Figure 1.

Schematic diagram of the developed handheld dual-modality US/PA imaging system with fiber bundle-based illumination. (A) Experimental setup of the developed PA system. A PC user interface including a control panel and program selection was integrated with a multichannel Verasonics US system and a pulsed laser system. (B) Photograph of the developed PA probe, which includes the removable fiber bundle-based illumination system (left), one US transducer, and a customized jacket (right). Photograph of the input and output ends of the fiber bundle (middle). The output end of the fiber bundle consisted of two rectangular parts, while the input end was circular. A zoomed-in section of the handheld PA probe fixed on an in-house scanning stage, showing the fiber jacket with the fibers and transducer, is displayed. US, ultrasound; PA, photoacoustic; Nd:YAG, neodymium-doped yttrium aluminum garnet; PC, personal computer; OPO, optical parametric oscillator; TR, ultrasound transducer.