Full-view volumetric photoacoustic imaging using a hemispheric transducer array combined with an acoustic reflector

Photoacoustic computed tomography (PACT) has evoked extensive interest for applications in preclinical and clinical research. However, the current systems suffer from the limited view provided by detection setups, thus impeding the sufficient acquisition of intricate tissue structures. Here, we propose an approach to enable fast 3D full-view imaging. A hemispherical ultrasonic transducer array combined with a planar acoustic reflector serves as the ultrasonic detection device in the PACT system. The planar acoustic reflector can create a mirrored virtual transducer array, and the detection view range can be enlarged to cover approximately 3.7 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>π</mml:mi></mml:math> steradians in our detection setup. To verify the effectiveness of our proposed configuration, we present the imaging results of a hair phantom, an in vivo zebrafish larva, and a leaf skeleton phantom. Furthermore, the real-time dynamic imaging capacity of this system is demonstrated by observing the movement of zebrafish within 2 s. This strategy holds great potential for both preclinical and clinical research by providing more detailed and comprehensive images of biological tissues.