Does medium stiffness affect photoacoustic image intensity? A phantom study

This study investigates the effect of medium stiffness on photoacoustic (PA) image intensity using agar phantoms with varying concentrations. Results show a significant increase in PA signal intensity between 1% and 2% agar, but not between 2% and 4%. Higher stiffness enhances PA signal but increased impedance mismatch and other factors at 4%, such as thermal effects, reduce intensity. Future work will examine the thermal and optical properties’ roles in PA signal behavior.