For the past 26 years, researchers in the Garwood laboratory have had a focus on developing cutting-edge MRI and MR spectroscopy techniques and on exploiting them in studies of tissue function, metabolism, and microstructure. An emphasis has been on identifying and validating quantitative metrics to assess normal and disease states non-invasively with imaging, and on applying them to learn about metabolism, hemodynamics, and tissue micro-environment. On the technical side, the Garwood group has recently made a significant advancement in the way MRI is performed - a technique called SWIFT. SWIFT exploits time-shared RF excitation and acquisition to preserve signals from water molecules possessing extremely short transverse relaxation times, T2 and T2*. With SWIFT, broadband frequency-swept excitation, together with extremely short acquisition delay, make it possible to also preserve frequency-shifted signals in the vicinity of magnetic objects. For example, magnetically-labeled nanoparticles (e.g., SPIOs), which cause signal voids in conventional MR images, give rise to positive contrast (bright spots) in SWIFT images, thus improving the capability to track and quantify targeted contrast agents and molecular therapies, as well as magnetically-labeled cells. Finally, the Garwood group has a focus on the physics of nuclear magnetic resonance relaxation, in an effort to improve the sensitivity and specificity of MRI for disease characterization, diagnosis, and treatment monitoring. In particular, we are developing ways to "tune" MRI's specificity to certain dynamic processes in tissues (e.g., assessing the tumbling times and exchange rates of different pools of tissue water) and we are investigating their utility as quantitative markers of neurodegeneration and cancer aggressiveness, and as early indicators of response to treatments. These methods are currently in pre-clinical and clinical trials (lung, breast, and brain cancers; Parkinson's disease, and multiple sclerosis) in collaboration with other faculty in the University of Minnesota and elsewhere.
