Real-time optoacoustic imaging using a Schlieren transducer

Optoacoustics, which combines the merits and most compelling features of light and sound, is a technique for diagnosing optical tissue properties and for performing noninvasive medical imaging. We present a detection method based on Schlieren optical imaging used to record optoacoustic waves generated with 6 ns long laser pulses. These waves result from irradiation of optically absorbing targets hidden deep inside highly scattering media. Since they are generated from one single shot, Schlieren images contain all the information necessary for the reconstruction of the absorbing structures. The detection method allows on-line imaging with a spatial resolution of about 30 mum with high contrast. The proposed real-time imaging system not only enhances the level of visible detail but it is ideally suited for monitoring dynamic tissue changes. (C) 2002 American Institute of Physics.