Harnessing the Power of Magnetic Resonance Physics to Study Cerebral Aging and Dementias

Water molecules within biological tissues undergo interactions with their environment through several processes including nuclear relaxation, magnetization transfer, chemical exchange, and diffusion. These processes are sensitive to various underlying local tissue properties such as density, microstructure, temperature, acidity, composition, and geometry. Through use of virtually unlimited combinations of static and spatially varying magnetic fields, or radiofrequency pulses formalisms, magnetic resonance imaging (MRI) provides unique sensitivity and specificity to probe these mechanisms in all biological tissues. Recent advances in acquisition strategies, hardware designs, computational analyses, signal modeling, and sequence pulse paradigms have positioned MRI as a powerful emerging noninvasive modality to studying biological tissue, from muscle to central nervous system, from mice to human, and from in-vitro to in-vivo, exhibiting extraordinary sensitivity and specificity in differentiating normal from abnormal cell-level processes. These techniques are based, but not limited to, on multicomponent relaxometry or diffusion, magnetization transfer, high-dimensional imaging, susceptibility imaging, cerebral functioning, etc. Using this technology to examine changes in tissue microstructure and function in aging or pathology has the potential to provide a window into the underlying age-related diseases’ biology and mechanisms, and to nominate new MR biomarkers for longitudinal assessment and targets for intervention. The purpose of my talk is to provide an overview about some of these advanced MRI techniques, and their application to provide new insights into white matter maturation and degenerations in normative aging and dementias.