Section-illumination photoacoustic microscopy for dynamic 3D imaging of microcirculation in vivo.

We developed section-illumination photoacoustic microscopy capable of dynamic in vivo imaging of microvessels as small as 30 microm in diameter. The section illumination improved the elevational resolution while an ultrasound array provided the in-plane axial and lateral resolutions. Using the imaging system, we monitored the wash-in dynamics of Evans Blue in the microcirculation of mouse ears at 249 Hz 2D and 0.5 Hz 3D image acquisition rates. Such observation allowed us to differentiate the arterioles from the venules. In the future, the technology may be used to study angiogenesis, diabetes-induced vascular complications, and pharmacokinetics.