Aberration correction using broad transmit beams

A new tissue aberration correction method is described that is compatible with imaging techniques that use weakly focused, unfocused or defocused transmit beams. This method is based on the principle of reciprocity. Rather than relying on a focused transmit beam to create a virtual point source, we use a focused receive beam to do the same. The data acquisition scheme is to transmit with a virtual element, receive echoes with all the elements and store the channel data, and form a receive focus at a point of interest. As the transmit virtual element number is varied, the beamsum from receive focusing also varies. The ensemble of receive beamsums are processed (e.g. cross-correlated) to extract information about aberration. More generally, dynamic and parallel receive beams are formed to produce single-transmit images. These are correlated to improve the stability of aberration estimation. The estimated aberration information can be used to compensate the receive focus, and the process can be iterated without acquiring new data. Aberration for any insonified region can be estimated by steering the receive focus to that region. A synthetic image is formed with correction applied on both receive beamformation and transmit synthesis.