Quantitative photoacoustic imaging of simulated carotid plaques in a neck phantom

We present a new curved array-based photoacoustic and ultrasound imaging system, targeted at imaging and characterising atherosclerotic plaques in the carotid artery. The system incorporates an imaging probe with a 256-element ultrasound array as a detector and ultrasound source, a custom fibre bundle with a pair of linear outputs for illumination and a moulded polyvinyl chloride plastisol acoustic interface piece. The initial results presented here focus on an assessment of the imaging depth in a gelatin-based neck-mimicking phantom with channels representing the carotid artery at various depths. We report imaging depths down to 40 mm, which would be an adequate depth for imaging the carotid artery in most patients. Further we present our initial results on unmixing different chromophores embedded in the phantom.