Optical Coherence Tomography

OCT is a low-coherence interferometer-based noninvasive medical imaging modality that can provide high-resolution sectional images of biological tissues. Since it was first reported more than two decades ago, OCT has been used in a variety of medical research and diagnostic applications with the most successful being in ophthalmology for retinal sectional imaging. The interference signals of OCT can be detected in either time domain (TD-OCT) or spectral domain (SD-OCT). Spectral-domain detection has the advantages of fast imaging speed and better signal-to-noise ratio. Currently, SD-OCT has become one of the major retinal imaging techniques in ophthalmic clinics.

Dr. Jiao’s lab pioneered the use of high-resolution SD-OCT in imaging small animal models of ocular diseases. Currently, SD-OCT plays an important role in ophthalmic research using animal models.

Photoacoustic Microscopy

PAM is an optical-absorption based microscopic imaging modality that detects laser-induced ultrasonic waves (photoacoustic waves) as a result of specific optical absorption. Photoacoustic ophthalmoscopy (PAOM) is a branch of PAM. PAOM is capable of imaging the physiologically-specific optical absorption contrast in the retina, which is missing in all existing ophthalmic imaging modalities. PAOM was first introduced in 2010 by Dr. Jiao’s lab together with his collaborators and has since achieved high-speed, high-resolution in vivo imaging of the vasculature of the retina and the pigmentation of the RPE in small animals.

Auto Fluorescent Imaging 

Optical coherence tomography (OCT), retinal autofluorescence (AF) imaging, and fluorescein angiography (FA) are three important imaging modalities in both ophthalmic clinics and research, which image different aspects of the retina. Retinal AF imaging maps the distribution of lipofuscin, the major source of AF in the retinal pigment epithelium (RPE). FA images fluorescence from exogenous contrast molecules administrated into the blood stream to capture the blood circulations and identify vascular leakage in the retina.

Multimodal imaging

Multimodal imaging takes advantages of combining different contrast mechanisms to provide comprehensive anatomical and functional information of biological tissues. PAOM and OCT, PAOM and Auto Fluorecence imaging, and OCT and autofluorescence imaging are imaging modalities that can provide complementary contrasts for imaging biological tissues and are good candidates for an integrated multimodal system.