Feasibility of an ultra-compact, wireless ultrasound and photoacoustic imaging system (wUS-PA)

Photoacoustic imaging (PAI) is a hybrid imaging technique providing optical contrast with ultrasound resolution for deep tissue imaging. Currently, dual-mode ultrasound+photoacoustic (US+PA) imaging systems are bulky and expensive. In this work, we demonstrate the feasibility of a low-cost, ultra-compact, portable dual-mode US and PA imaging system (wUS-PA) using a wireless ultrasound platform. We adapted L15 HD 3 (Clarius) to operate as a dual-mode US and PA imaging system. A compact pulsed laser diode was used as an illumination source to study the feasibility of wUS-PA imaging. The designed wUS-PA system was characterized by various phantom experiments to quantify spatial resolution, sensitivity, imaging depth, and frame rate. For a 4-cm imaging depth, the system can image up to 17 frames/second with 150 µm and 300 µm axial and lateral resolution, respectively. The PA imaging depth in chicken tissue was ~2 cm.