Reconstruction of photoacoustic tomography with finite-aperture detectors: deconvolution of the spatial impulse response

Abstract

In this study, we introduce a new reconstruction method developed to reduce the finite aperture effect in photoacoustic tomography with finite-aperture detectors. The finite aperture effect and degradation in tangential resolution result from the spatial impulse response of the finite-size flat transducer. The proposed method is based on a linear, discrete model of the photoacoustic tomography system in matrix formalism. Using this model, a spatiotemporal deconvolution filter designed in minimum mean square error sense is used to compensate the spatial impulse responses associated with a finite-size flat transducer at each imaging point; thus restoration of the tangential resolution can be achieved retrospectively. The performance of the proposed reconstruction method is verified using simulation data. Compared with that reconstructed by the backprojection algorithm, the proposed method provides uniform tangential resolution over the imaging area while retaining the radial resolution because the full geometry of the flat transducer, instead of the simplified point-detector approximation is taken into consideration. © 2010 Copyright SPIE - The International Society for Optical Engineering.