Real-time handheld optical-resolution photoacoustic microscopy.

In this paper a new generation of optical-resolution photoacoustic microscopy (OR-PAM) with a wide range of potential clinical applications is demonstrated. Using fast scanning mirrors, an image guide with 30,000 fiber pixels, a refocusing lens and a unique probe we managed to reduce the footprint of an OR-PAM system from a stationary table-top system to a portable, 4 cm by 6 cm, probe weighing ~500 g tethered to a scanning unit. The phantom studies show that the handheld optical-resolution photoacoustic microscope is able to image with ~7 μm resolution. For in vivo studies images of the microvasculature in a Swiss Webster mouse ear are shown. The compact, flexible nature of the proposed design and the small footprint of the apparatus increase the usability of OR-PAM for potential clinical applications such as in dermatology.