, imaging is responsive to synthetic elevation aperture processes with different elevation focusing and scanning.

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: 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: 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: A method and apparatus for ultrasound breast imaging is described. Breast is positioned in between an ultrasound array and a plate with embedded point or line targets. The apparatus and reflections from the targets are used 1) to improve focusing by correcting for tissue delay and amplitude aberration and 2) to improve diagnostics by constructing speed of sound and attenuation coefficient images.

Abstract: A method and apparatus for ultrasound breast imaging is described. Breast is positioned in between an ultrasound array and a plate with embedded point or line targets. The apparatus and reflections from the targets are used 1) to improve focusing by correcting for tissue delay and amplitude aberration and 2) to improve diagnostics by constructing speed of sound and attenuation coefficient images.

Abstract: Plane waves are transmitted at different incident angles, and the radio frequency echo waveforms received by the elements in an array are processed with a Fourier transform. This method is capable of generating one frame of “raw” image for each transmitted plane wave. The formation of each raw image includes: temporal Fourier transform of radio frequency echo signal from each element; phase rotation; spatial Fourier transform; complex interpolation; and an inverse spatial-temporal Fourier transform. This method does not require the synthesis of limited diffraction beams and is computationally more efficient compared to conventional delay-and-sum approach. These raw images are combined coherently to enlarge spatial frequency coverage and enhance lateral resolution. The resolution-enhanced images are further combined incoherently to achieve speckle reduction.

Abstract: Plane waves are transmitted at different incident angles, and the radio frequency echo waveforms received by the elements in an array are processed with a Fourier transform. This method is capable of generating one frame of “raw” image for each transmitted plane wave. The formation of each raw image includes: temporal Fourier transform of radio frequency echo signal from each element; phase rotation; spatial Fourier transform; complex interpolation; and an inverse spatial-temporal Fourier transform. This method does not require the synthesis of limited diffraction beams and is computationally more efficient compared to conventional delay-and-sum approach. These raw images are combined coherently to enlarge spatial frequency coverage and enhance lateral resolution. The resolution-enhanced images are further combined incoherently to achieve speckle reduction.

Abstract: A system and method for reducing parallel beamforming artifacts. An interpolation of amplitude data is performed to correct for the blocky appearance of images formed with parallel receive beams. In addition, the transmit beam is modified to approximate a rectangular beam.

Abstract: An ultrasound imaging system directs a transmit beam of ultrasound from a plurality of elements in a transducer array into a region of interest (ROI) of a patient's body. The receive beam back from the ROI contains a separate waveform for each of the array elements. These waveforms are partitioned into groups, and a control waveform is determined for each group. The control waveform is then jittered, that is, time-shifted, by a trial delay time, and trial delay times for the other waveforms in the group are determined by interpolation. A waveform similarity factor (WSF), which is preferably a function of the r.m.s. value of the sum of the waveforms in the group, is then evaluated. The control waveform is then repeatedly shifted by different trial amounts, with a new WSF being determined for each trial shift. The trial delay for the control waveform is then assumed to be optimum that yielded the greatest group WSF.