Ultrasound imaging using apparent point-source transmit transducer

An ultrasound probe comprising:

• A three-dimensional spherically-shaped transmit array comprising one or more omnidirectional transmit transducer elements, the omnidirectional transmit transducer elements being configured to transmit a three-dimensional ultrasound wavefront to insonify a region of interest with a point source location that appears to have originated from an apparent point source that lies somewhere other than a surface of the transmit array;
• a first receive array comprising a plurality of omnidirectional receive transducer elements, the first receive array configured to receive echoes of the three-dimensional ultrasound wavefront from one or more scatterers within the region of interest;
• and
• beamforming electronics configured to produce a three-dimensional sub-image of the one or more scatterers within the region of interest from received echoes at each of the plurality of omnidirectional receive transducer elements based on a transmission time of the three-dimensional ultrasound wavefront from the point source location to the one or more scatterers and to the plurality of omnidirectional receive transducer elements, the transmission time accounting for a distance between the apparent point source and the surface of the transmit array, the beamforming electronics being further configured to coherently combine the three-dimensional sub-images to form a three-dimensional image of the one or more scatterers within the region of interest, the three-dimensional image having improved image quality relative to the three-dimensional sub-images.