Abstract: Conventional magnetic resonance (MR) imaging scans suffer from limited resolution that prohibits the visualization of individual cells thus providing information at coarse length scales. To obtain information at smaller length scales, the MR signal can be sensitized to self-diffusion of water molecules whose motional history is influenced by the local microstructure. Starting from the fundamentals, I will discuss the essential features of diffusion MR that makes it a powerful probe to characterize tissue and material microstructure. Emphasis will be placed on an alternative diffusion MR pulse sequence, the double pulsed field gradient (double-PFG) technique, that could be used to characterize the size, shape, and orientational distribution of cellular compartments without the need to apply strong magnetic field gradients. Theoretical predictions as well as early experimental findings demonstrate that double-PFG MR could be a powerful technique for monitoring morphological changes in tissue, and, as such, a valuable diagnostic tool.
Evren Özarslan graduated with a Bachelor of Science in Physics from the University of Illinois at Urbana-Champaign in 1999. He obtained his M.S. degree in Biomedical Engineering in 2003 and Ph.D. in Physics in 2004, both from the University of Florida. Since 2005 Dr. Özarslan has been a member of the Section on Tissue Biophysics and Biomimetics (STBB) at the National Institutes of Health (NIH). Starting October this year, Dr. Özarslan assumed a scientist position with the Henry M. Jackson Foundation, and has been continuing his research jointly at the Center for Neuroscience and Regenerative Medicine and STBB. His current research is on physical modeling of biological tissue and other porous media with the specific aim of characterizing the microstructure of the specimen using noninvasive magnetic resonance based techniques. Dr. Özarslan's research is interdisciplinary in nature, and has in common with a wide range of disciplines, from magnetic resonance imaging and materials science to mathematical, chemical, and biological physics.