Photoacoustic　(PA)　imaging　is　a　nonionizing,　noninvasive　imaging　technique　that　combines　optical　and　ultrasonic　imaging　modalities　to　provide　images　with　excellent　contrast,　spatial　resolution,　and　penetration　depth.　Exogenous　PA　contrast　agents　are　created　to　increase　the　sensitivity　and　specificit...