Feature Of The Week 3/14/10: Multimodal Imaging with Integrated Photoacoustic Microscopy and Optical Coherence Tomography
Feature Of The Week 3/14/10: Photoacoustic Ophthalmoscopy (PAOM) is based on Laser-scanning Optical Resolution Photoacoustic Microscopy (LS-OR-PAM), which is a branch of photoacoustic microscopy (PAM). LS-OR-PAM was first developed with the collaboration of Dr. Hao Zhang's lab at University of Wisconsin-Milwaukee and Dr. Shuliang Jiao lab at University of Southern California.
PAOM detects the photoacoustic signal induced by pulsed laser light shined onto the retina. By using a stationary ultrasonic transducer in contact with the eyelids and scanning only the laser light across the retina, PAOM provides volumetric imaging of the retinal micro-vasculature and retinal pigment epithelium at a high speed. For B-scan frames containing 256 A-lines, the current PAOM has a frame rate of 93 Hz, which is comparable with state-of-the-art commercial spectral-domain optical coherence tomography (SD-OCT). By integrating PAOM with SD-OCT, we further achieved OCT-guided PAOM, which can provide multi-modal retinal imaging simultaneously. The integrated system can provide optical absorption and scattering contrasts in biological tissues. The multi-modal images are intrinsically registered. The capabilities of this novel technology were demonstrated by imaging both the microanatomy and microvasculature of the rat retina in vivo.