Deconvolution Algorithm with LTI Wiener Filter in Photoacousic Tomography

In order to improve the imaging contrast in photoacoustic tomography, the frequency spectrum of photoacoustic signal should be restored by deconvolving the transducer impulse response out of the photoacoustic signal of the tissue phantom. But it is difficult to generate photoacoustic impulse of a temporal delta function in experiment. To solve the problem, a method that the photoacoustic impulse was produced by a point optical absorber was proposed. The relationship between the transducer frequency response to a temporal delta function and a point optical absorber was studied. A LTI wiener filter was used during deconvolution in order to suppress noise adaptively. The photoacoustic image was finally reconstructed by time-domain spherical back projection algorithm. The feasibility of the method was demonstrated both by numerical simulation and experiment.