News

December 13, 2017

University Ph.D. Dissertation Defense
Department of Electrical Engineering

Orly Liba

Computational and optical tools for enabling high-resolution in vivo functional imaging with optical coherence tomography 

Advisor: Adam de la Zerda

Date: Wednesday, December 13, 2017
Time: 10:30 am (refreshments at 10:15 am)
Location: Clark Center Room S360, 318 Campus Drive

Optical Coherence Tomography (OCT) enables real-time imaging of living tissues at cell-scale resolution over millimeters in three dimensions. Despite these advantages, functional biological studies and clinical applications of OCT have been limited.

The first limitation that I addressed in my research is the lack of exogenous contrast agents for OCT. Such contrast agents can be beneficial for functional and molecular imaging, by labeling specific proteins or cells, and providing a better understanding of the underlying biological processes in the tissue in addition to its structure, which is provided by conventional OCT. My lab and I addressed this limitation by developing uniquely spectral large gold nanorods (LGNRs) and custom algorithms to spectrally identify the LGNRs in tissue.

A second limitation of OCT is the speckle noise caused by coherent interference of multiply scattered light, which hides fine tissue structures and also hinders the detection of our contrast agent. I developed a method for removing speckle noise in OCT by modulating the phase of the light illuminating the sample. By removing the speckle noise, speckle-modulating OCT (SM-OCT) was able to reveal tissue structures in living mice and humans. Notably, the demonstrated improved imaging of brain tissue can be beneficial for intra-operative tumor margin detection and for neurological studies of small animals. The combination of SM-OCT with our contrast agent was used for labeling and tracking leukocytes in brain tumors in vivo.