In vivo functional chronic imaging of a small animal model using optical-resolution photoacoustic microscopy
Optical-resolution photoacousticmicroscopy (OR-PAM) has been validated as a valuable tool for label-free volumetric microvascular imaging. More importantly, the advantages of noninvasiveness and measurement consistency suggest the use of OR-PAM for chronic imaging of intact microcirculation. Here, such chronic imaging is demonstrated for the first time by monitoring the healing process of laser-induced microvascular lesions in a small animal model in vivo. The central part of a 1 mm by 1 mm region in a nude mouse ear was treated under a continuous-wave laser to create a microvascular lesion for chronic study. The region of interest was imaged before the laser treatment, immediately after the treatment, and throughout the healing process using both the authors' OR-PAM system and a commercial transmission-mode optical microscope. Three-dimensional microvascular morphology and blood oxygenation information were imaged simultaneously at capillary-level resolution. Transmission-mode optical microscopic images were acquired for comparison. OR-PAM has potential important applications in microcirculatory physiology or pathophysiology, tumor angiogenesis, laser microsurgery, and neuroscience.
Additional Information© 2009 American Association of Physicists in Medicine. Received 27 February 2009; Revised 16 April 2009; Accepted 26 April 2009; Published online 27 May 2009. The authors appreciate Professor James Ballard's close reading of the manuscript. This work was sponsored by National Institutes of Health Grant Nos. R01 EB000712, R01 NS46214 (Bioengineering Research Partnerships), R01 EB008085, and U54 CA136398 (Network for Translational Research). L.V.W. has a financial interest in Endra, Inc., which, however, did not support this work.
Published - MPHYA6-000036-002320_1.pdf