Biomedical Engineering, Medicine, Neuroscience, Physics, Radiology
University of Wisconsin-Madison
My research lab focuses on the the field of magnetic resonance imaging (MRI) of the human brain. Our goal is the development and application of new MR methods to visualize the structure and function of the brain and to translate these methods to the hospital for clinical diagnosis. One of the areas upon which we concentrate our research is functional MRI (fMRI). FMRI allows us to visualize both the temporal and spatial patterns of brain activity in response to different stimuli. We are particularly interested in the development of new analysis methods to improve our understanding of brain function.
In addition to analyzing brain activation, we are also developing techniques to explore brain connectivity using diffusion tensor imaging (DTI) and the concept of effective connectivity. As implemented in MRI, DTI is a noninvasive imaging technique that can be used to probe the intrinsic diffusion characteristics of tissue. Brain tissue where diffusion is restricted or anisotropic (white matter) will appear at a different level of brightness in a DTI image than tissue with isotropic diffusion (gray matter). As a result, DTI is extremely useful for providing exquisitely detailed in vivo maps of major white matter fiber pathways. Techniques for diffusion imaging are evolving rapidly. Diffusion MRI research has been shown to have important applications, especially in stroke, the effects of tumors, degenerative diseases and brain injury.
Effective connectivity describes the integration within and between functionally specialized areas of the brain. Regions of the brain are located using fMRI. Integration of these regions is achieved through the information gained from DTI. We explore effective connectivity in a variety of large-scale neurocognitive networks using different mathematical modeling techniques, including dynamic causal modeling. Our clinical emphasis is in Parkinson’s disease, patients with schizophrenia and patients with balance disorders.