Basic study of improvement of axial resolution and suppression of time side lobe by phase-corrected Wiener filtering in photoacoustic tomography

In this paper, we propose a reconstruction method to improve axial resolution through the suppression of the time side lobes in photoacoustic tomography by phase-corrected Wiener filtering and thresholding. Two experiments using spherical and vessel targets were performed to validate the effect of the proposed method. The proposed method could reduce the time side lobe level by about %7 dB for both targets and improve the axial resolution from 102 to 43 µm for the spherical target. The method could maintain or even enhance the continuity of in vivo micro vasculatures in a human hand through phase shift rewinding due to propagation to the phase suitable for thresholding. We believe that the proposed method will improve the quality of photoacoustic images in clinical applications.