Abstract
Minimum variance (MV) beamformer has been commonly used to improve lateral resolution of photoacoustic imaging. Recently, photoacoustic imaging with 2D array transducer has been increasingly used for 3D imaging; therefore, 2D array beamforming algorithms are required to improve resolution in multiple axes. 2D MV beamformer can improve lateral and elevational resolution simultaneously but suffers high computational complexity which is O(N 6 ). In this article, we proposed a simplified version of 2D MV - double direction MV (DDMV), applying MV on lateral and elevational direction while requiring less computational complexity, which is O(N 4 ). Our simulation results show that, compared with delay and sum beamformation (DAS), DDMV can improve both lateral and elevational resolution by 48.8% and 84.9% respectively, and has similar resolution improvement as 2D MV.