Fig. 1. Schematic mechanism of acoustic reflectors for PAI. (a) System setup; (b) the original probe has two virtual probes corresponding to two reflectors.

Fig. 2. Phantom experiment. (a) The schematic of the imaging setup; (b) a photograph of the imaging setup; (c) and (d) PA results without and with reflectors, respectively.

Fig. 3. In vivo animal experiment. (a) The schematic of the imaging setup; (b) a photograph of the imaging setup; (c) and (d) fused PA/US results reconstructed without and with two reflectors, respectively. L, left; R, right.