Shuliang Jiao, Ph. D.
Research Assistant Professor

View published research articles by this doctor in the National Library of Medicine.

Research Interests: New technology and application system development in Optical Coherence Tomography (OCT); Polarimetry in Biological Tissues.

Current Research Program: OCT has been used in a variety of medical research and diagnostic applications with the most successful being in ophthalmology for retinal sectional imaging. OCT has become one of the standard non-contact noninvasive ophthalmic imaging modalities for routine clinic diagnosis. The main focus areas of OCT research are (1) high spatial resolution; (2) high imaging speed; (3) image registration; (4) quantitative information extraction; (5) new contrast mechanisms.

The recent development of spectral-domain OCT has made it possible to collect 3-dimensional (3D) image data. From the measured data, either the raw spectra or the processed OCT data, an en face fundus image (OCT fundus image) similar to the fundus images acquired with a scanning laser ophthalmoscope (SLO) can be generated. By simply tuning of the cutoff frequency of the high pass filter used for the raw spectra the image quality of the OCT fundus image can be adjusted.

The spatial location of each OCT sectional image is registered on the OCT fundus image automatically if the fundus image is generated from the same measured OCT data set. This technique solves a major problem in ophthalmic OCT practice.

The task of OCT image registration also include registering OCT sectional images to other imaging modalities like fundus photograph and fluorescein angiogram by using of the OCT fundus image, precise spatial registration of 3-D OCT images acquired before and after treatment to monitor the effectiveness of treatment and progression of the disease.

The fast image acquisition speed of spectral-domain OCT also has an advantage in generating high pixel density OCT images through lateral over-sampling. High density OCT images can significantly improve the image quality and enhance the visualization of retinal structure and especially the structure of small lesions. However, for a particular imaging speed, the total number of axial scans (A-scan) in a certain period of time is fixed. The longest image acquisition time is determined by the time during which the patient can effectively focus the eye on a fixation target. As a result, for a raster scan pattern, increasing the line density for an OCT sectional image in the horizontal direction requires a decrease of the line density in the vertical direction. If the covered areas in the retina for the two scan patterns are the same, the high density scan patterns can not generate an effective fundus image for registration purposes.  We have been developing techniques to register a high density OCT image on the fundus image generated from normal density scans.

Polarization-sensitive OCT (PS-OCT) is a branch of functional OCT, which measures the polarization properties of biological tissues. Polarization properties are related to various biological components such as collagen, muscle fibers, myelin, retinal nerve fiber layer, keratin and glucose. Polarization can provide novel contrast mechanisms for imaging, diagnosis, and sensing. The combination of polarimetry with OCT makes it possible to image the polarization properties of biological tissues with OCT resolution. PS-OCT has potential applications in glaucoma study.