Fig. 1.

Schematics of the experimental setups and imaging targets. Experimental setups for (a) laser illumination and (b) xenon flash lamp illumination. Targets used in the experiments: (c) pure latex cord, (d) pencil leads laid on an agar–water gel, (e) latex cords sandwiched by pieces of chicken breast tissue with the same thickness, (f) blood-filled tube embedded in agar–water gel, and (g) a live mouse. The dashed circles in (a)–(e) represent the scanning trajectory of the ultrasonic transducer. A ring-shaped ultrasonic transducer array was used for targets (f) and (g).