9 - Frontiers in Photophysics and Biomedical Applications
Florida 1 10:00 - 12:00
|Chair(s): (Stephen) Chad Kanick, Bryan Spring|
10:00 In vivo Multiphoton Imaging of Mouse Brain Chris Xu*, Cornell University
Abstract: Over the last two decades, multiphoton microscopy has created a renaissance in the brain imaging community. It has changed how we visualize neurons by providing high-resolution, non-invasive imaging capability deep within intact brain tissue. Multiphoton imaging will likely play an essential role in understanding how the brain works at the level of neural circuits, which will provide a bridge between microscopic interactions at the neuronal level and the macroscopic structures that perform complex computations. In this paper, the fundamental challenges of deep tissue, high-resolution optical imaging are discussed. New technologies for in vivo structural and functional imaging of mouse brain using long wavelength excitation and three-photon microscopy (3PM) will be presented. We will discuss the requirements for imaging the dynamic neuronal activity at the cellular level over a large area and depth in awake and behaving animals. Finally, we will speculate on the possible future directions to further improve the imaging depth and speed in biological tissues.
10:30 Design and optimization of optical-sectioning microscopes via realistic simulations of diffraction, refraction, and scattering in tissues AK Glaser, UW Seattle
; Y Chen, UW Seattle; JTC Liu*, UW Seattle
Abstract: There has been great interest in developing optical-sectioning microscopes, including light-sheet microscopes, for sub-cellular-resolution imaging of tissues both for biological investigations and clinical applications. Unfortunately, conventional Monte-Carlo tissue scattering simulations do not account for certain effects that are often significant for high-resolution tissue microscopy, such as diffraction and refractive beam-steering/aberrations. Therefore, our group has been developing various improved simulation methods to more-realistically investigate and optimize the performance of microscopes for disease detection and surgical guidance. We will discuss the advantages of these techniques, including an enhanced Monte-Carlo technique and a fractal model of refractive-index turbulence, in the context of confocal and light-sheet microscopes being developed within our group.
11:00 Sub-diffusive imaging of tissue microstructure in a wide field of view SC Kanick*, Dartmouth College
Abstract: This study uses structured light imaging to provide quantitative wide-field maps of biomarkers of tissue microstructure. Reflectance images sampled over multiple spatial frequencies allow independent separation of absorption and scattering properties that independently define density and fractal dimension. This multi-scale scatter imaging approach is used to differentiate tissue types in a preclinical murine tumor model. The approach is also translated in a pilot clinical investigation to differentiate the microstructure of tissue types from samples obtained during breast conserving surgeries.