Development of a combined photoacoustic micro-ultrasound system for estimating blood oxygenation

Photoacoustic (PA) imaging can estimate the spatial distribution of oxygen saturation (sO₂) in blood, and be coregistered with B-Mode images of the surrounding anatomy. This study will focus on the development of a PA imaging mode on a commercially available array based micro-ultrasound (μUS) system that is capable of creating such images. The system will then be validated in vivo against a complementary technique for measuring partial pressure of oxygen in blood (pO₂). The pO₂ estimates are converted to sO₂ values based on a standard dissociation curve found in the literature. Beamforming techniques and signal processing will also be described, along with in vivo PA images of subcutaneous murine tumours.