Adaptive compounding of synthetic aperture and compounded plane-wave imaging for fast ultrasonography

This paper describes the investigation and implementation of a combined synthetic aperture (SA) and compounded plane wave (CPW) ultrasound imaging technique. Individually, these methods offer unique benefits over the conventional transmit beamforming used in ultrasonography (higher resolution and increased signal-to-noise ratio, respectively), and both have the potential for a higher physical frame rate limit. The technique described combines the individual benefits while maintaining a higher frame rate, by adaptively compounding the resulting images from SA and CPW sequences at half the standard number of transmits. Tests on a phantom with both point scatterers and occlusions showed overall improvements of 14.5% in lateral resolution and 7.5% in axial resolution over CPW, and a 14.5 dB improvement in signal-to-noise ratio (SNR) for occlusions over SA. Both resolution and SNR were an improvement over that for conventional transmit beamforming with two focus depths, and offer double the physical frame rate limit.