Abstract
The authors demonstrate in vivo dynamic process imaging using a label-free real-time optical-resolution photoacoustic microscope (OR-PAM). This reflection-mode system takes advantage of a 532-nm fiber laser source with a high pulse repetition rate of up to 600 kHz combined with a fast-scanning mirror system. Microvasculature in SCID mouse ears is imaged at near real-time (0.5 fps) for a 1×1 mm2 field of view (FOV) with micron-scale lateral resolution. We also demonstrate imaging of cardiac-induced microhemodynamics in murine microvasculature at real-time frame-rates (30 fps) over a 250×250 μm2 FOV using real-time C-scan OR-PAM with ability to provide sustained imaging with near real-time feedback for focusing and positioning.
Highlights
Optical-resolution photoacoustic microscopy (OR-PAM) is an emerging imaging technology with high lateral resolution due to tightly focused micron-scale laser spot size, and high contrast in tissue based on optical absorption
OR-PAM was reported to realize in vivo imaging of amyloid plaques in a transgenic mouse model of Alzheimer’s disease,[7] as well as longitudinal monitoring of angiogenesis in a transgenic mouse model,[8,9] demonstrating the potential to monitor the efficacy of anti-angiogenic therapies
We report in vivo label-free reflection-mode realtime OR-PAM imaging of micro-hemodynamics correlated with cardiac pulsations and anticipate this system can play an important role in future functional imaging studies of neuronal-hemodynamic coupling
Summary
Optical-resolution photoacoustic microscopy (OR-PAM) is an emerging imaging technology with high lateral resolution due to tightly focused micron-scale laser spot size, and high contrast in tissue based on optical absorption. In order to extend the applications of OR-PAM to clinical applications, ease of use and real-time operation will be key factors to be implemented. Both laser pulse repetition rate (PRR) and scanning speed are important factors affecting the imaging speed. Hu et al.[10] developed a second-generation OR-PAM system based on mechanical translation of an imaging head. They reported a 70-min image acquisition time for a 7.8 × 10 mm[2] FOV with a pixel size of 2.5 × 2.5 μm[2]. The system enabled fast scanning speed but with imaging speed limited
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call