USING A PHASE CONTRAST IMAGING METHOD IN PHOTOACOUSTIC TOMOGRAPHY

To speed up the data acquisition in photoacoustic tomography full field detection can be used to avoid the time consuming scanning around the object. The full field detection is realized using a phase contrast method like commonly used in optical microscopy. An expanded light beam considerably larger than the object size illuminates the sample placed in the middle of the propagating light beam. Images obtained with a CCD-camera at a certain time show a projection of the instantaneous pressure field (phase object) in a given direction. The reconstruction method is related to imaging with integrating line detectors, but has to be matched to the specific information in the recorded images, which is now purely spatially resolved as opposed to spatiotemporally for a single scanning detector. The reconstruction of the projection images of the initial pressure distribution is done by back propagating the observed wave pattern in Radon space. Numerical simulations and experiments are performed to show the overall adaptability of this technique in photoacoustic tomography.