Feasibility of quantitative determination of local optical absorbances in tissue-mimicking phantoms using acousto-optic sensing

We have investigated the application of ultrasound modulation of coherent light for quantitative determination of local absorbances in tissue-mimicking phantoms. An Intralipid-based phantom model, which mimics a blood vessel in human tissue, was used. The detection technique was based on homodyne parallel speckle detection in transmission mode. Based on a comparison of experimental data and Monte Carlo simulations, a quantitative correlation between local absorbances of the phantom and the measured signal has been shown. The use of microsecond pulses of ultrasound and laser light resulted in a spatial resolution of the system of a few millimeters