Ultrasound and photoacoustic imaging

Photoacoustic imaging allows obtaining optical contrast deep within tissues, beyond the limits of optical scattering. When a nanosecond pulse of light is sent into tissue, the scattered photons encounter a chromophore and generate very brief heating, which, through a thermoelastic effect, generates an ultrasonic wave. After propagation, measuring the acoustic waves at the tissue surface allows an optical contrast image to be reconstructed at acoustic resolution (typically 100 µm). We are developing new systems and methods to improve image quality with the aim of introducing new diagnostic tools in the clinical field. Blood vessel oxygenation imaging is a subject of interest and is being addressed through coupling with Doppler ultrasound imaging to improve quantitative aspects.