Abstract: Velocity scale is automatically determined for ultrasound imaging. Receive signals corresponding to different pulse repetition intervals are used to estimate velocities. The different velocities are used to determine the velocity scale. For example, the different pulse repetition intervals are obtained by selecting different sets of signals from a group of signals for a scan line. As another example, the different pulse repetition intervals are obtained by transmitting for a scan line with changing, such as increasing, pulse repetition intervals. The lower pulse repetition interval of a pair of intervals associated with a sign change in the phase is used for the velocity scale. In yet another example, at least two demodulation frequencies are used for a broadband transmit in at least two sets, each set with a different pulse repetition interval. Velocities are estimated for a greater number of pulse repetition intervals than transmitted using the broadband pulses.

Abstract: Methods are provided for automatic setting of parameters for contrast agent quantification. Various processes may improve quantification. For example, for consistency in contrast agent quantification, a gain or other setting of an ultrasound system is automatically determined in response to destruction of the contrast agent or at the initiation of the contrast agent quantification procedure. Automatic setting of an adaptive gain provides equalized image intensity for each repetition of a contrast agent quantification procedure based on a same triggering event, the destruction of contrast agent. By synchronizing the adaptive setting algorithms with contrast agent destruction, similar base line information is provided for each iteration of a contrast agent quantification procedure. As another example, the contrast agent gain setting treats acoustic signals representing tissue or other non-contrast agent structure as noise, mapping the tissue values to a substantially constant low value within the dynamic range.

Abstract: Transmit based axial whitening is provided. Ultrasonic waveforms to be transmitted are designed to provide for wideband imaging characteristics prior to detection. Rather than transmitting a waveform having a spectral magnitude as white or flat as possible, waveforms with adjusted spectral content, such as spectrally bi-modal waveforms are generated in order to compensate for subsequent effects. Prior to detection, a more wideband or whiter signal response is provided in response to the transmitted waveform. Any of various alterations of the transmit waveform, such as asymmetric, spectrally bi-modal or other characteristics in anticipation of a system transfer function or physical phenomena through which the signal passes electronically or acoustically to result in a wideband or white spectral magnitude and generally linear spectral phase is used. The transmit waveform is altered to improve the imaging characteristics of the downstream processing.