A new extension of DMAS ultrasound nonlinear beamformer using the third degree terms with low computational complexity

The paper investigates an extended version of delay-multiply-and-sum (DMAS), which is robust against artifacts and noise, and enhances image resolution without compromising the contrast. The proposed method (DMAS3) extends the dimension of the summation to three and leads to more synthetic observations; M/3 times than DMAS with $M$ observations. While a huge computational load is expected for the summation with the 3rd degree terms, the proposed method with a linear expression results in the same imaging and a reduced computational load. Another important concept to consider is the required memory to implement the technique. The increment in the memory demand in the proposed method is also linear compared to DAS which is a principal factor for real time execution of the approach on the clinical platforms and makes it possible to implement on on-the-shelf hardware easily. Simulated results depicted that the proposed method offers an improvement of 29% and 14% in FWHM (Full Width at Half Maximum) and an increase of 4.57 dB and 3.05 dB in Peak-Sidelobe-Level (PSL) in wire phantom while an improvement of 10.14 dB and 0.37 dB in terms of CR (contrast ratio) in cyst phantom compared to DAS and DMAS methods, respectively.