Dynamic in vivo imaging of small animal brain using pulsed laser diode-based photoacoustic tomography system

Abstract

We demonstrate dynamic in vivo imaging using a low-cost portable pulsed laser diode based photoacoustic tomography system. The system takes advantage of an 803 nm pulsed laser diode having high repetition rate ~7000 Hz combined with a fast-scanning single-element ultrasound transducer leading to a 5 seconds cross-sectional imaging. Cortical vasculature is imaged in scan-time of 5 seconds with high signal-to-noise ratio ~48. To examine the ability for dynamic imaging, we monitored the fast uptake and clearance process of indo-cyanine green in the rat brain. The system will find applications to study neuro-functional activities, characterization of pharmacokinetic and bio-distribution profiles in the development process of drugs or imaging agents.