Medical Physics Seminar – Wednesday, May 8, 2013
CAMERON LECTURE: Medical Imaging in Thick Tissues Using Diffuse Optics
Dr. Bruce J. Tromberg (guest of Dr. Paul J. Campagnola)
Laser Microbeam & Medical Program, Beckman Laser Institute & Medical Clinic, University of California, Irvine, CA 92614 - USA-
Quantitative imaging in thick tissues is a significant challenge due to distortions from multiple light scattering. Several methods have been developed to quantify multiple light scattering and measure tissue function and composition. This talk describes the development of Diffuse Optical Spectroscopy and Imaging (DOSI) using spatially- and temporally-modulated sources and model-based analyses. DOSI is capable of dynamic in vivo functional imaging with variable, but limited, spatial localization. Quantitation of multiple optical contrast elements including absorption, scattering, fluorescence, and speckle can be achieved using methods for controlling optical path length in conjunction with computational models. This allows formation of 2 and 3D images of various optical and physiological properties such as blood flow, vascular density, extracellular matrix composition, and cellular metabolism. Particular emphasis is placed on determining the tissue concentration of oxy- and deoxyhemoglobin, lipid, and water, as well as tissue scattering parameters. Clinical study results will be shown highlighting the sensitivity of broadband DOSI to breast tumor metabolism with sufficient sensitivity for cancer detection and therapeutic drug monitoring. Broadband spatial frequency-domain imaging is used in pre-clinical animal models to dynamically map intrinsic brain signals, monitor the efficacy of chemotherapeutic agents, and form depth-resolved tomographic images of fluorescence and hemodynamics. These findings will be placed in the context of conventional imaging methods in order to assess the current and future role of diffuse optics in medical imaging.
Biosketch
Dr. Tromberg is the Director of the Beckman Laser Institute and Medical Clinic (BLI) at the University of California, Irvine (UCI) and principal investigator of the Laser Microbeam and Medical Program (LAMMP), an NIH National Biomedical Technology Center. He is a Professor in the departments of Biomedical Engineering and Surgery, co-leads the Onco-imaging and Biotechnology Program in UCI’s Chao Family Comprehensive Cancer Center, and has been a member of the BLI faculty since 1990. His research interests are in Biophotonics and Biomedical Optics, including diffuse optics, non-linear microscopy, cancer imaging, and photodynamic therapy.