Richard G. SpencerSpeaker
Richard G. Spencer, MD, PhD
Director, MRI Core Facility for Translational Research National Institute on Aging, Chief, Magnetic Resonance Imaging and Spectroscopy Section National Institute on Aging, Intramural Research Program National Institutes of Health
Title: Magnetic Resonance Relaxometry and Macromolecular Mapping: An Inverse Problem Framework
Abstract: There is an ongoing need for non-invasive identification of macromolecular changes in tissue. An important application is to the diagnosis of early osteoarthritis (OA).Our work in this area combines basic science studies in magnetic resonance imaging and relaxometry with emerging methodologies that carry translational potential. We will discuss multi-exponential transverse relaxation analysis as a means to identify underlying macromolecular compartments in normal and degraded cartilage, as well as important extensions of this work, based on higher dimensional relaxometry and compressed sensing. We will describe the mathematical setting for this work as a linear inverse problem. Further work in human subjects requires introduction of a nonlinear model system. We will describe several approaches to these problems and indicate the potential for improved detection of early cartilage degradation. Our methods are also applicable to directly mapping myelin in the brain, and we have obtained results showing myelination pattern alterations with age and in cognitive impairment. All of these studies are centered around the clinical goal of improving the ability of magnetic resonance methods to diagnose pathology and to monitor disease progression.