The visualization of structures and functions by imaging plays an increasingly important role in biologic and medical research. In this respect magnetic resonance imaging (MRI) offers detailed and completely noninvasive insights into the body of animals and humans. Thus, apart from its wide use in diagnostic imaging, MRI emerges as an indispensable tool in biomedical and translational research.
It is our primary aim to further develop and apply MRI methods that provide novel insights into the anatomy and physiology of animals and humans. Respective projects range from advanced acquisition and reconstruction techniques to functional studies of the human brain. A large variety of different MRI techniques allows us to link molecular and genetic information to function at the system level by investigations of genetically modified animals.
Our core competence combines MRI methodology with interdisciplinary research in the biomedical sciences. Extending into translational research, many of our goals are achieved through strategic collaborations with researchers and clinicians.
Methodology – MRI Movies in Real Time
In the mid-eighties, we invented a new principle for the acquisition of rapid magnetic resonance images (FLASH) that revolutionized the scientific potential and clinical impact of MRI. Current advances are based on non-Cartesian spatial encoding, data undersampling, and image reconstruction by regularized nonlinear inversion. These approaches may provide quantitative maps of physiologic parameters or offer even faster data acquisitions that allow for imaging of dynamic processes in real time – yielding MRI movies of speech production, turbulent blood flow, or the beating heart.
Our work focuses on diverse studies of the functional organization of the human brain (functional MRI) and its axonal connectivity (diffusion-weighted MRI). The latter technique provides information about the orientational dependence of the anisotropic water mobility in brain tissue and may be exploited for identifying bundles of myelinated axons in white matter. Parameters such as the main diffusion direction then allow for three-dimensional reconstructions of nerve fiber tracts in the living brain.
Biomedical Research – Mouse Models
Basic research using transgenic animals requires noninvasive approaches to determine the functional relevance of genes and proteins in the intact organism. As a consequence, there is a growing demand for MRI studies of animal brain: mainly of mice and with a special emphasis on structural, metabolic, and functional assessments at high spatial resolution. An important MRI advantage are follow-up studies of individual animals to monitor disease progression or novel therapeutic interventions.