Label-free optical-resolution photoacoustic endomicroscopy in vivo
Intravital microscopy techniques have become increasingly important in biomedical research because they can provide unique microscopic views of various biological or disease developmental processes in situ. Here we present an optical-resolution photoacoustic endomicroscopy (OR-PAEM) system that visualizes internal organs with a much finer resolution than conventional acoustic-resolution photoacoustic endoscopy systems. By combining gradient index (GRIN) lens-based optical focusing and ultrasonic ring transducer-based acoustic focusing, we achieved a transverse resolution as fine as ~10 μm at an optical working distance of 6.5 mm. The OR-PAEM system's high-resolution intravital imaging capability is demonstrated through animal experiments.
Additional Information© 2015 Society of Photo-Optical Instrumentation Engineers. We thank Professor James Ballard for his attentive reading of the manuscript. This work was sponsored in part by National Institutes of Health grants R01 CA157277, DP1 EB016986 (NIH Director's Pioneer Award), P41-EB002182, and R01 CA186567 (NIH Director's Transformative Research Award). L.W. has a financial interest in Microphotoacoustics, Inc. and Endra, Inc., which, however, did not support this work. K.M. has a financial interest in Microphotoacoustics, Inc.
Published - 932332.pdf