  Delay-and-Sum (DAS) beamformer is the most common beamforming algorithm in
Photoacoustic imaging (PAI) due to its simple implementation and real time
imaging. However, it provides poor resolution and high levels of sidelobe. A
new algorithm named Delay-Multiply-and-Sum (DMAS) was introduced. Using DMAS
leads to lower levels of sidelobe compared to DAS, but resolution is not
satisfying yet. In this paper, a novel beamformer is introduced based on the
combination of Minimum Variance (MV) adaptive beamforming and DMAS, so-called
Minimum Variance-Based DMAS (MVB-DMAS). It is shown that expanding the DMAS
equation leads to some terms which contain a DAS equation. It is proposed to
use MV adaptive beamformer instead of existing DAS inside the DMAS algebra
expansion. MVB-DMAS is evaluated numerically compared to DAS, DMAS and MV and
Signal-to-noise ratio (SNR) metric is presented. It is shown that MVB-DMAS
leads to higher image quality and SNR for about 13 dB, 3 dB and 2 dB in
comparison with DAS, DMAS and MV, respectively.
