Contrast detection efficacy for plane vs. focused wave transmission

Plane-wave transmission with high number of compounding angles has been suggested as a means to produce good quality images at pressure levels that do not destroy ultrasound contrast agents (UCA). In this paper, a programmable research platform is used to compare the contrast obtained by focused (F) and angled plane wave (APW) power modulation (PM) UCA imaging. The acoustic pressure levels were below 140 kPa in a phantom setup. The contrast in F-PM is typically 0.5 to 1 dB higher than in single-angle APW-PM. However, compounding significantly improves the contrast, especially at low transmit power, by 7 to 10 dB and APW-PM outperforms F-PM. This increase is attributed mainly to noise reduction caused by the coherent summation of angled plane waves. This data shows that APW-PM is more sensitive.