Methodologic advances in spatially resolved NMR yield unique insights into the anatomy, metabolism, and function of human and animal brains. In particular, localized magnetic resonance spectroscopy (MRS) and functional magnetic resonance imaging (MRI) pave the way for new questions that range from basic neurobiologic research, e.g. involving transgenic animal models, to studies of human cognition in normal subjects and patients with psychiatric disorders. This conceptional link between basic and clinical neuroscience is expected to yield significant contributions toward a better understanding of the human brain under both physiologic and pathologic conditions. In 1985, we solved a key problem in MRI by describing a new principle for the acquisition of rapid NMR images. The FLASH method revolutionized the scientific potential and clinical impact of MRI and strongly supported its commercial breakthrough as the leading modality in diagnostic imaging – with almost 100 million examinations per year worldwide.
Our research focus encompasses methodologic developments as well as system-oriented applications in the field of neurobiology. For example, non-Cartesian encoding strategies and image reconstructions by nonlinear inversion allow for advanced techniques such as parallel imaging and real-time MRI. MRS provides access to the regional cellular composition and intracellular metabolism, which proves invaluable for an early biochemical characterization of neurodegenerative disorders and inborn errors of metabolism in children. Neuroimaging studies of mutant mice help to characterize the function of specific genes at the system level and assess novel therapeutic regimens such as tissue repair strategies.
Another major part of our research is devoted to functional neuroimaging of the human brain. The noninvasive visualization of human brain function by MRI exploits the fact that changes in neural activity are translated into a focal change of the intravascular concentration of paramagnetic deoxyhemoglobin. The dynamic MRI signal changes associated with these hemodynamic responses may be mapped at an unsurpassed spatial resolution and with sufficient sensitivity for unraveling the functional anatomy even of single brief cortical events. Selected applications range from primary sensory processing in the visual or motor system to higher cognitive processing in relation to language comprehension or memory. Recent studies address the influence of top-down processes onto the perception of the brain's sensory input, for example, via attentional modulation and explore the potential for neurofeedback, which allows subjects to self-control their own brain activity in selected regions.